20250829Exhibit No. 1 - Avista 2024 Idaho ACR.pdf

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2 0 2 4Idaho Annual Conservation Report
September 1, 20 25

All product and company names contained within this document are either trademarks(TM)or registered(@)trademarks of their respective holders.Use of them does
not imply any affiliation with or endorsement by them.All specifications are subject to change without notice.
All forward-looking statements contained in this document are based on underlying assumptions(many of which are based,in turn,upon further assumptions).These
statements are subject to a variety of risks,uncertainties,and other factors.Most of these factors are beyond our control and may have a significant effect on our
operations,results of operations,financial condition,or cash flows,which could cause actual results to differ materially from those anticipated in our statements.
Such risks,uncertainties,and other factors include,among others,those in our most recent annual report on Form 10-K,or quarterly report on Form 10-Q,filed with the
Securities and Exchange Commission.Those reports are available on our website at avistacorp.com.
Front cover:Spirit Lake,Idaho

TABLE OF CONTENTS
ExecutiveSummary.............................................................................................................1
IdahoAchievements............................................................................................................2
PortfolioTrends..............................................................................................................................................................................................3
Expenditures.....................................................................................................................................................................................................4
Cost-Effectiveness ..............................................................................................................5
ImpactEvaluation..........................................................................................................................................................................................6
TariffRider Balances............................................................................................................6
Commercial/Industrial Sector.................................................................................................9
Overview...........................................................................................................................................................................................................9
PortfolioPerformance...................................................................................................................................................................................9
VerifiedSavings.....................................................................................................................................................................................10
Cost-Effectiveness......................................................................................................................................................................................... I I
Marketing.......................................................................................................................................................................................................I I
Powerof Change.................................................................................................................................................................................12
BusinessPartner Program..........................................................................................................................................................................12
Program-by-Program Summaries.............................................................................................................................................................13
Commercial/Industrial Site-Specific Program..............................................................................................................................13
Description.....................................................................................................................................................................................13
ProgramActivities........................................................................................................................................................................13
ProgramChanges.........................................................................................................................................................................14
ImpactEvaluation.......................................................................................................................................................................14
Plansfor 2025...............................................................................................................................................................................14
Commercial/Industrial Prescriptive Lighting Program...............................................................................................................15
Description.....................................................................................................................................................................................15
ProgramActivities........................................................................................................................................................................15
ProgramChanges.........................................................................................................................................................................15
ProgramMarketing.......................................................................................................................................................................17
ImpactEvaluation.......................................................................................................................................................................17
Recommendations........................................................................................................................................................................17
Plansfor 2025...............................................................................................................................................................................17
Small Business Direct-Install Lighting Program...........................................................................................................................18
Description.....................................................................................................................................................................................18
ProgramActivities........................................................................................................................................................................18
ProgramChanges.........................................................................................................................................................................18
ImpactEvaluation.......................................................................................................................................................................18
Recommendations........................................................................................................................................................................ 19
Plansfor 2025............................................................................................................................................................................... 19
2024 Idaho Annual Conservation Report

Commercial/Industrial Prescriptive Non-Lighting Programs...................................................................................................19
Description/Program Activities.................................................................................................................................................19
ProgramMarketing.......................................................................................................................................................................20
ImpactEvaluation.......................................................................................................................................................................20
Recommendations........................................................................................................................................................................21
Plansfor 2025...............................................................................................................................................................................21
MidstreamProgram.............................................................................................................................................................................21
Description.....................................................................................................................................................................................21
ProgramActivities........................................................................................................................................................................21
ProgramChanges.........................................................................................................................................................................22
ImpactEvaluation.......................................................................................................................................................................22
Recommendations........................................................................................................................................................................22
Plansfor 2025...............................................................................................................................................................................22
Building Operator Certification Program......................................................................................................................................23
Description.....................................................................................................................................................................................23
ProgramActivities........................................................................................................................................................................23
Plansfor 2025...............................................................................................................................................................................23
ResidentialSector............................................................................................................. 25
Overview.........................................................................................................................................................................................................25
PortfolioPerformance.................................................................................................................................................................................25
ImpactEvaluation................................................................................................................................................................................26
Cost-Effectiveness.........................................................................................................................................................................................27
Marketing.......................................................................................................................................................................................................27
AtHome with Lisa...............................................................................................................................................................................28
Powerof Change.................................................................................................................................................................................28
Program-by-Program Summaries.............................................................................................................................................................29
MidstreamProgram.............................................................................................................................................................................29
Description.....................................................................................................................................................................................29
ProgramActivities........................................................................................................................................................................29
ProgramChanges.........................................................................................................................................................................29
ImpactEvaluation.......................................................................................................................................................................30
Recommendations........................................................................................................................................................................30
Plansfor 2025...............................................................................................................................................................................30
ResidentialShell Program..................................................................................................................................................................31
Description.....................................................................................................................................................................................31
ProgramActivities........................................................................................................................................................................31
ImpactEvaluation.......................................................................................................................................................................31
Recommendations........................................................................................................................................................................32
Plansfor 2025...............................................................................................................................................................................32
Residential Home Energy Audit Program.....................................................................................................................................33
Description.....................................................................................................................................................................................33
ProgramActivities........................................................................................................................................................................33
2024 Idaho Annual Conservation Report

ImpactEvaluation.......................................................................................................................................................................34
Plansfor 2025...............................................................................................................................................................................34
Residential ENERGY STAR/NEEM Manufactured Housing Program....................................................................................34
Description.....................................................................................................................................................................................34
ProgramActivities........................................................................................................................................................................34
ImpactEvaluation.......................................................................................................................................................................35
Recommendations........................................................................................................................................................................35
Plansfor 2025...............................................................................................................................................................................35
ResidentialAppliances Program......................................................................................................................................................35
Description.....................................................................................................................................................................................35
ProgramActivities........................................................................................................................................................................36
ImpactEvaluation.......................................................................................................................................................................37
Recommendations........................................................................................................................................................................37
Plansfor 2025...............................................................................................................................................................................37
Residential Fuel-Efficiency Program................................................................................................................................................38
Description.....................................................................................................................................................................................38
ProgramActivities........................................................................................................................................................................38
ImpactEvaluation.......................................................................................................................................................................38
Recommendations........................................................................................................................................................................39
Plansfor 2025...............................................................................................................................................................................39
Low-Income Sector........................................................................................................... 41
Program-by-Program Summaries.............................................................................................................................................................41
Low-Income Program..........................................................................................................................................................................41
Description.....................................................................................................................................................................................41
ProgramActivities........................................................................................................................................................................42
ProgramChanges.........................................................................................................................................................................43
CustomerOutreach....................................................................................................................................................................43
Cost-Effectiveness.........................................................................................................................................................................45
ImpactEvaluation.......................................................................................................................................................................45
Plansfor 2025...............................................................................................................................................................................45
PilotPrograms ................................................................................................................. 47
Program-by-Program Summaries.............................................................................................................................................................47
BuildingEnergy IQ Pilot Program....................................................................................................................................................47
Description.....................................................................................................................................................................................47
ProgramActivities........................................................................................................................................................................47
ProgramChanges.........................................................................................................................................................................47
Plansfor 2025...............................................................................................................................................................................47
Compressed Air Leak Detection Pilot Program..........................................................................................................................48
Description.....................................................................................................................................................................................48
ProgramActivities........................................................................................................................................................................48
2024 Idaho Annual Conservation Report

Researchand Development......................................................................................................................................................................49
Inland Northwest Center for Energy and Decarbonization.....................................................................................................49
RegionalMarket Transformation .......................................................................................... 51
ElectricEnergy Savings Share...................................................................................................................................................................51
NaturalGas Energy Savings Share..........................................................................................................................................................51
Glossaryof Terms............................................................................................................. 53
Appendicesand Supplements .............................................................................................. 65
LIST OF TABLES
Table I — Energy-Efficiency Savings and Cost-Effectiveness Results.....................................................................................................2
Table2—Idaho Electric Achievements............................................................................................................................................................2
Table 3—Idaho Natural Gas Achievements...................................................................................................................................................2
Table 4—Energy-Efficiency Savings by Sector—Electric...........................................................................................................................3
Table 5 — Energy-Efficiency Savings by Sector — Natural Gas...................................................................................................................3
Table 6 — Annual Conservation Plan Budget to Actual Expenditures Comparison...........................................................................4
Table 7— Portfolio Cost-Effectiveness Results — Electric............................................................................................................................5
Table 8— Portfolio Cost-Effectiveness Results— Natural Gas...................................................................................................................5
Table9—Tariff Rider Activity...............................................................................................................................................................................6
Table 10 — Commercial/Industrial Verified vs Planned Savings — Electric.............................................................................................9
Table I I — Commercial/Industrial Verified vs Planned Savings — Natural Gas..................................................................................10
Table 12 — Commercial/Industrial Cost-Effectiveness Results — Electric.............................................................................................
Table 13 — Commercial/Industrial Cost-Effectiveness Results — Natural Gas.....................................................................................
Table 14 — Commercial/Industrial Site-Specific Program Metrics..........................................................................................................13
Table 15 — Commercial/Industrial Site-Specific Program Impact Findings — Electric......................................................................14
Table 16 — Commercial/Industrial Site-Specific Program Impact Findings — Natural Gas..............................................................14
Table 17 — Commercial/Industrial Prescriptive Lighting Program Metrics..........................................................................................15
Table 18 — Commercial/Industrial Prescriptive Lighting Program Changes.........................................................................................15
Table 19 — Commercial/Industrial Prescriptive Lighting Program Impact Findings — Electric.......................................................17
Table 20 — Small Business Direct-Install Lighting Program Metrics.......................................................................................................18
Table 21 — Small Business Direct-Install Lighting Program Impact Findings — Electric...................................................................18
Table 22 — Commercial/Industrial Prescriptive Non-Lighting Program Metrics.................................................................................20
Table 23 — Commercial/Industrial Prescriptive Non-Lighting Program Impact Findings — Electric.............................................20
Table 24 — Commercial/Industrial Prescriptive Non-Lighting Program Impact Findings — Natural Gas....................................20
Table 25 — Commercial/Industrial Midstream Program Metrics.............................................................................................................21
2024 Idaho Annual Conservation Report

Table 26 — Commercial/Industrial Midstream Program Impact Findings — Electric.........................................................................22
Table 27 — Commercial/Industrial Midstream Program Impact Findings — Natural Gas................................................................22
Table 28 — Building Operator Certification Program Metrics.................................................................................................................23
Table 29 — Residential Programs Verified vs Planned Savings — Electric.............................................................................................25
Table 30 — Residential Programs Verified vs Planned Savings — Natural Gas....................................................................................26
Table 31 — Residential Cost-Effectiveness Results — Electric...................................................................................................................27
Table 32 — Residential Cost-Effectiveness Results — Natural Gas..........................................................................................................27
Table 33 — Residential Midstream Program Metrics..................................................................................................................................29
Table 34 — Residential Midstream Program Impact Findings — Electric...............................................................................................30
Table 35 — Residential Midstream Program Impact Findings — Natural Gas......................................................................................30
Table 36 — Residential Shell Program Metrics..............................................................................................................................................31
Table 37 — Residential Shell Program Impact Findings — Electric..........................................................................................................31
Table 38 — Residential Shell Program Impact Findings — Natural Gas..................................................................................................31
Table 39 — Residential Home Energy Audit Program Metrics.................................................................................................................33
Table 40 — Residential Home Energy Audit Program Impact Findings — Electric.............................................................................34
Table 41 — Residential ENERGY STAR/NEEM Manufactured Housing Program Metrics................................................................34
Table 42 — Residential ENERGY STAR/NEEM Manufactured Housing Program Impact Findings — Electric.............................35
Table 43 — Residential Appliances Program Metrics..................................................................................................................................36
Table 44 — Residential Appliances Program Impact Findings — Electric..............................................................................................37
Table 45 — Residential Appliances Program Impact Findings — Natural Gas......................................................................................37
Table 46 — Residential Fuel-Efficiency Program Metrics...........................................................................................................................38
Table 47 — Residential Fuel-Efficiency Program Impact Findings — Electric........................................................................................38
Table 48— Low-Income Program Metrics......................................................................................................................................................41
Table 49 — Low-Income Program Reported Savings...................................................................................................................................42
Table 50 — Low-Income Program Approved Measure List.......................................................................................................................42
Table 51 — Low-Income Program Qualified Rebate Measure List.........................................................................................................42
Table 52 — Low-income Program Cost-Effectiveness Results — Electric..............................................................................................45
Table 53 — Low-Income Program Cost-Effectiveness Results — Natural Gas......................................................................................45
Table 54 — NEEA Energy Savings and Participation Costs.......................................................................................................................51
LIST OF FIGURES
Figure I —Electric and Natural Gas Service Areas.......................................................................................................................................
Figure 2—Commercial/Industrial Power of Change Ads....................................................................................................................... 12
Figure 3— Residential Power of Change Ads.............................................................................................................................................28
Figure 4—Residential Appliances Program Flyer......................................................................................................................................36
Figure 5 — Low-Income Program Weatherization Flyer............................................................................................................................44
2024 Idaho Annual Conservation Report

LIST OF APPENDICES AND SUPPLEMENTS
Appendix A—2024 Electric Impact Evaluation Report
Appendix B—2024 Natural Gas Impact Evaluation Report
Appendix C —2024 Cost-Effectiveness Tables
Appendix D — 2024 Expenditures by Program
Appendix E—2024 Energy-Efficiency Activity by Program
Appendix F— NEEA 2024 Annual Savings Report— Electric
Appendix G—NEEA 2024 Annual Savings Report—Natural Gas
Appendix H — Idaho Furnace Billing Analysis Memorandum
2024 Idaho Annual Conservation Report

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2024 Idaho Annual Conservation Report

EXECUTIVE SUMMARY
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EXECUTIVE SUMMARY
For nearly 50 years, Avista's energy-efficiency programs have helped customers in Idaho discover innovative ways
to conserve energy, live more comfortably, operate businesses more efficiently, and save money. This 2024 Annual
Conservation Report (ACR) summarizes Avista's efforts to support the energy needs of residential and commercial
customers across the service territory.
FIGURE 1 - ELECTRIC AND NATURAL GAS SERVICE AREAS
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Electric and • to GraMM•
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NaturalService Areas IDAHO
OREGON
Electric ■
Natural Gas ■
Electric and Natural Gas ■ SE FANS
Energy efficiency continues to be a least-cost resource for the company, and 2024 was a very strong year for
conservation, with programs achieving electric savings significantly beyond targets. These achievements built on
changes to the portfolio implemented in early 2023 to encourage increased program participation. Avista's Midstream
and Small Business Direct-Install Lighting programs continued to lead the portfolio in kWh savings. All programs
sustained a focus on affordability and flexibility, with a large emphasis on customer-centered energy solutions.
In addition to its portfolio of company and third party-implemented programs, Avista once again supported regional
market transformation efforts through the Northwest Energy Efficiency Alliance (NEEA). Reported energy-conservation
savings, cost-effectiveness, and other related data, however, are specific to local programs unless otherwise noted.
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,AIuV1STA 2024 Idaho Annual Conservation Report Pg I

IDAHO ACHIEVEMENTS
TABLE 1 - ENERGY-EFFICIENCY SAVINGS AND COST-EFFECTIVENESS RESULTS
Electric Actuals(kWh) 30,150,532 $ 17,316,094 0.82 1.41
Percent of Planned Savings/Budget 336% 322%
Annual Planned Savings/Budget 8,960,566 $ 5,376,930
Natural Gas
Natural Gas Actuals(Therms) 220,279 $ 2,282,282 1.24 1.05
Percent of Planned Savings/Budget 56% 84%
Annual Planned Savings/Budget 392,021 $ 2,725,904
Electric Conservation:For 2024,savings from NEEA's programs added an additional 6,952 MWh, bringing
the overall savings achieved from 30,151 MWh to 37,103 MWh.
TABLE 2 - IDAHO ELECTRIC ACHIEVEMENTS
Savings Achieved
MM (MWh)
Commercial/Industrial 27,695
Residential 2,391
Low-Income 65
Total Local Program 30,151
NEEA 6,952
Total
37,103
Natural Gas Conservation:After including 285,431 therms from NEEA's programs,the overall savings
achieved in 2024 was 505,710 therms.
TABLE 3 - IDAHO NATURAL GAS ACHIEVEMENTS
Savings Achieved
Commercial/Industrial 33,187
Residential 185,712
Low-Income 1,380
Total Local Program 220,279
NEEA 285,431
Total 505,710
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Pg 2 2024 Idaho Annual Conservation Report AdV15TA

Portfolio Trends
Avista achieved significantly higher-than-anticipated electric energy savings in 2024. A key driver was enthusiastic
participation in the Small Business Direct-Install Lighting and Midstream programs (particularly Midstream residential
measures). Substantial savings were also achieved through the commercial/industrial Site-Specific and Prescriptive
Lighting programs.
• The Small Business Direct-Install Lighting Program achieved 50 percent of the kWh savings for the entire
electric portfolio in 2024.This program remains extremely popular with customers and trade allies alike,for
its simplicity and little to no out-of-pocket costs for customers.
About 17 percent of portfolio savings came from the Site-Specific Program, perhaps indicating some market
recovery in the commercial/industrial segment, particularly for lighting upgrades.
TABLE 4 - ENERGY-EFFICIENCY SAVINGS BY SECTOR - ELECTRIC
Planned Savings Achieved Savings %of Planned
(kWh) Savings Achieved
Commercial/Industrial 7,215,555 27,694,876 384%
Residential 1,623,462 2,390,778 147%
Low-Income 121,549 64,878 53%
Total 8,960,566 30,150,532 336%
Natural gas programs, on the other hand, achieved less therm savings than anticipated. While residential programs
reached about three-quarters of the company's planned savings goal, commercial/industrial programs achieved around
one-third.
• The Low-Income natural gas program achieved significantly higher savings than anticipated. The Community
Action Partnership (CAP) of Lewiston was better able to address labor shortages in 2024, compared to prior
years.
• Residential programs were buoyed by very robust participation in the Midstream Program.
• The company continued to see diminished participation in commercial/industrial natural gas programs, as
pressure on capital expenditures remained high and interest rates and inflation contributed to uncertainty.
TABLE 5 - ENERGY-EFFICIENCY SAVINGS BY SECTOR - NATURAL GAS
Planned Savings Achieved Savings %of Planned
(Therms) (Therms) Savings Achieved
Commercial/Industrial 101,325 33,187 33%
Residential 290,201 185,712 64%
Low-Income 496 1,380 278%
Total ,- 392,021 220,279 56%
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,4�-IIIVLSTA© 2024 Idaho Annual Conservation Report Pg 3

Expenditures
As part of Avista's annual business planning process, the company sets an expectation to pursue all cost-effective
measures possible under Tariff Schedules 90 and 190. Because of this mandate, variances may exist between planned
and actual spending each year. For 2024, expenditures for the company's conservation programs far exceeded
anticipated budgets. On the electric side, actual spending was approximately 3.5 times the planned spend —in
line with the achievement of 336 percent of planned savings. On the natural gas side, actual spending closely
aligned with planned spending, though savings fell short of projections. Overall, the company saw a reduction
in incentive expenditures and higher-than-expected non-incentive costs during this program year. These costs
included administrative expenses for the Midstream Program, Home Energy Audit Program, and Regional Market
Transformation (which achieved more therms than planned).
Table 6 provides a detailed comparison of budgeted to actual energy-efficiency expenditures by fuel type.
TABLE 6 - ANNUAL CONSERVATION PLAN BUDGET TO ACTUAL EXPENDITURES COMPARISON
2024 Planned Expenses 2024 Actual Expenses
Incentives $ 2,905,424 $ 13,643,398
Non-Incentives and Labor $ 1,359,845 $ 2,558,375
MT,CPA,EM&V $ 1,1 1 1,661 $ 1,1 14,321
Total Electric Expenditures $ 5,376,930 $ 17,316,094
Natural Gas
Incentives $ 2,441,310 $ 1,604,312
Non-Incentives and Labor $ 151,094 $ 381,866
MT,CPA,EM&V $ 133,500 $ 296,104
Total Natural Gas Expenditures $ 2,725,904 $ 2,282,282
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Pg 4 2024 Idaho Annual Conservation Report III/i�/�STA

COST- EFFECTIVENESS
Avista's energy-efficiency portfolio offerings are evaluated throughout implementation, as well as at the conclusion of
each program year, to gauge cost-effectiveness. Cost-effectiveness tests are utilized to determine whether a program
is beneficial from the company's and customers' perspectives. Avista's cost-effectiveness goal for the electric and
natural gas program portfolios is a Utility Cost Test(UCT) above 1.00, indicating that benefits to the utility exceed the
costs of implementing the program.
The electric portfolio achieved a UCT ratio of 1.41 in 2024, and the company's natural gas portfolio achieved a
UCT ratio of 1.05. Although declining avoided costs drove natural gas incentives downward in 2024, a change in
methodology for evaluated savings for residential natural gas furnaces resulted in higher savings per unit than in
2023. During the 2023 program year, Avista began offering its natural gas HVAC rebates through the Midstream
Program. With low realization rates for these rebates reported in the 2023 Idaho Electric Impact Evaluation Report,
Avista worked with its third-party evaluator and program implementer throughout 2024 to review savings calculations
for understanding and potential alignment in approaches or assumptions. While the impact analysis initially relied on
inputs consistent with baselines dictated by the Regional Technical Forum of the Northwest Power and Conservation
Council (RTF), evaluators determined that a billing analysis of Midstream furnace measures would be a more accurate
methodology for Avista's service territory. From 2020 to 2023, furnaces were evaluated at or above 80 therms per
unit each program year. In 2024, furnace savings determined through the billing analysis were 90 therms per unit,
compared to values in the RTF that were closer to 30 therms per unit. These significant differences in savings can be
attributed to a colder climate in the Avista service territory in Idaho compared with other regions in Southern Idaho
and Western Washington, as well as a baseline with a higher proportion of inefficient units.
TABLE 7 - PORTFOLIO COST-EFFECTIVENESS RESULTS - ELECTRIC
Cost-Effectiveness Test
Utility Cost Test(UCT) $ 23,222,846 $ 16,510,052 1.41
Total Resource Cost(TRC) $ 23,222,846 $ 28,252,370 0.82
Participant Cost Test(PCT) $ 37,174,523 $ 25,693,995 1.45
Ratepayer Impact(RIM) $ 23,222,846 $ 18,633,1 16 1.25
TABLE 8 - PORTFOLIO COST-EFFECTIVENESS RESULTS - NATURAL GAS
Cost-Effectiveness Test Benefit/Cost Ratio
UCT $ 2,052,929 $ 1,962,187 1.05
TRC $ 2,052,929 $ 1,660,247 1.24
PCT $ 3,633,250 $ 1,020,983 3.56
RIM $ 2,052,929 $ 2,090,636 0.98
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III/VISTA 2024 Idaho Annual Conservation Report Pg 5

Impact Evaluation
As a result of the impact evaluation completed by the evaluator, the following realization rates were achieved in the
Idaho program portfolio:
Electric:98 percent realization rate and 30,150,532 kWh in annual verified savings.
Natural Gas: 185 percent realization rate and 220,279 therms in annual gross savings.
TARIFF RIDER BALANCES
At the start of 2024, the Idaho electric and natural gas (aggregate) tariff rider balances were overfunded by roughly
$4.4 million. Approximately $8.1 million in tariff rider revenue was collected to fund energy efficiency during the
year, while roughly $19.6 million went to operate energy-efficiency programs. While the electric portfolio ended
the year with an $8.9 million underfunded balance, the natural gas portfolio remained overfunded by $1.8 million,
resulting in an overall underfunded balance of$7 million by the end of 2024. For electric programs,the underfunded
balance was driven by much higher-than-anticipated participation in the Small Business Direct-Install Lighting
Program. Increased participation drove much higher-than-expected savings, which in turn drove increases in costs.
The Midstream Program also saw higher-than-expected participation, which also drove cost increases, although not to
the same degree as for the Small Business Direct-Install Lighting Program. For natural gas programs, the overfunded
balance was driven primarily by lower-than-expected participation in both commercial and residential programs.
Lower-than-expected participation was driven by a number of factors, one of which was a significant drop in avoided
costs in 2024. The company responded to these changes by more aggressively managing costs; for example, reducing
marketing activities in an effort to preserve cost-effectiveness of the natural gas portfolio.
Concurrent with the filing of this ACR, Avista is filing proposed rate adjustments to both its electric and natural gas
tariffs to true-up these balances. Table 9 illustrates 2024 tariff rider activity by fuel type.
TABLE 9-TARIFF RIDER ACTIVITY
Natural Gas
Beginning Balance(Underfunded)/Overfunded $ ff 4,363,646 $� 52,658 $ 4,416,304
Energy-Efficiency Funding Collected in 2024 $ 4,091,564 $ 4,035,247 $ 8,126,812
Total Funding Available in 2024 $ 8,455,210 $ 4,087,905 $ 12,543,1 16
Energy-Efficiency Expenditures $ 17,316,094 $ 2,282,282 $ 19,598,375
Ending Balances(Underfunded)/Overfunded $ (8,860,883) $ 1,805,624 $ (7,055,259)
AIII�Pg 6 2024 Idaho Annual Conservation Report IuVJrSTA

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COMMERCIAL/INDUSTRIAL SECTOR
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COMMERCIAL/INDUSTRIAL SECTOR
Overview
Commercial/industrial customers are offered multiple pathways for participation in Avista's energy-efficiency
programs. The Midstream Program partners with distributors to ensure that the mix of HVAC, hot water, and
foodservice equipment available to contractors is energy-efficient, and Prescriptive measures offer a simple approach
for lighting, shell, variable frequency drive (VFD), and grocer-related improvements.Any savings measure not offered
through the Midstream or Prescriptive pathways is eligible for consideration through the Site-Specific Program path.
This path is designed for unique or complex projects that require customer savings calculations and/or technical
assistance from Avista's energy engineering team (such as compressed air, process equipment and controls, and
comprehensive lighting retrofits). In certain instances, a performance-based approach is used, in which incentives are
paid based on the building's performance over a multiyear period.
In 2024, Avista also continued its innovative Direct-Install Lighting Program for small businesses, offering low-to no-
cost lighting upgrades for Schedule I I and Schedule 12 customers. The program remained extremely popular with
customers and trade allies alike, accounting for more than half of electric savings in 2024. The Midstream Program
accounted for the majority of therm savings in the commercial/industrial natural gas portfolio.
Portfolio Performance
The electric program portfolio achieved nearly four times its 2024 savings goal, with over half of savings coming from
the Small Business Direct-Install Lighting Program. Most programs in the portfolio achieved more than one-and-a-half
times their savings goal.
The table below shows savings goals assigned to Avista's commercial/industrial electric programs for 2024, as well as
reported savings and percentage of goal achieved.
TABLE 10 - COMMERCIAL/INDUSTRIAL VERIFIED VS PLANNED SAVINGS - ELECTRIC
Commercial/industrial Program Planned Savings Verified Savings Percentage of
(kWh) (kWh) Planned Savings
Site-Specific 3,456,295 5,185,350 150%
Prescriptive Lighting 3,312,429 6,888,637 208%
Small Business Direct-Install Lighting 289,101 15,161,166 5,244%
Green Motors Rewind No 2024 participation
Commercial Grocer 52,091 37,199 71
Commercial Prescriptive HVAC VFD Retrofit — 115,1 11 —
Commercial Shell 15,437 16,263 105%
Midstream 90,202 172,150 191
Building Operator Certification — 119,000 —
Commercial/Industrial Total 7,215,555 27,694,876 384%
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�drW.5TA 2024 Idaho Annual Conservation Report Pg 9

The natural gas segment of the portfolio achieved 33 percent of the planned savings for 2024. The Site-Specific
Program came close to achieving planned savings; the Midstream and Shell programs, by contrast, had lower-than-
expected savings.
• The Midstream Program achieved 75 percent of therm savings for the commercial/industrial sector.
Shell and Site-Specific programs accounted for the remaining 25 percent of commercial/industrial natural gas
savings.
The table below shows planned savings assigned to Avista's commercial/industrial natural gas programs for 2024, as
well as verified savings and percentage of planned savings achieved.
TABLE 11 - COMMERCIAL/INDUSTRIAL VERIFIED VS PLANNED SAVINGS - NATURAL GAS
Commercial/industrial Program Planned Savings Verified Savings Percentage of
(Therms) (Therms) Planned Savings
Site-Specific 5,116 4,818 94%
Commercial Shell 7,202 3,600 50%
Midstream 89,007 24,769 28%
Commercial/Industrial Total 101,325 33,187 1 33%
Verified Savings
In 2024, the commercial/industrial electric portfolio reported savings of 28,795 MWh and achieved evaluated savings
of 27,695 MWh, resulting in a realization rate of 96.2 percent. The natural gas portfolio reported 35,812 therms and
achieved evaluated savings of 33,187 therms, resulting in a 92.7 percent realization rate (see the program-specific
summaries later in this section for individual program realization rates). Further discussion of realization rates is
included in the impact evaluation reports appended to this report.
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Pg 10 2024 Idaho Annual Conservation Report �IIIVIsTA'

Cost-Effectiveness
Tables 12 and 13 show the commercial/industrial sector cost-effectiveness results by fuel type.
TABLE 12 - COMMERCIAL/INDUSTRIAL COST-EFFECTIVENESS RESULTS - ELECTRIC
Cost-Effectiveness Test Benefits Costs Benefit/Cost Ratio
TRC $ 18,758,389 $ 26,148,400 0.72
UCT $ 18,758,389 $ 15,135,905 1.24
PCT $ 31,827,752 $ 24,081,858 1.32
RIM $ 18,758,389 $ 17,086,053 1.10
TABLE 13 - COMMERCIAL/INDUSTRIAL COST-EFFECTIVENESS RESULTS - NATURAL GAS
Cost-Effectiveness Test
TRC $ 238,463 $ 300,269 0.79
UCT $ 238,463 $ 235,653 1.01
PCT $ 429,759 $ 236,108 1.82
RIM $ 238,463 $ 255,005 0.94
Marketing
Avista continued a robust approach to commercial/industrial energy-efficiency marketing in 2024. The company's
campaigns shared rebate programs, customer success stories, and ways to save energy. Messages were deployed
across multiple channels, including print, digital, search, streaming and broadcast, social media, email, website,
newsletters, and more. Additionally, the company's regional account executives continued building program
awareness and engagement by managing business customer projects and relationships.
Avista's energy-efficiency rebate program ads were refreshed in 2024, engaging customers with multiple messages.
Because this customer segment holds vast potential for energy savings, a new industrial case study and several
small-business project highlights were developed to showcase successful experiences. Existing case studies were also
leveraged, such as Harvester Restaurant and Luxury Living, during major event sponsorship and broadcast media buys.
Short stories were shared frequently across Avista's social media channels, generating interest and engagement in
rebate and direct-install programs. The purpose of these efforts was to bring the business audience into the energy-
efficiency conversation, helping them see how their peers are benefiting from Avista's programs.
Throughout the year, Avista reached out to business customers directly via email, offering energy-saving advice and
program information. For example,an email sent to school districts within Avista's service areas detailed opportunities
through the Department of Energy's Renew America's Schools Program and Energy Champions Leading the
Advancement of Sustainable Schools. Avista also continued its longstanding e-newsletter, Energy Solutions, directing
customers to helpful programs at myavista.com.
AlIN
,air-1VISTAW 2024 Idaho Annual Conservation Report Pg I I

Avista offered a fall open house focused on energy-efficiency programs, where program managers, energy engineers,
and account executives welcomed commercial/industrial trade ally vendors and contractors in an effort to further
engage these organizations. Energy-efficiency rebate programs and services were discussed and shared, with the
intention that trade allies would advance their participation on behalf of their customers.
Power of Change
Avista took a fresh creative approach to promoting energy efficiency in 2024 with the launch of a campaign called
Power of Change. The campaign positions energy efficiency as an approachable way into the broader energy
conversation, and messaging includes energy-saving tips and program promotion.
Power of Change is the first large-scale paid social media advertising campaign in Avista's history. The decision to
enter the paid social media market was driven by changing customer preferences and demographics. Ads ran on
Meta, X, Linkedln, TikTok, and YouTube, in addition to digital display and streaming, and messaging was included
in sponsorship activations for local sporting events. Ads ran in six-week phases, with a total of six business ads per
phase.
FIGURE 2 - COMMERCIAL/INDUSTRIAL POWER OF CHANGE ADS
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Business Partner Program
The Business Partner Program (BPP) raises awareness of Avista's programs among rural small-business customers in
Idaho and Washington, providing information on energy audits, budget billing plans, and energy-efficiency rebates.
Due to the program's success, it expanded in fall 2023 to include both rural and urban small-business customers.
Through this program,Avista continues to offer the Trade Ally Bid Program,through which various vendors (e.g.,
lighting, HVAC, window, and insulation) provide cost estimates to customers for energy-efficiency upgrades.
Collaboration with trade ally partners enables Avista to offer energy assessments, walking customers through the
incentive process and helping them obtain project bids. The Trade Ally Bid Program has empowered small-business
customers who may lack the time, budget, or access to contractors to make improvements toward energy efficiency.
A11W_-
Pg 12 2024 Idaho Annual Conservation Report �irMISTA

Program-by-Program Summaries
Commercial/Industrial Site-Specific Program
Description
Site-Specific (custom) incentives are available for many energy-efficiency projects that fall outside the parameters of
Prescriptive or Midstream programs.These incentives apply to first-year energy savings (not behavioral modifications)
and are offered for projects with measure-lives of 10 years or greater based on the simple payback of the individual
project.
Avista's account executives help customers identify energy-efficiency and incentive opportunities in Site-Specific
projects, including appliances, compressed air, industrial processes, non-prescriptive motors, shell, and lighting, with
most projects focusing on shell and lighting.
The program also includes a Pay for Performance track, designed to pay Avista's commercial/industrial customers
for implementing efficiency measures that are monitored at the meter level. Customers participating in this track
implement whole-building energy retrofits and receive a set incentive rate for measurable savings achieved over the
course of three years, with incentive payments made at the end of each year.
TABLE 14 - COMMERCIAL/INDUSTRIAL SITE-SPECIFIC PROGRAM METRICS
Site-Specific Program Summary-Electric
Participation,Savings,and Costs
Conservation Projects 18
Overall kWh Savings 5,185,350
Incentive Spend $ 1,162,477
Non-Incentive Utility Costs $ 457,068
Idaho Energy Efficiency Rider Spend $ 1,619,545
Site-Specific Program Summary-Natural Gas 2024
Participation,Savings,and Costs
Conservation Projects 3
Overall Therm Savings 4,818
Incentive Spend $ 18,928
Non-Incentive Utility Costs $ 5,269
Idaho Energy Efficiency Rider Spend $ 24,197
Program Activities
The electric Site-Specific Program showed strong performance in 2024, achieving 150 percent of its kWh savings
target of 3,456,295. This upward savings trend was likely influenced by the stabilization of interest rates for program
financing, as well as resolutions to supply chain disruptions that impacted the market from 2020-2023.
The natural gas program achieved 94 percent of planned therm savings. In addition to the savings claimed in the table
above,there are also five Pay for Performance projects currently contracted, all of which will be completed in future
years.
/III_-
4-krW STA 2024 Idaho Annual Conservation Report Pg 13

Program Changes
The program's longtime manager retired in 2024, and a new program manager was promoted internally. The Pay for
Performance track eliminated the minimum square-footage requirement, boosting participation by businesses with
smaller footprints.
Impact Evaluation
Tables 15 and 16 show reported and evaluated electric and natural gas energy savings for Avista's commercial/
industrial Site-Specific Program path for the year.
TABLE 15 - COMMERCIAL/INDUSTRIAL SITE-SPECIFIC PROGRAM IMPACT FINDINGS - ELECTRIC
F Program Type Reported Savings Evaluated Savings Realization Rate
A (kWh) I� (kWh)
Site-Specific 5,335,550 5,185,350 97%
TABLE 16 - COMMERCIAL/INDUSTRIAL SITE-SPECIFIC PROGRAM IMPACT FINDINGS - NATURAL GAS
-Evaluated Savings
Program Type Reported Savings Realization Rate
(Therms) F (Therms)
Site-Specific 5,408 4,818 89%
Plans for 2025
Avista plans to continue the Site-Specific Program in Idaho in 2025 and will assess the current measurement and
verification process to determine whether improvements are needed.The company will also continue the BPP and the
Trade Ally Bid Program therein.
A11W
Pg 14 2024 Idaho Annual Conservation Report III/VISTA

Commercial/Industrial Prescriptive Lighting Program
Description
The Prescriptive Lighting Program prompts commercial/industrial electric customers to increase the energy efficiency
of lighting equipment through direct financial incentives. This methodology indirectly supports the infrastructure
and inventory necessary to ensure that installation of high-efficiency equipment is a viable option for customers.
Program measures include retrofits from fluorescent lamps and fixtures, high-intensity discharge (HID), directional,and
incandescent can fixtures to more energy-efficient LED light sources and controls.
TABLE 17 - COMMERCIAL/INDUSTRIAL PRESCRIPTIVE LIGHTING PROGRAM METRICS
Prescriptive Lighting Program Summary-Electric
Participation,Savings,and Costs
Conservation Projects 417
Overall kWh Savings 6,888,637
Incentive Spend $ 2,297,810
Non-Incentive Utility Costs $ 524,393
Idaho Energy Efficiency Rider Spend $ 2,822,203
Program Activities
Business customers and trade allies faced inflation-related obstacles to energy-efficiency projects in 2024, and Avista
continued its generous incentive rate structure for this program. Originally implemented in July 2021, these robust
offerings help bridge the gap for large customers and trade allies as they navigate rising costs in labor and materials.
Since the launch of the Small Business Direct-Install Lighting Program in April 2023, overall project throughput and
savings have declined in the Prescriptive Lighting Program, as many customers are now directed to the enhanced
program when eligible. However, 2024 remained a busy year for the program, which achieved 208 percent of its
3,312,430 kWh target.
Program Changes
TABLE 18 - COMMERCIAL/INDUSTRIAL PRESCRIPTIVE LIGHTING PROGRAM CHANGES
Changes to Prescriptive Lighting Program Rebates
Exterior Lighting A —A
1
Replacement HID Lighting(Pole,Wallpack,or Canopy)
Requires at Least 4,288 Hours of Use per Year-Must Be DLC or ENERGY STAR-Rated
70-89W HID Fixture to<_25W LED Fixture or Lamp $ 85 $ 85
90-1 OOW HID Fixture to<_30W LED Fixture or Lamp $ 120 $ 120
150W HID Fixture to<_SOW LED Fixture or Lamp $ 180 $ 180
175W HID Fixture to<_I OOW LED Fixture or Lamp $ 180 $ 180
200W HID Fixture to<_140W LED Fixture or Lamp Site-Specific $ 120
250W HID Fixture to<_140W LED Fixture or Lamp $ 230 $ 230
320W HID Fixture to<_160W LED Fixture or Lamp $ 280 $ 280
400W HID Fixture to<_175W LED Fixture or Lamp $ 375 $ 375
575W HID Fixture to<_300W LED Fixture or Lamp $ 400 $ 400
/IIW__
�dFVgSTA 2024 Idaho Annual Conservation Report Pg 15

Changes to Prescriptive Lighting Program Rebates
750W HID Fixture to 5 300W LED Fixture or Lamp $ 750 $ 750
I OOOW HID Fixture to<_40OW LED Fixture or Lamp $ 930 $ 930
1500W HID Fixture to<—600W LED Fixture or Lamp $ 1,300 $ 1,300
New Construction Fixtures HID Lighting
Requires at Least 4,288 Hours of Use per Year-Must Be DLC or ENERGY STAR-Rated
175W Code HID Fixture to<—IOOW LED Fixture $ 150 $ 170
250W Code HID Fixture to<_140W LED Fixture $ 195 $ 225
320W Code HID Fixture to<—I60W LED Fixture $ 220 $ 250
Sign Lighting Retrofit-Requires at Least 4,288 Hours of Use per Year
T 12 to LED Sign Lighting—per Square Foot $ 13 $ 13
Controls
Exterior Networked Lighting Controls $ 85 $ 85
Interior Lighting
T12 to LED Sign Lighting-per Square Foot
Replacement Lamps-Must Be DLC or ENERGY STAR-Rated
T 12/T8 Fluorescent to!—13 W T8 Two Foot TLED $ 9 $ 9
T 12/T8 Fluorescent to<_ 17W T8 Three-Foot TLED $ 11 $ 11
T 12/T8 Fluorescent to<_23W T8 Four-Foot TLED $ 14 $ 14
T12/T8 Fluorescent to<_45W T8 Eight-Foot TLED $ 27 $ 27
T12/T8 Fluorescent to<_23W T8 U-Bend TLED $ 15 $ 15
T5 Fluorescent to<_ 18W TS Four-Foot TLED $ 17 $ 17
TSHO Fluorescent to<_29W TSHO Four-Foot TLED $ 35 $ 35
T8/T5 TLED to TLED(3-4W reduction) Site-Specific $ 3
T8/T5 TLED to TLED(>—SW reduction) $ 5 $ 7
Four-Pin Base CFL to Four-Pin Plug-in LED $ 18 $ 18
Replacement Fixtures-Must be DLC or ENERGY STAR-Rated
T 12/T8 to 5 40W 1 x4 LED Fixture $ 40 $ 40
T 12/T8 to 5 40W 2x2 LED Fixture $ 36 $ 40
T 12/T8 to<_60W 2X4 LED Fixture $ 60 $ 75
T12/T8 to<_90W Eight-Foot LED $ 85 $ 90
4-Lamp TSHO Fluorescent to<_ 135W LED $ 100 $ 120
6-Lamp TSHO Fluorescent to<_ 160W LED $ 210 $ 210
175W HID to<_75W LED Fixture or Lamp $ 145 $ 145
250W HID to<_140W LED Fixture or Lamp $ 265 $ 300
400W HID to 5 175W LED Fixture or Lamp $ 325 $ 325
I OOOW HID to 5 400W LED Fixture or Lamp $ 560 $ 600
>42W Incandescent Can to<_20W LED Fixture $ 20 $ 20
65W Incandescent to 5 IOW LED Fixture $ 45 $ 55
75-I OOW Incandescent Can to<_20W LED Fixture $ 60 $ 65
>_ ISOW Incandescent to<_30W LED Fixture $ 75 $ 85
Controls
Wall Switch Occupancy Sensor $ 17 $ 17
Ceiling or Fixture Mount Occupancy Sensor $ 75 $ 75
Networked Lighting Controls $ I50 $ I50
/IIN
Pg 16 2024 Idaho Annual Conservation Report A IVISTA'

Program Marketing
The success of the Prescriptive Lighting Program depends on clear communication to lighting supply houses,
distributors, electricians, and customers regarding incentive requirements and forms. The Avista website lists these
requirements and highlights opportunities for customers. In addition, the company's regionally based account
executives play an integral role in delivering program benefits to commercial/industrial customers. Any changes to the
program typically include 120 days of advance notice, allowing customers to submit applications for incentives under
old requirement/incentive levels if desired. This usually includes—at a minimum—website updates and direct emails to
trade allies.
Impact Evaluation
TABLE 19 - COMMERCIAL/INDUSTRIAL PRESCRIPTIVE LIGHTING PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Prescriptive Lighting 6,963,399 6,888,637 99%
Recommendations
Evaluators recommended using HVAC space-configuration information and interactive factors of HVAC effects when
calculating Prescriptive Lighting Program savings for interior spaces, as well as incorporating in-service rates specific to
lamp type.
Avista has acknowledged these recommendations and will consider them in the future, as negative values (such
as increased need for heating) often become more significant than positive values (like decreased need for air
conditioning). Including therms also puts an additional burden on the customer to report heating and cooling
information correctly.
Plans for 2025
With the more sophisticated measure-level detail in iEnergy, Avista has been able to update lighting measures
annually to reflect market conditions, adding new ones that were typically paid for through the Site-Specific Program.
Additionally, as a result of fewer small-business customers participating in this program, more refinements could
better align offerings with new customer demographics.
/llt
'.0-4VESTAW 2024 Idaho Annual Conservation Report Pg 17

Small Business Direct-Install Lighting Program
Description
Small-business customers covered by Rate Schedules I I and 12 are eligible through the Small Business Direct-Install
Lighting Program to receive benefits, including a free facility lighting assessment to identify potential upgrades;
installation of low- to no-cost energy-saving measures (lamps,fixtures, and controls); and informational handouts.
TABLE 20 - SMALL BUSINESS DIRECT-INSTALL LIGHTING PROGRAM METRICS
Small Business Direct-InstaR Lighting Program Summary-Electric
Participation,Savings,and Costs J
Conservation Projects 618
Overall kWh Savings 15,161,166
Incentive Spend $ 9,497,604
Non-Incentive Utility Costs $ 1,055,980
Idaho Energy Efficiency Rider Spend $ 10,553,584
Program Activities
The program was highly successful and far exceeded planned savings for the year. While much of the participation
has come from door-to-door marketing efforts among trade allies, co-branded promotion postcards mailed directly
to customers have also proven effective. Customer case studies posted on social media have been valuable in gaining
trust and engagement, often leading to word-of-mouth referrals to neighboring businesses. Lastly, the Avista website
has driven more customer traffic by highlighting the enhanced incentives and enrollment opportunity.
Program Changes
Beginning in May 2024, as the program saw a significant increase in project throughput, the third-party implementer
began site inspections on 5 percent of all projects.
Additionally, with the advancement of building code and lighting standards, along with ENERGY STAR discontinuing
the certification of non-recessed downlight products, the program eliminated incentives on screw-base lamps while
continuing to cover other ENERGY STAR-listed products.
Impact Evaluation
TABLE 21 - SMALL BUSINESS DIRECT-INSTALL LIGHTING PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Small Business Direct-Install Lighting 16,181,397 15,161,166 94%
A11W Pg 18 2024 Idaho Annual Conservation Report 4-4MISra

Recommendations
Evaluators recommended calculating savings for occupancy sensors using a different algorithm to avoid the slight
double counting of savings. Modifications to the calculation and incentive will be made on the first of the new year.
Plans for 2025
The company has taken several steps to re-focus the program on the intended small-business customer segment,
including removing municipalities, universities, schools, and hospitals from eligibility. And with numerous changes
to the Department of Energy's ENERGY STAR certification guidelines,the program no longer allows for certain non-
downlight specialty fixtures. Lastly, because the program team identified the control savings-calculation discrepancy
prior to the 2024 impact evaluation report, the changes to the calculation and incentive amount have already been
implemented.
Commercial/Industrial Prescriptive Non-Lighting Programs
This group of programs offers simple incentives for a wide variety of non-lighting measures. A description of each
offering follows, as does a recap of program activities.
Description/Program Activities
Green Motors Rewind—A program to restore a motor to its original efficiency through repair/rewind; commonly
called a "green rewind." The regional Green Motors Practices Group terminated its program in the fall of 2024.
Avista opted to bring the program in-house, using the same format to remain consistent for customers. Participating
service centers apply a$1-per-horsepower instant discount to the customer invoice,and Avista reimburses that rebate
when the appropriate paperwork is submitted. This is a small program with historically low throughput, but it is being
highlighted with the Power of Change campaign.
Commercial Grocer Program—A program designed to reduce energy use for customers with commercial
refrigeration equipment. National grocery chains submitted rebates for multiple stores (due to the uniformity of
refrigeration equipment in national chains, it is easier to retrofit and repair equipment across all stores). This is a small
program with low throughput, but it is being highlighted with the Power of Change campaign.
Commercial Prescriptive HVAC VFD Retrofit Program—A program that incentivizes application of a VFD on
commercial heating, ventilation, or air conditioning equipment served by Avista. The program pays $200 per
horsepower of the motor on which the VFD is installed. Installation verification is required before incentives are paid.
This program ended in 2024, and VFDs are now managed through the Site-Specific Program path.
Commercial Shell Program —Avista commercial customers using an Avista primary heat source are eligible for
incentives for bringing insulation up to code or better in wall, attic, or roof applications. The program was highlighted
in the Power of Change campaign, resulting in increased throughput.
�IIIV�STaW 2024 Idaho Annual Conservation Report Pg 19

TABLE 22 - COMMERCIAL/INDUSTRIAL PRESCRIPTIVE NON-LIGHTING PROGRAM METRICS
Prescriptive Non-Lighting Program Summary-Electric 11
Participation,Savings,and Costs
Conservation Projects 67
Overall kWh Savings 168,573
Incentive Spend $ 26,657
Non-Incentive Utility Costs $ 11,255
Idaho Energy Efficiency Rider Spend $ 37,912
Prescriptive Non-Lighting Program Summary-Natural Gas
Participation,Savings,and Costs 9
Conservation Projects 7
Overall Therm Savings 3,600
Incentive Spend $ 28,340
Non-Incentive Utility Costs $ 6,155
Idaho Energy Efficiency Rider Spend $ 34,495
Program Marketing
Avista account executives market these programs, as do external trade allies.All Prescriptive Non-Lighting programs
are also featured on Avista's website, where pages dedicated to business energy-savings are experiencing increased
traffic. In addition, program-specific flyers, a commercial offerings one-sheet, paid digital advertising, and customer
case-study campaigns were all used to build awareness about these opportunities.
Impact Evaluation
Electric:Table 23 shows the reported and evaluated electric energy savings for Avista's commercial/industrial
Prescriptive Non-Lighting Program path, as well as the realization rates between the evaluated and reported
savings for 2024. Overall the programs achieved a 125 percent realization rate.
TABLE 23 - COMMERCIAL/INDUSTRIAL PRESCRIPTIVE NON-LIGHTING PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type 11 Realization Rate
Commercial Grocer 37,199 37,199 100%
Commercial Prescriptive HVAC VFD Retrofit 81,760 1 15,1 1 1 141%
Commercial Shell 16,263 16,263 100%
Commercial/Inclustrial Total 135,222 168,573 125%
Natural GAS. Natural gas programs achieved a realization rate of 100 percent.
TABLE 24 - COMMERCIAL/INDUSTRIAL PRESCRIPTIVE NON-LIGHTING PROGRAM IMPACT FINDINGS - NATURAL GAS
Program Type Reported Savings Evaluated Savings Realization Rate
(Therms) (Therms)
Commercial Shell 3,600 3,600 100%
AIIW_
Pg 20 2024 Idaho Annual Conservation Report �IIn/�WTA

Recommendations
Evaluators recommended including facility heating and cooling equipment information within the Shell Program
tracking data.
Plans for 2025
Avista will reassess all program measures and incentive levels.
Midstream Program
Description
Avista's Midstream Program incentivizes the purchase of high-efficiency commercial HVAC, water-heating, and
foodservice products and helps ensure they are in stock when customers need them.The program works directly with
distributors, who influence equipment sales in the region.
TABLE 25 - COMMERCIAL/INDUSTRIAL MIDSTREAM PROGRAM METRICS
Midstream Program Summary- Electric
Participation,Savings,and Costs
Conservation Projects 105
Overall kWh Savings 172,150
Incentive Spend $ 84,815
Non-Incentive Utility Costs i$ !Mll J4,21Idaho Energy Efficiency Rider Spend
Midstream Program Summary- Natural Gas
Conservation Projects 130
Overall Therm Savings 24,769
Incentive Spend $ 144,028
Non-Incentive Utility Costs $ 32,933
Idaho Energy Efficiency Rider Spend $ 176,961
Program Activities
Throughout 2024 Avista worked to address the Midstream Program's low realization rates in 2023. In consultation
with evaluators, the program implementer reviewed and updated savings assumptions and methodologies across
all measures.As a result, realization rates for the commercial program improved across both electric and natural gas
measures in 2024.
/IIW_
�dFVFSTA' 2024 Idaho Annual Conservation Report Pg 21

Program Changes
Beginning in 2024, residential new construction Tier I heat pumps were no longer eligible for incentives, and
commercial furnaces changed to a per-unit incentive structure. New commercial foodservice measures eligible for
discount include:
Conveyor toasters
Electric holding bins
• Natural gas and electric cooktops
• Rotisseries
• Soup wells
• Steam tables
Throughout 2024,the program was open to any interested distributor, and a handful of new distributors joined.
Impact Evaluation
TABLE 26 - COMMERCIAL/INDUSTRIAL MIDSTREAM PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Midstream 179,583 172,150 96%
TABLE 27 - COMMERCIAL/INDUSTRIAL MIDSTREAM PROGRAM IMPACT FINDINGS - NATURAL GAS
Program Type
Midstream 26,804 24,769 92%
Recommendations
The evaluators found that all measures' claimed savings were calculated based on assumed average equipment sizing,
whereas verified savings calculations were carried out using standard engineering algorithms. Although relative
magnitudes of savings per project generally aligned with algorithm-based results, the evaluators recommended the
program implementers adjust assumed average sizing to better reflect program participants' purchasing behaviors.
Avista acknowledges the recommendations and is working with the implementor and evaluators to coordinate the
appropriate midstream design for evaluation.
Plans for 2025
During 2025, Avista will add packaged terminal heat pumps, PEI (Pump Energy Index) pumps, and heat pumps for
space-constrained installations like manufactured homes. Quarterly market share reports to distributors will continue
as a means of promoting healthy competition within the market.
,A°! -
Pg 22 2024 Idaho Annual Conservation Report ,AiiVJFSTA

Building Operator Certification Program
Description
This national training and certification program helps participants develop skills in commercial building operation,
with an emphasis on no-cost and low-cost solutions. Competency is demonstrated through project work involving the
participants' own buildings and equipment.
TABLE 28 - BUILDING OPERATOR CERTIFICATION PROGRAM METRICS
OperatorBuilding
Participation,Savings,and Costs
Conservation Projects I
Overall kWh Savings 1 19,000
Incentive Spend $ —
Non-Incentive Utility Costs $ 3,628
Idaho Energy Efficiency Rider Spend $ 3,628
Program Activities
Avista partnered with Building Potential (formerly the Northwest Energy Efficiency Council or NEEC) to bring a
Building Operator Certification (BOC)training course to the Inland Northwest.Avista also offered a discount on the
course for customers managing commercial buildings.
Plans for 2025
Avista plans to actively recruit participants for the in-person Level I course in Spokane with the assistance of the
account executive and community relations teams. Avista will also continue to share information about upcoming
virtual and in-person BOC courses with customers.Avista energy efficiency staff plan to regularly attend BOC courses
to share energy-efficiency program information with Avista customers who participate in BOC courses.
/IIt_
�11/V1STA 2024 Idaho Annual Conservation Report Pg 23

RESIDENTIAL SECTOR
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RESIDENTIAL SECTOR
Overview
Avista offers a wide variety of programs encouraging residential customers to save energy while living more
comfortably in their homes. Over $1.5 million in rebates and direct benefits went to Idaho residential customers in
2024, offsetting costs and enabling customers to make desired upgrades. The combined energy savings achieved for
all programs within the residential portfolio were 2,390,778 kWh and 185,712 therms.
Portfolio Performance
The electric portfolio's achievement of 1 17 percent of 2024 planned savings reflects the Midstream Program reaching
six-and-a-half times the expected savings, accounting for 79 percent of total savings. The Appliances Program also
over-performed at 145 percent of planned savings. 2024 was the first year that the Home Energy Audit Program was
evaluated for savings, and while savings were less than expected, the evaluation was informative. The Fuel-Efficiency
and Shell programs also had lower-than-expected savings in 2024.
Table 29 shows planned savings assigned to Avista's residential programs for the year, as well as verified savings and
the percentage of planned savings achieved.
TABLE 29 - RESIDENTIAL PROGRAMS VERIFIED VS PLANNED SAVINGS - ELECTRIC
(kWh) (kWh) Planned Savings
Planned Savings Verified Savings Percentage of
Midstream 293,307 1,891,168 645%
Shell 1,032,269 214,110 21%
Home Energy Audit 112,181 9,418 8%
ENERGY STAR/NEEM Manufactured Housing — 77,951 -
Appliances 65,395 94,924 145%
Fuel-Efficiency 539,240 103,207 19%
Residential Total 2,042,392 2,390,778 1 17%
/III
,,iAiiV1STA 2024 Idaho Annual Conservation Report Pg 25

The natural gas segment of the residential portfolio achieved 64 percent of planned savings for 2024.
The following shows the percentage of residential evaluated savings provided by each program:
• The Midstream Program accounted for 78 percent of residential natural gas savings.
Prescriptive programs accounted for the remaining 32 percent of residential natural gas savings.
Table 30 shows planned savings assigned to Avista's residential natural gas programs for 2024, as well as verified
savings and percentage of planned savings achieved.
TABLE 30 - RESIDENTIAL PROGRAMS VERIFIED VS PLANNED SAVINGS - NATURAL GAS
Program Planned Savings Verified Savings Percentage 01--
gs
Ift (Therms) (Therms) Planned Savin
Midstream 180,942 144,315 80%
Prescriptive 109,259 41,397 38%
Residential Total 290,201 64%
Impact Evaluation
The residential sector saw higher-than-expected realization rates in 2024, due primarily to high realization rates for
Midstream and Shell programs for both natural gas and electric measures. Natural gas appliance measures also had
higher than expected realization rates (see program-by-program summaries as well as Appendices A and B, Electric
and Natural Gas Impact Evaluation Reports).
• Electric:Verified savings of 2,390,778 kWh, resulting in a realization rate of 118 percent.
• Natural Gas:Verified savings of 185,712 therms, resulting in a realization rate of 226 percent.
AIIW- T/�
Pg 26 2024 Idaho Annual Conservation Report �4V1STAff

Cost-Effectiveness
The tables below show residential sector cost-effectiveness results by fuel type.
TABLE 31 - RESIDENTIAL COST-EFFECTIVENESS RESULTS - ELECTRIC
Cost-Effectiveness Test Benefits Costs Benefit/Cost Ratio
UCT $ 4,339,129 $ 1,146,640 3.78
TRC $ 4,339,129 $ 1,855,502 2.34
PCT $ 5,007,744 $ 1,377,477 3.64
RIM $ 4,339,129 $ 1,314,988 3.30
TABLE 32 - RESIDENTIAL COST-EFFECTIVENESS RESULTS - NATURAL GAS
UCT $ 1,799,871 $ 1,537,790 1.17
TRC $ 1,799,871 $ 1,151,918 1.56
PCT $ 3,002,867 $ 579,530 5.18
RIM $ 1,799,871 $ 1,646,082 1.09
Marketing
Meeting customers where they are, with information that's valuable to them, drives Avista's energy-efficiency
marketing strategies to increase awareness and engagement. Both markedly increased in 2024 through exposure on
owned channels, including web pages, bill inserts, print and electronic newsletters, email, and social media. Additional
audiences were reached through expanded print tactics and digital display and search ads.
Education was a focus throughout the year, with "summer cooling" and "winter bill" campaigns promoting easy
energy-saving tips on social media, in Avista's newsletter, in digital and print advertising, and via direct email outreach.
Digital ads and website content were translated into Spanish.
Digital and search ad campaigns promoting energy-efficiency rebate programs ran throughout 2024. Ad materials
were refreshed and optimized through A/B testing, utilizing new imagery and a clarified call-to-action button.
Energy-efficiency awareness also built through messaging in Avista sponsorship activities. Local sporting event
programs included program ads and even energy-saving games for kids. Radio advertisements helped share DIY tips
on saving energy.
/11[
,,iA-dFW.5TA 2024 Idaho Annual Conservation Report Pg 27

At Home with Lisa
Many Avista customers live in older, energy-inefficient homes. Between 2020 and late 2024,the company partnered
with Lisa, an Avista customer who bought her 1910 house because she loved its old-world character—then quickly
discovered it wasn't very energy-friendly. Lisa wrote weekly features sharing her experience with do-it-yourself projects
to improve her energy use and comfort. Avista expanded the "At Home with Lisa" series in 2022 to include a digital
campaign using static ads and short videos. In the videos, Lisa walks viewers through DIY projects, everything from
thermostat control to mail slot fixes, hot water heater wrap to window plastic, door sweeps to insulated drapes. Two
final "Lisa" videos were completed in early 2024, focusing on the benefits of the Home Energy Audit Program and
how it helped drive her decision to upgrade her windows and doors using Avista's energy-efficiency rebates. The
"Lisa" series continues to be shared through Avista's owned channels, website, and messaging through direct mail
and social media.
Power of Change
Building on the success of the "At Home with Lisa" series, Avista's Power of Change campaign included messages for
residential customers in 2024. Positioning energy efficiency as an entry point to the broader energy conversation, the
campaign offers tips on low-cost ways to save energy that are delivered in a light-hearted and humorous tone. When
relevant, residential programs are also promoted.
Ads ran on Meta, X, Linkedln, TikTok, and YouTube, in addition to digital display and streaming, and messaging was
included in sponsorship activations for local sporting events. Ads ran in six-week phases, with a total of six ads per
phase.
FIGURE 3 - RESIDENTIAL POWER OF CHANGE ADS
THE POWER OF CHA
S
Pg 28 2024 Idaho Annual Conservation Report GIII��sra

Program-by-Program Summaries
Midstream Program
Description
Avista's Midstream Program incentivizes the purchase of high-efficiency residential HVAC and water-heating systems
and works to ensure these products are always in stock for customers.The program works directly with distributors,
who influence equipment sales in the region.
TABLE 33 - RESIDENTIAL MIDSTREAM PROGRAM METRICS
Midstream Program Summary- Electric
Participation,Savings,and Costs
Conservation Projects 897
Overall kWh Savings 1,891,168
Incentive Spend $ 400,000
Non-Incentive Utility Costs $ 297,996
Idaho Energy Efficiency Rider Spend $ 697,996
------9W Midstream Program Summary- Natural Gas
Participation,Savings,and Costs
Conservation Projects 1,640
Overall Therm Savings 144,315
Incentive Spend $ 709,650
Non-Incentive Utility Costs $ 249,126
Idaho Energy Efficiency Rider Spend $ 958,776
Program Activities
The electric program had a very strong year, achieving 645 percent of the kWh savings target of 293,307. The natural
gas program achieved 80 percent of planned savings of 180,942 therms.
Program Changes
Beginning in 2024, residential new construction Tier I heat pumps were no longer eligible for incentives. Throughout
2024, the program was open to any interested distributor, and a handful of new distributors joined.
'All[
,ir-drVISTA 2024 Idaho Annual Conservation Report Pg 29

Impact Evaluation
TABLE 34 - RESIDENTIAL MIDSTREAM PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Midstream 1,492,479 1,891,167 126.7%
TABLE 35 - RESIDENTIAL MIDSTREAM PROGRAM IMPACT FINDINGS - NATURAL GAS
Program Type Reported Savings Evaluated Savings Realization Rate
I (Therms) (Therms) I
Midstream S I,706.71 144,314.62 279.10%
As mentioned on page 5 of this report, evaluation of residential furnaces in 2024 resulted in significantly higher
savings per measure than in 2023. The reported savings in the tables above reflect the lower savings assumption in
the 2023 impact evaluation, which, after billing analysis, resulted in a much higher-than-expected realization rate for
the program, because furnaces account for the vast majority of savings therein.
Recommendations
Evaluators recommended Avista estimate natural gas savings for furnace measures based on billing analysis results.
The natural gas furnace billing analysis yielded annual savings of 90 therms, for a 298% realization rate for the
measure. According to the evaluators, "furnace installation by Avista customers in Idaho seems to be associated with
substantially higher natural gas savings than reported by the RTF Residential Gas Furnace UES workbook.To maximize
the accuracy of reported savings, future ex-ante savings estimates should likely be based on billing analysis results
instead of deemed savings."
Evaluators also recommended that the Midstream Program continue incorporating RTF baselines for all non-furnace
measures.
Avista acknowledges and agrees with the recommendations and is working with the implementor and evaluators to
implement these recommendations.
Plans for 2025
During 2025, Avista will add packaged terminal heat pumps, PEI pumps, and heat pumps for space-constrained
installations like manufactured homes. Quarterly market share reports to distributors will continue as a means of
promoting healthy competition within the market.
A11W _
Pg 30 2024 Idaho Annual Conservation Report 04MISTA'

Residential Shell Program
Description
Avista encourages residential customers to improve the building envelope of their homes by adding insulation and
storm windows and/or upgrading existing windows and exterior doors. For insulation projects, required contractor
documentation includes an invoice and verification of the space's square footage insulated and both pre- and post-
installation R-values.
TABLE 36 - RESIDENTIAL SHELL PROGRAM METRICS
Shell Program Summary-Electric
Participation,Savings,and Costs
Conservation Projects 933
Overall kWh Savings 214,110
Incentive Spend $ 161,589
Non-Incentive Utility Costs $ 1 14,518
Idaho Energy Efficiency Rider Spend $ 276,107
Shell Program Summary-Natural Gas
Participation,Savings,and Costs
Conservation Projects 520
Overall Therm Savings 21,430
Incentive Spend $ 430,006
Non-Incentive Utility Costs $ 63,438
Idaho Energy Efficiency Rider Spend $ 493,443
Program Activities
In 2024, insulation contractors employed aggressive marketing and Communication tactics to encourage participation
in the residential Shell Program.This led some customers to contact Avista with concerns about the quality of work. In
response,Avista hired a third-party inspector to conduct random insulation inspections.This quality control project will
be completed in 2025.
Impact Evaluation
TABLE 37 - RESIDENTIAL SHELL PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Shell 189,092 214,110 1 13.23%
TABLE 38 - RESIDENTIAL SHELL PROGRAM IMPACT FINDINGS - NATURAL GAS
Program Type Reported Savings Evaluated Savings Realization Rate
(Therms) (Therms)
Shell 18,414 21,420 1 16.38%
/IIX
'IIIVISTA 2024 Idaho Annual Conservation Report Pg 31

Recommendations
• The evaluators found that verified savings from attic insulation, wall insulation, and window upgrades
displayed low realization rates at the project level, primarily due to granular differences between RTF and
Avista TRM prescriptive savings values. The RTF differentiates savings by heating type, R-value, and climate
zone, while the TRM provides more generalized estimates. With appropriate weighting, such generalized
savings estimates can be valid; however, several Shell Program savings values presented in the TRM don't
align perfectly with characteristics of the average participating home. The evaluators recommended Avista
update the TRM value to reflect a more accurate weighted average.
• The evaluators found some project documentation lacking, pointing to discrepancies in unit quantities,
insufficient verification of square footage and R-values, and questionable claims about savings values. They
recommended Avista verify that each project meets efficiency requirements through documentation provided
in the application and request additional information if needed. The evaluators also recommended Avista
conduct measure-level verification to ensure proper fuels are being claimed in the tracking datasets.
• Further, the evaluators recommended Avista assign window-measure savings by window square footage
rather than unit quantity, and that expected heating type be incorporated into UES values (estimates of
energy savings for a single unit of an installed energy-efficiency measure) to align with RTF projections.
Additionally, they recommended that program managers determine if an applicant is an Avista electric and/or
natural gas customer before providing an incentive for dual fuel.
The company will consider these recommendations as it plans for the next program year. For insulation measures,the
company will take these recommendations into account as it develops and implements a new insulation program.
Plans for 2025
In 2025,Avista plans to replace insulation measures under the current Shell Program with a direct-install model, in which
a third party will oversee a closed network of contractors. The program, which is called the Home Insulation Program
(HIP)will be available only to electric customers in Idaho.
'Anw
Pg 32 2024 Idaho Annual Conservation Report ,AiiVJFSTA

Residential Home Energy Audit Program
Description
The Home Energy Audit Program offers customers a personalized in-home audit to identify opportunities for energy-
efficient upgrades. After the audit, the customer receives a written Home Performance Report detailing the auditors'
recommendations, estimated project costs, potential energy savings, directions for installation of some energy-saving
measures, and handouts with follow-up information.
TABLE 39 - RESIDENTIAL HOME ENERGY AUDIT PROGRAM METRICS
Home Energy Audit Program Summary-Electric
Participation,Savings,and Costs
Conservation Projects 120
Overall kWh Savings 9,418
Incentive Spend $ —
Non-Incentive Utility Costs $ 120
Idaho Energy Efficiency Rider Spend $ 120
ne Energy Audit Program Summary-Natural Gas 2024
Participation,Savings,and Costs
Conservation Projects 263
Overall Therm Savings —
Incentive Spend $ —
Non-Incentive Utility Costs $ —
Idaho Energy Efficiency Rider Spend $ —
Program Activities
This program remained extremely popular in 2024, resulting in a lengthy waiting list. The program currently conducts
approximately 40 audits per week, roughly 25 percent more than in previous years. Efforts to grow customer
awareness and participation included several communication tactics: A new handout was developed for in-person
outreach events; a second promotional video was created, highlighting the benefits of the program through the "At
Home with Lisa"series; and all residential customers received a bill insert in September, leading up to National Energy
Awareness Month.
Program information was also highlighted in Avista's customer newsletters, which accompany paper bills or are sent
electronically to those with paperless billing. In addition,three direct emails were sent to households with higher-than-
average energy usage.
While savings were identified for homes with electric heat, evaluators found no savings for natural gas-heated homes.
However, the program still significantly benefits customers by helping them identify opportunities to pursue efficiency
upgrades.
Allt
,ir-IuVISTA 2024 Idaho Annual Conservation Report Pg 33

Impact Evaluation
TABLE 40 - RESIDENTIAL HOME ENERGY AUDIT PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Home Energy Audit NIA 9,418 NIA
Plans for 2025
Avista plans to continue the Home Energy Audit Program in 2025.
Residential ENERGY STAR/NEEM Manufactured Housing Program
Description
Any Idaho residential electric or natural gas customers who purchase a new ENERGY STAR manufactured home (as
certified by the Northwest Energy-Efficient Manufactured Housing Program or NEEM) with Avista covering their space
and water heating are eligible for the rebate.
TABLE 41 - RESIDENTIAL ENERGY STAR/NEEM MANUFACTURED HOUSING PROGRAM METRICS
ENERGY STAR/NEEM Manufactured Housing Program Summary-Electric
Participation,Savings,and Costs
Conservation Projects 26
Overall kWh Savings 77,951
Incentive Spend $ 26,000
Non-Incentive Utility Costs "$ 68,628
Idaho Energy Efficiency Rider Spend
ENERGY STAR/NEEM Manufactured Housing Program Summary- Natural Gas
Participation,Savings,and Costs
Conservation Projects —
Overall Therm Savings —
Incentive Spend $ —
Non-Incentive Utility Costs $ —
Idaho Energy Efficiency Rider Spend $ —
Program Activities
All homes incentivized through this program in 2024 utilized electric heat, an interesting trend that may be driven by
the fact that a large majority of participating homes were in rural areas without access to natural gas infrastructure.
A11W
Pg 34 2024 Idaho Annual Conservation Report III/VESTA

Impact Evaluation
TABLE 42 - RESIDENTIAL ENERGY STAR/NEEM MANUFACTURED HOUSING PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
ENERGY STAR/NEEM Manufactured Housing 85,018 77,951 91.69%
Recommendations
The evaluators found that realization rates differed from 100 percent due to the application of RTF-designated heating
and cooling zones (geographic areas within the region defined by their climate characteristics to model energy
consumption),which Avista's TRM lacks.They recommended updating the measure savings database to match the
primary heating type for dual-fuel households and heating/cooling zones reflected in the RTF workbooks.
Avista will consider this recommendation and may make changes accordingly.
Plans for 2025
Avista plans to continue the ENERGY STAR/NEEM Manufactured Housing Program in 2025.
Residential Appliances Program
Description
Avista has long offered incentives for high-efficiency appliances such as residential washers, dryers, and refrigerators
through point-of-sale programs, Prescriptive paths, and other avenues. Prescriptive offerings include rebates for
ENERGY STAR-certified appliances, including:
front-load and top-load washers
electric and natural gas dryers
refrigerators/freezers
freezers
/llt__ TA
�Iliv�sr�© 2024 Idaho Annual Conservation Report Pg 35

TABLE 43 - RESIDENTIAL APPLIANCES PROGRAM METRICS
Appliances Program Summary-Electric 2024
Participation,Savings,and Costs
Conservation Projects 606
Overall kWh Savings 94,924
Incentive Spend $ 50,726
Non-Incentive Utility Costs $ 5,755
Idaho Energy Efficiency Rider Spend $ 56,480
if Appliances Program Summary-Natural Gas 0
Participation,Savings,and Costs
Conservation Projects 509
Overall Therm Savings 19,968
Incentive Spend $ 63,340
Non-Incentive Utility Costs $ 22,231
Idaho Energy Efficiency Rider Spend $ 85,571
FIGURE 4 - RESIDENTIAL APPLIANCES PROGRAM FLYER
91V15TA
it
Save energy and money
with Avista rebates.
Program Activities
The electric program achieved 145 percent of its savings goal of 65,395 kWh in 2024. The natural gas program
performed lower than expected, achieving around 39 percent of the program goal.
/IIW__
Pg 36 2024 Idaho Annual Conservation Report ,Air JVSTA

Impact Evaluation
TABLE 44 - RESIDENTIAL APPLIANCES PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Appliances 150,143 94,924 63.22%
TABLE 45 - RESIDENTIAL APPLIANCES PROGRAM IMPACT FINDINGS - NATURAL GAS
Program Type Reported Savings Evaluated Savings Realization Rate
Appliances 11,974 19,968 166.77%
Recommendations
• In the Appliances Program, one sampled smart-thermostat rebate included equipment that did not meet
specifications to receive verified savings through the RTF workbooks, from which the Avista TRM savings
values are drawn. The evaluators recommended providing a qualified product list for customers to ensure
purchased smart thermostats meet program requirements. In addition,the evaluators recommended Avista
review program documentation to verify qualifications after rebates are submitted.
• The evaluators recommended Avista update the clothes dryer TRM value to correctly assign 1.60 therm
savings for the measure, as reflected in the RTF (currently, the Avista TRM reflects 2.72 therms/unit).
Additionally,the evaluators recommended Avista update the front-load clothes washer TRM value to correctly
convert 1 19.99 kWh/unit to 2.40 therms/unit (currently, the Avista TRM reflects 6.03 therms/unit).
• The evaluators note that the RTF defines an annual savings of 1 1.7 therms for all natural gas smart-
thermostat measure specifications defined in the Connected Thermostats RTF workbook. Although this
finding did not impact the realization rate of the program in 2024 (due to statistically significant savings
identified for smart thermostats through the billing analysis method),the evaluators recommended Avista
update the assumed claimed savings values in the TRM to avoid discrepancies in future smart-thermostat
savings calculations.
• The evaluators also found one sampled smart-thermostat model that did not meet the minimum RTF
qualifications for savings, although Avista had assigned the maximum savings value to that project. The
evaluators recommended Avista verify each smart-thermostat model meets the RTF requirements for regional
savings compared to the market practice baseline, or provide a list of qualified products for customers to
select from when participating in this program.
Plans for 2025
Thermostat measures will be discontinued in 2025. The company will consider updating the TRM for clothes dryers, as
described in the evaluator's recommendations.
/Ilw
,d-4uVffSTA 2024 Idaho Annual Conservation Report Pg 37

Residential Fuel-Efficiency Program
Description
Avista's residential rebate program provides a variety of options to assist customers with multiple energy-efficiency
improvements for the home, including space and water-heating systems, the building shell, and appliances.
Idaho residential electric customers (Schedule 1) who heat their homes with Avista electricity may be eligible for a
rebate to convert their electric straight-resistance space heating to a natural gas system. Annual energy use in the
home pre-upgrade must show 4,000 kWh or more (and less than 340 therms if natural gas is also available) of
heating use. The supporting documentation required for participation includes, but may not be limited to, copies of
project invoices and AHRI (Air-Conditioning, Heating, and Refrigeration Institute) certification.
The rebate is paid to the customer after the measure has been installed and documentation has been received.
Energy-efficiency marketing efforts build awareness of opportunities in the home and drive customers to the website
for rebate information. Vendors generate participation using the Avista rebate as a sales tool for their services.
TABLE 46 - RESIDENTIAL FUEL-EFFICIENCY PROGRAM METRICS
Fuel-Efficiency Program Summary-Electric
Participation,Savings,and Costs L
Conservation Projects I5
Overall kWh Savings 103,2 77
Incentive Spend $ 30,300
Non-Incentive Utility Costs $ 17,008
Idaho Energy Efficiency Rider Spend $ 47,308
Program Activities
The electric program produced saving of 103,207 kWh in 2024, which is 4 percent of the overall residential impact.
Impact Evaluation
TABLE 47 - RESIDENTIAL FUEL-EFFICIENCY PROGRAM IMPACT FINDINGS - ELECTRIC
Program Type Reported Savings Evaluated Savings Realization Rate
Fuel-Efficiency 105,612 103,207 97.72%
/IIm__
Pg 38 2024 Idaho Annual Conservation Report ,Air JF.5TA'

Recommendations
The evaluators recommended updating the Avista tracking database to capture previous heating types for conversion
measures and requiring the rebate application to include the home's type, previous heating type, and existing cooling
type. Furthermore, Avista should review the AHRI annual fuel utilization efficiency (AFUE) reported values to make
sure the equipment qualifies for savings, and enforce required document submission for all rebates (such as the AHRI
certification or full model number).
Plans for 2025
Avista will consider making changes to this program as suggested by program evaluators.
,Allw
�IIIVLSTA© 2024 Idaho Annual Conservation Report Pg 39

LOW-INCOME SECTOR
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LOW-INCOME SECTOR
Program-by-Program Summaries
Low-Income Program
Description
Avista partners with a CAP agency to deliver energy-efficiency programs to low-income residents in 10 counties within
the company's Idaho service territory. The CAP agency has the infrastructure in place to income-qualify customers, as
well as provide them access to a variety of funding sources for efficiency improvements in their homes. The agency
serving Avista's Idaho territory receives an annual funding amount of$875,000, with an additional $75,000 allocated
for conservation and outreach efforts.
The CAP agency has discretion in spending contracted program dollars on either electric or natural gas efficiency
measures, depending on individual customer need. The home must demonstrate a minimum level of annual energy
use of Avista electricity or natural gas for space-heating purposes to be eligible for improvements to the residential
shell (e.g. insulation, windows, and roof). For conversions from electric resistive heat to a heat pump or to a natural
gas furnace, an annual use of 4,000 kWh is required. Customers with natural gas as their main heating source
must demonstrate a baseline usage of at least 340 therms. The annual funding allocation includes a 15 percent
reimbursement for both administrative and program support costs. The agency may also choose to allocate up to 15
percent of its funding for home repairs as well as other health and safety improvements.
TABLE 48 - LOW-INCOME PROGRAM METRICS
Participation,Savings,and Costs
Low-income Program Summary-Electric
Conservation Projects 64
Overall kWh Savings 64,878
Incentive Spend $ 213,700
Non-Incentive Utility Costs $ 13,807
Idaho Energy Efficiency Rider Spend $ 227,507
Low-income Program Summary-Natural Gas
Participation,Savings,and Costs
Conservation Projects 39
Overall Therm Savings 1,380
Incentive Spend $ 186,030
Non-Incentive Utility Costs $ 2,715
Idaho Energy Efficiency Rider Spend $ 188,744
In 2024 the Low-Income Program served 20 electric and 19 natural gas customers. Program participation is quantified
in the number of installed units or square feet of installed insulation or windows.
/lIN,,04FV1STA 2024 Idaho Annual Conservation Report Pg 41

Program Activities
TABLE 49 - LOW-INCOME PROGRAM REPORTED SAVINGS
Planned Savings Verified Savings Percentage of
I Planned Savings
"Electric ) 121,549 64,878 53%
Natural Gas(Therm) 496 1,380 278%
Avista continued to reimburse CAP agencies for 100 percent of the cost of installing most energy-efficiency measures
defined on the approved measure list(see Table 50). The program achieved very high natural gas savings in 2024,
especially when compared to other natural gas programs. The factors contributing to the natural gas program's
success are unclear, because benefits are provided on a first-come, first-served basis, and heating fuel type is not a
factor in prioritizing weatherization services. Achievements across the electric and natural gas sectors can therefore
vary.
TABLE 50 LOW-INCOME PROGRAM APPROVED MEASURE LIST
Electric Efficiency Measures Natural Gas Efficiency Measures
Air infiltration
Attic insulation
Doors—ENERGY STAR-rated
Duct insulation
Boiler(96%AFUE)
Duct sealing
Doors—ENERGY STAR-rated
Electric to air-source heat pump(9 HSPF)
Electric to ductless heat pump(10 HSPF) Furnace ate AFUE)
Water heater
Electric to natural gas furnace conversion (storage)<55 gallons.65 EF
Floor insulation Water heater(tankless).82 EF
LED lamps Windows—ENERGY STAR-rated,U-factor.30 or less
Refrigerator—ENERGY STAR-rated
Wall insulation
Windows—ENERGY STAR-rated,U-factor.30 or less
The CAP agency may receive partial reimbursement for installation of measures that are on the acceptable measures
list but did not meet the cost-effectiveness test. The amount of reimbursement is equal to the avoided cost-energy
value of the improvement. This approach focuses the agency toward installing measures with the greatest cost-
effectiveness from the utility's perspective. To allow for additional flexibility, the agency may use dollars allocated for
health and safety to fully fund the cost of these measures.
TABLE 51 - LOW-INCOME PROGRAM QUALIFIED REBATE MEASURE LIST
r Electric Efficiency Measures Natural Gas Efficiency Measures
Air infiltration:$73.44
Attic insulation:$1.25/sq ft
Air-source heat pump replacement(9 HSPF):$636.45 Door sweep:$1/sq ft
Door sweep:$3 Duct insulation: $.096/sq it
Electric to natural gas space and water heat:$3,211.14 Duct sealing: $157.82
Electric to natural gas hot water heat:$376.35 Floor insulation:$.97/sq ft
Heat pump water heat(Tier 2-3 any size):$281.10 Smart thermostat:$75
Storm windows:$1/sq ft
Wall insulation:$.7S/sq ft
A11W Pg 42 2024 Idaho Annual Conservation Report ,AiiVgSTA

Program Changes
A new program manager was hired in November 2024.
Customer Outreach
Customers who participate in the Low-Income Weatherization Program are often referred through the partner
agency's energy-assistance program. Avista also provides a handful of referrals each year from its internal
departments, including energy efficiency and customer service, as well as its Customer Assistance Referral and
Evaluation Services(CARES) Program,which provides support for disabled,elderly,and low-income customers,or
customers experiencing hardships related to employment, health, or finances.
Other referrals come from Avista's outreach events.The community and economic vitality department collaborates
with energy-efficiency efforts to educate and support low-income customers, seniors, veterans, and individuals
with disabilities. The outreach team engages these populations through workshops, community events, and mobile
outreach, distributing materials focused on low- and no-cost efficiency and conservation. Key outreach strategies
include:
Workshops: Hands-on coaching on energy conservation for senior and low-income customers.
Mobile outreach:Avista energy resource vans provide tips on managing energy use, bill payment options,
and community resources.
• Ceneral outreach: Information and resources at events (such as resource fairs) and through partnerships
that reach the target populations. General outreach also includes outlining bill payment options and
assistance resources in senior and low-income publications.
In Q4 2024, Avista's outreach efforts in Idaho —led by a CAP agency in Lewiston —continued to grow in both reach
and impact. The agency's conservation education specialist dedicated approximately 280 hours to engaging with
Avista customers through a combination of phone calls, emails,flyers, and in-person conversations at the CAP office.
Despite winter weather challenges, outreach efforts remained strong:
1,224 community members were reached through printed and digital materials, including flyers, brochures,
and informational videos focused on low-cost weatherization tips and energy-saving behaviors.
• The CAP agency participated in a presentation at Lewis-Clark Early Childhood Development in Lewiston,
engaging with approximately 60 attendees —primarily Head Start parents —on topics such as window films,
door strips, and other energy-saving services.
One-on-one education was provided to 23 individuals, offering personalized conservation advice and
distributing Conservation Education (ConEd) kits.
To improve efficiency and customer experience,the CAP agency pre-assembled ConEd kits that included an
instruction sheet and estimated savings for each item. This change allowed more time for meaningful conversations
and ensured that even when staff were unavailable, customers still received valuable education.
Through this experience,the agency observed that weatherization items like window films and door strips were more
impactful for community members than water-saving tools. Moving forward, weatherization kits will be prioritized
for in-person events, while water-saving items will be distributed at mobile pantries where educational interaction is
limited.
'All[_
�II�VISTA 2024 Idaho Annual Conservation Report Pg 43

FIGURE 5 - LOW-INCOME PROGRAM WEATHERIZATION FLYER
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Pg 44 2024 Idaho Annual Conservation Report III��sra

Cost-Effectiveness
Tables 52 and 53 show the low-income sector cost-effectiveness results by fuel type.
TABLE 52 - LOW-INCOME PROGRAM COST-EFFECTIVENESS RESULTS - ELECTRIC
Cost-Effectiveness Test
TRC $ 125,328 $ 248,467 0.50
UCT $ 125,328 $ 227,507 0.55
PCT $ 339,028 $ 234,660 1.44
RIM $ 125,328 $ 232,075 0.54
PCT is not appropriate to apply to Low-Income benefits and costs.These totals include Low-Income totals aggregated with residential and commercial totals.
TABLE 53 - LOW-INCOME PROGRAM COST-EFFECTIVENESS RESULTS - NATURAL GAS
Cost-Effectiveness Test
TRC $ 14,594 $ 208,059 0.07
UCT $ 14,594 $ 188,744 0.08
PCT $ 200,624 $ 205,345 0.98
RIM $ 14,594 $ 189,549 0.08
* PCT is not appropriate to apply to Low-Income benefits and costs.These totals include Low-Income totals aggregated with residential and commercial totals.
Impact Evaluation
Low-Income programs were not evaluated in 2024, in keeping with the EM&V plan for program years 2024 and
2025.
Plans for 2025
Avista will continue to implement weatherization measures in Idaho through its partnership with the Lewiston CAP
agency—the sole Community Action Agency operating in Avista's service territory. As part of the eligibility review
process, the agency will identify customers with high energy burdens, and Avista will support this effort by providing
relevant data and coordinating outreach activities.
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'.0-4VISTAff 2024 Idaho Annual Conservation Report Pg 45

PILOT PROGRAMS
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Program-by-Program Summaries
Building Energy IQ Pilot Program
Description
Formerly known as the Active Energy Management pilot, the Building Energy IQ (BEIQ) pilot program fully launched in
2022 for a three-year term, with 2024 as the last full year. The BEIQ pilot is a strategic energy-management program
that focuses on the commercial sector in both Idaho and Washington. The final study report is planned for Q2 2025.
Program Activities
With 2024 being the last full year of the pilot, no new customers were added. Pilot participants included I
customers having 16 buildings total, seven of which are in Idaho. Teams from Avista and pilot partner Edo identified
potential energy-conservation measures within these buildings and engaged building operators to implement them.
This unfolded through regular monthly meetings, individualized project discussions, and annual performance reports,
along with access to an online tool that customers and the pilot team used to track activities and performance.
Program Changes
Pilot energy savings are being analyzed by Avista's third-party EM&V contractor. After the final evaluation, Avista will
determine if a full program offering is cost-effective and can be delivered more broadly. In the meantime, closeout
activities for pilot participants were completed in Q 1 2025.
Plans for 2025
The pilot will be evaluated in mid-2025 to determine whether a program should be offered.
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�JHfISTA 2024 Idaho Annual Conservation Report Pg 47

Compressed Air Leak Detection Pilot Program
Description
A program to detect leaks in commercial compressed air systems,while offering incentives to repair leaks.
Program Activities
In April 2024 Avista terminated the prior program due to low participation, beginning a pilot mid-year to spark
enrollment and determine how to provide for leak detection and repair while offering a more positive customer
experience. Through a partner vendor, customers were provided with acoustic imaging scans and offered repairs to fix
detected leaks. Once leaks were repaired, a second scan was performed to verify the repair and savings. The pilot data
will be analyzed to inform design of a future program.
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Pg 48 2024 Idaho Annual Conservation Report 04 VISTA

Research and Development
Inland Northwest Center for Energy and Decarbonization
In 2024, Avista led a cross-sector collaboration to establish the Inland Northwest Center for Energy and
Decarbonization (INTENT) by pursuing funds from the U.S. National Science Foundation (NSF) through its Regional
Innovation Engines program. In May 2024, the center was awarded $996,490 through Avista's partner, Urbanova, to
further develop a vision to accelerate innovation and sustained economic growth by building on the region's existing
energy sector.
The scope of the NSF Engines Development Award is to advance energy and decarbonization technologies in the
Inland Northwest.The project will ultimately serve 28 counties in Idaho and Washington (I I in Idaho). Its overarching
goals are to inclusively build the economy, nurture effective investments in innovation, grow and sustain a capable
workforce, and draw use-inspired research and development into building economic opportunities for all residents of
the region. Initially, committed partners include Avista, tribal governments, land grant research universities, national
laboratories, a regional workforce council, nonprofits leading in energy and equity, public and private universities,
public utility districts, angel investment groups, intellectual property experts, state agencies, other economic cluster
organizations, and sector-leading for-profit companies.
Several Idaho entities in Avista's service territory are participating in INTENT, including the University of Idaho, North
Idaho College, the Coeur d'Alene Tribe, and the Nez Perce Tribe.
Avista has not requested research and development(R&D)funds to support research activities related to this project
to date.The INTENT partnership could, however, easily be leveraged in the future to pursue efficiency-specific R&D
projects, particularly if INTENT receives full funding to build out the center.As instructed in Order No.35129 of Case
Nos. AVU-E-20-13 and AVU-G-20-08, Avista will continue exploring R&D prospects that include measurable targets
and metrics that can be met and monitored, and it will file a proposed updated R&D program if such an opportunity is
established.
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�Iu VISTAW 2024 Idaho Annual Conservation Report Pg 49

REGIONAL MARKET TRANSFORMATION
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Avista's local energy-efficiency portfolio consists of programs and supporting infrastructure designed to enhance
and accelerate the saturation of energy-efficiency measures throughout its service territory.This occurs through a
combination of financial incentives,technical assistance, program outreach, and education.
It is not feasible for Avista to independently have a meaningful impact on regional or national markets. Consequently,
utilities within the Pacific Northwest have worked together through the NEEA to address opportunities beyond the
ability or reach of individual utilities. Avista has been participating in and funding NEEA since it was founded in 1997.
Table 54 shows 2024 NEEA savings and the associated costs for Idaho,which exclude internal administrative costs
related to participation in various NEEA activities and studies. NEEA's costs include all expenditures for operations
and value delivery; energy savings initiatives; investments in market training and infrastructure; stock assessments,
evaluations, data collection, and other regional and program research; emerging technology research and
development; and all administrative costs.
TABLE 54 - NEEA ENERGY SAVINGS AND PARTICIPATION COSTS
- NEEA 2024 NEEA Avista 2020-2024
Energy Savings Participation Costs Funding Share
6,952 MWh
Electric (0.79 aMW) $ 679,292 1.69%
Natural Gas 285,431 Therms $ 188,004 3.55%
Avista will continue working closely with NEEA and other regional entities to identify overlapping priorities and
objectives while simultaneously deploying a more thorough and customized local market transformation strategy—
including additional investment in and direct coordination with the supply chain.
Electric Energy Savings Share
Values provided in NEEA's 2024 annual report represent the amounts allocated to Avista's service territory,which is a
combination of site-based energy savings data (where available) or an allocation of savings based on funding share.
NEEA estimates savings at the state level and allocates results to funders based on their share of state residential
accounts from the Energy Information Administration (Form EIA-861).
Natural Gas Energy Savings Share
100 percent of the 285,431 therms acquired through NEEA natural gas savings in Idaho in 2024 were attributed to
changes to the residential code.
/lIW'.iAiiV1STA© 2024 Idaho Annual Conservation Report Pg 51

GLOSSARY OF TERMS
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GLOSSARY OF TERMS
Active energy management(AEM):The implementation of continuous building monitoring to improve building
performance in real time.
adjusted market baseline (AMB):Based on the RTF guidelines; represents a measurement between the energy-
efficient measure and the standard efficiency case that is characterized by current market practice or the
minimum requirements of applicable codes or standards, whichever is more efficient. When applying an AMB, no
net-to-gross factor would be applied since the resultant UES amount would represent the applicable savings to
the grid.
advanced metering infrastructure (AMI): Systems that measure, collect, and analyze energy usage from advanced
devices such as electricity meters, natural gas meters, or water meters through various communication media on
request or on a predetermined schedule.
advisory group:Avista's group of external stakeholders who comment about the company's energy-efficiency
activities.
Air-Conditioning, Heating, and Refrigeration Institute (AHRI):The trade association representing manufacturers
of HVAC and water heating equipment.
~. The amount of energy that would be generated by one megawatt of capacity operating continuously for one
full year. Equals 8,760 MWhs of energy.
American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE): Devoted to the
advancement of indoor environment-control technology in the heating, ventilation, and air-conditioning(HVAC)
industry, ASHRAE's mission is "to advance technology to serve humanity and promote a sustainable world."
Annual Conservation Plan (ACP): An Avista-prepared resource document that outlines the company's conservation
offerings and its approach to energy efficiency, as well as details on verifying and reporting savings.
Annual Conservation Report (ACR): An Avista-prepared resource document that summarizes its annual energy-
efficiency achievements.
annual fuel utilization efficiency(AFUE):A measurement of how efficiently a furnace or boiler uses its fuel.
Applied Energy Group (AEG): A consulting service that provides a wide range of energy-efficiency and demand
response-related management services to assist clients in designing and implementing programs for their
customers.
avoided cost:An investment guideline describing the value of conservation and generation resource investments in
terms of the cost of more expensive resources that would otherwise have to be acquired.
baseline:Conditions, including energy consumption,that would have occurred without implementation of the
subject's energy-efficiency activity. Baseline conditions are sometimes referred to as "business-as-usual"
conditions.
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,,iAiVFSTA& 2024 Idaho Annual Conservation Report Pg 53

baseline efficiency:The energy use of the baseline equipment, process, or practice that is being replaced by a more
efficient approach to providing the same service. It is used to determine the energy savings obtained by the more
efficient approach.
baseline period:The period of time selected as representative of facility operations before an energy-efficiency
activity takes place.
Biennial Conservation Plan (BCP): An Avista-prepared resource document that outlines Avista's conservation
offerings and its approach to energy efficiency, as well as details on verifying and reporting savings for a two-year
period.
Building Owners & Managers Association (BOMA): An international federation of local associations and global
affiliates that represents the owners, managers, service providers, and other property professionals of all
commercial building types.
Business Partner Program (BPP):An outreach effort designed to raise awareness of utility programs and services
that can assist rural small-business customers in managing their energy bills.
British thermal unit(Btu):The amount of heat energy necessary to raise the temperature of I pound of water I
degree Fahrenheit (3,413 Btu are equal to one kilowatt-hour).
busbar:The physical electrical connection between the generator and transmission system.Typically load on the
system is measured at busbar.
Capacity:The maximum power that a machine or system can produce or carry under specified conditions. The
capacity of generating equipment is generally expressed in kilowatts or megawatts. In terms of transmission lines,
capacity refers to the maximum load a line can carry under specified conditions.
coefficient of performance (COP):A ratio of useful heating or cooling provided to work(energy) required for
heat pumps, refrigerators, or air-conditioning systems. Higher COPs equate to more efficient systems and lower
operating costs.
community action programs (CAP): General term for Community Action Programs, Community Action Agencies,
and Community Action Centers that provide services such as low-income weatherization through federal and
state and other funding sources (e.g., utility constitutions).
conservation:According to the Northwest Power Act, any reduction in power consumption because of increases in
the efficiency of energy use, production, or distribution.
Conservation potential assessment (CPA): An analysis of the amount of conservation available in a defined area.
Provides savings amounts associated with energy-efficiency measures to input into the company's IRP process.
cooling degree days:A measure of how hot the temperature was on a given day or during a period of days.A day
with a mean temperature of 80°F has 15 cooling degree days. If the next day has a mean temperature of 83°F,
it has 18 cooling degree days. Historically, the fixed temperature has been set at 65°F,the outdoor temperature
above which cooling was typically needed.
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Pg 54 2024 Idaho Annual Conservation Report ,AiiVJFSTA

cost-effective:According to the Northwest Power Act,a cost-effective measure or resource must be forecast to be
reliable and available within the time it is needed, and to meet or reduce electrical power demand of consumers
at an estimated incremental system cost no greater than that of the least-costly, similarly reliable, and available
alternative or combination of alternatives.
curtailment:An externally imposed reduction of energy consumption due to a shortage of resources.
customer/customer classes:A category(ies) of customer(s) defined by provisions found in tariff(s) published by
the entity providing service,approved by the PUC. Examples of customer classes are residential, commercial,
industrial, agricultural, local distribution company, core, and non-core.
decoupling:In conventional utility regulation, utilities make money based on how much energy they sell.A utility's
rates are set largely based on an estimation of costs of providing service over a set period, with an allowed
profit margin, divided by a forecasted amount of unit sales over the same period. If the actual sales turn out as
forecasted,the utility will recover all fixed costs and its set profit margin. If the actual sales exceed the forecast,
the utility will earn extra profit.
deemed savings: Primarily referenced as UES, an estimate of an energy savings for a single unit of an installed
energy-efficiency measure that (a) has been developed from data sources and analytical methods that are widely
considered acceptable for the measure and purpose, and (b) is applicable to the situation being evaluated.
demand:The load that is drawn from the source of supply over a specified interval of time (in kilowatts, kilovolt-
amperes, or amperes).Also,the rate at which natural gas is delivered to or by a system, part of a system, or piece
of equipment and expressed in cubic feet, therms, Btu, or multiples thereof, for a designated period such as a
24-hour day.
demand response (DR):A voluntary and temporary change in consumers' use of electricity when the power system
is stressed.
demand-side management(DSM):The process of helping customers use energy more efficiently. Used
interchangeably with energy efficiency and conservation, although conservation technically means using less
while DSM and energy efficiency mean using less while still having the same useful output of function.
direct load control(DLC):The means by which a utility can signal a customer's appliance to stop operations to
reduce the demand for electricity. Such rationing generally involves a financial incentive for the affected customer.
discount rate:The rate used in a formula to convert future costs or benefits to their present value.
distribution: The transfer of electricity from the transmission network to the consumer. Distribution systems generally
include the equipment to transfer power from the substation to the customer's meter.
distributed generation (DC):An approach that employs a variety of small-scale technologies to both produce and
store electricity close to the end users of power.
effective useful life (EUL):Sometimes referred to as measure life and often used to describe persistence. EUL is an
estimate of the duration of savings from a measure.
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'.0-lu1111/FSTA© 2024 Idaho Annual Conservation Report Pg 55

emergency operating plan (EOP):A plan that assigns responsibility to organizations and individuals for carrying out
specific actions to respond to an emergency.An EOP sets forth lines of authority, lays out organizational roles and
responsibilities during an emergency, and illustrates how actions will be coordinated. An EOP also describes how
people and property will be protected in emergencies and natural disasters, and identifies personnel, equipment,
facilities, and supplies to use during recovery operations.
end-use:A term referring to the final use of energy; it often refers to the specific energy services (e.g., space
heating), or the type of energy-consuming equipment (e.g., motors).
Energy Assistance Advisory Group (EAAG): An ongoing energy assistance program advisory group to monitor and
explore ways to improve Avista's Low-Income Rate Assistance Program (LIRAP).
Energy Efficiency Advisory Group (EEAG): A group that advises investor-owned utilities on the development of
integrated resource plans and conservation programs.
Equity Advisory Group (EAG): A group that consults on various company endeavors to ensure that all customers are
benefiting from the transition to clean energy through the equitable distribution of energy/non-energy benefits
and reduced energy burdens to vulnerable populations and highly impacted communities.
energy-efficiency measure: Refers to either an individual project conducted or technology implemented to reduce
the consumption of energy at the same or an improved level of service. Often referred to as simply a"measure."
Energy Independence Act (EIA): Requires electric utilities serving at least 25,000 retail customers to use renewable
energy and energy conservation.
energy use intensity(EUI):A metric—energy per square foot per year—that expresses a building's energy use as a
function of its size or other characteristics.
evaluation:The performance of a wide range of assessment studies and activities aimed at determining the effects of
a program (or portfolio) and understanding or documenting performance, cost-effectiveness, levels of demand or
energy savings, related markets and market operations, and program-induced changes in those markets. Market
assessment, monitoring and evaluation, and verification are aspects of evaluation.
Evaluation, Measurement, and Verification (EM&V): Term for evaluation activities at the measure, project,
program or portfolio level; can include impact, process, market, or planning activities. EM&V is distinguishable
from Measurement and Verification (M&V), defined later.
ex-ante savings estimate: Forecasted savings value used for program planning or savings estimates for a measure;
Latin for "beforehand."
ex-post evaluated estimated savings: Savings estimates reported by an independent,third-party evaluator after the
energy impact evaluation has been completed. If only the term "ex-post savings" is used, it will be assumed that
it is referring to the ex-post evaluation estimate,the most common usage; from Latin for"from something done
afterward."
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Pg 56 2024 Idaho Annual Conservation Report ,AiiVJFSTA

external evaluators (a.k.a. third-party evaluators):Independent professional efficiency person or entity retained
to conduct EM&V activities. Consideration will be made for those who are certified M&V professionals (CMVPs)
through the Association of Energy Engineers (AEE) and the Efficiency Evaluation Organization (EVO).
free rider: A common term in the energy-efficiency industry meaning a program participant who would have
installed the efficient product or changed a behavior regardless of any program incentive or education received.
Free riders can be total, partial, or deferred.
generation:The act or process of producing electricity from other forms of energy.
Green Motors Practices Croup (CMPC):A nonprofit corporation governed by electric motor service center
executives and advisers whose goal is the continual improvement of the electric motor repair industry.
gross savings:The change in energy consumption or demand that results from energy-efficiency programs,codes,
standards, and naturally occurring adoption, with a long-lasting savings effect regardless of why they were
enacted.
heating degree days:A measure of the amount of heat needed in a building over a fixed period, usually a year.
Heating degree days per day are calculated by subtracting from a fixed temperature the average temperature over
the day. Historically, the fixed temperature has been set at 65°F, the outdoor temperature below which heat was
typically needed. As an example, a day with an average temperature of 45°F would have 20 heating degree days,
assuming a base of 65°F.
Heating Seasonal Performance Factor(HSPF): Defined as the ratio of heat output over the heating season to the
amount of electricity used in air-source or DHP equipment.
Heating, Ventilation, and Air-Conditioning(HVAC):Sometimes referred to as climate control, HVAC is particularly
important in the design of medium to large industrial and office buildings where humidity and temperature must
all be closely regulated while maintaining safe and healthy conditions within.
high-intensity discharge (HID)fixture:A fixture that is bright and powerful enough to throw a high amount of
lumens an extremely long distance; often used in very large spaces such as manufacturing facilities or sports
stadiums.
HOU.Hours of use (an annual estimation of lighting or HVAC equipment operation hours).
Idaho Public Utilities Commission (IPUC): Regulators of investor-owned or privately owned utilities that provide
natural gas, water, electricity, or some telephone services for profit.
impact evaluation:Determination of directly or indirectly induced program-specific changes (e.g.,energy or demand
usage) attributable to an energy-efficiency program.
implementer:Avista employee whose responsibilities are directly related to operations and administration of energy-
efficiency programs and activities, and who may have energy savings targets as part of their employee goals or
incentives.
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�drV15TA' 2024 Idaho Annual Conservation Report Pg 57

incremental cost:The difference between the cost of baseline equipment or services and the cost of alternative
energy-efficient equipment or services.
installation verification (IV) report: A detailed report documenting installed conservation measures on a site-
specific project.
Integrated Resource Plan (IRP):An IRP is a comprehensive evaluation of future electric or natural gas resource
plans. The IRP must evaluate the full range of resource alternatives to provide adequate and reliable service to a
customer's needs at the lowest possible risk-adjusted system cost. These plans are filed with the state public utility
commission on a periodic basis.
Integrated Resource Plan Technical Advisory Committee (IRP TAC):Advisory committee for the IRP process that
includes internal and external participants.
International Performance Measurement and Verification Protocol (IPMVP): A guidance document with a
framework and definitions describing the four M&V approaches; a product of the Energy Valuation Organization
(evo-world.org).
investor-owned utility(IOU):A utility that is organized under state law as a corporation to provide electric power
service and earn a profit for its stockholders.
kilowatt(kW):The electrical unit of power that equals 1,000 watts.
kilowatt-hour(kWh):A basic unit of electrical energy that equals one kilowatt of power applied for one hour.
kilo British thermal unit(kBtu): Btu,which stands for British thermal units, measures heat energy. Each Btu equals
the amount of heat needed to raise I pound of water I degree Fahrenheit; the prefix kilo means 1,000, which
means that a kBtu equals 1,000 Btu.
Levelized Cost of Energy(LCOE):The present value of a resource's cost(including capital,financing, and operating
costs) converted into a stream of equal annual payments. This stream of payments can be converted to a unit
cost of energy by dividing them by the number of kilowatt-hours produced or saved by the resource in associated
years. By leveling costs, resources with different lifetimes and generating capabilities can be compared.
line losses:The amount of electricity lost or assumed lost when transmitting over transmission or distribution lines.
This is the difference between the quantity of electricity generated and the quantity delivered at some point in the
electric system.
Low-Income Home Energy Assistance Program (LIHEAP): Federal energy assistance program available to
qualifying households based on income, usually distributed by CAAs or partnerships.
Low-Income Rate Assistance Program(LIRAP):LIRAP provides funding(collected from Avista's tariff rider)to CAAs
for distribution to Avista customers who are least able to afford their utility bill.
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market effect evaluation:An evaluation of the change in the structure or functioning of a market,or the behavior
of participants in a market, that results from one or more program efforts. Typically, the resultant market or
behavior change leads to an increase in the adoption of energy-efficient products, services, or practices.
measure (also energy-efficiency measure, or EEM): Installation or modification of equipment—whether a single
piece, subsystem, or system —or operation at an end-use energy consumer facility for the purpose of reducing
energy use and/or demand (and associated costs) at a comparable level of service.
measure life: See Effective Useful Life (EUL).
Measurement and Verification (M&V):A subset of program impact evaluation associated with the documentation
of energy savings at individual sites or projects, using one or more methods that can involve measurements,
engineering calculations, statistical analyses, or computer modeling. M&V approaches are defined in the
International Performance Measurement and Verification Protocol (available at evo-world.org).
megawatt(MW):The electrical unit of power that equals I million watts or 1,000 kilowatts.
megawatt-hour(MWh):A basic unit of electrical energy that equals one megawatt of power applied for one hour.
net savings:The change in energy consumption or demand attributable to an energy-efficiency program. This change
in energy use or demand may include, implicitly or explicitly, consideration of factors such as free drivers, non-net
participants (free riders), participant and non-participant spillover, and induced market effects. These factors may
be considered in how a baseline is defined or in adjustments to gross savings values.
non-energy benefit/non-energy impact (NEB/NEI): The quantifiable non-energy impacts (NEIs) associated with
program implementation or participation; also referred to as non-energy benefits(NEBs)or co-benefits. Examples
of NEIs include water savings, non-energy consumables, and other quantifiable effects. The value is most often
positive, but may also be negative (e.g., the cost of additional maintenance associated with a sophisticated,
energy-efficient control system).
Northwest Energy Efficiency Alliance (NEEA): A nonprofit organization that works to accelerate energy efficiency
in the Pacific Northwest through the adoption of energy-efficient products, services, and practices.
Northwest Power and Conservation Council(NWPCC):An organization that develops and maintains both a
regional power plan and a fish and wildlife program to balance the environmental and energy needs of the Pacific
Northwest.
outside air temperature (OAT): Refers to the temperature of the air around an object, but unaffected by the object.
on-bill repayment/financing (OBR): A financing option in which a utility or private lender supplies capital to a
customer to fund energy efficiency, renewable energy, or other generation projects. It's repaid through regular
payments on an existing utility bill.
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,,r-IIFW.5TA 2024 Idaho Annual Conservation Report Pg 59

Participant Cost Test (PCT):The PCT measures quantifiable costs and benefits to the customer participating in a
program — including, for example, the incentive paid by the utility under the program, as well as non-energy
impacts. Since many customers do not base their decision to participate in a program entirely on quantifiable
variables, this test cannot be a complete measure of the benefits and costs of a program to a customer.
portfolio:Collection of all programs conducted by an organization. In the case of Avista, its portfolio includes electric
and natural gas programs in all customer segments. Portfolio can also be used to refer to a collection of similar
programs addressing the market. In this sense of the definition, Avista has an electric portfolio and a natural gas
portfolio with programs addressing the various customer segments.
prescriptive:A prescriptive program is a standard offer of incentives for the installation of an energy-efficiency
measure. Prescriptive programs are generally applied when the measures are employed in relatively similar
applications.
process evaluation:A systematic assessment of an energy-efficiency program or program component for the
purposes of documenting operations at the time of the examination, and identifying and recommending
improvements to increase the program's efficiency or effectiveness for acquiring energy resources while
maintaining high levels of participant satisfaction.
program:An activity, strategy, or course of action undertaken by an implementer. Each program is defined by a
unique combination of program strategy, market segment, marketing approach, and energy-efficiency measure(s)
included. Examples are a program to install energy-efficient lighting in commercial buildings and residential
weatherization programs.
project:An activity or course of action involving one or multiple energy-efficiency measures at a single facility or site.
ratepayer impact (RIM):A cost-effectiveness test that measures how customer bills or rates are affected by the
changes in utility revenues and operating costs caused by the program. This test indicates the direction and
magnitude of the expected change in customer bills or rate levels. Lower values equate to less impact on
customer bills.
Regional Technical Forum of the Northwest Power and Conservation Council(RTF):A technical advisory
committee to the NWPCC established in 1999 to develop standards to verify and evaluate energy-efficiency
savings.
realization rate (RR):Ratio of ex ante reported savings to ex-post evaluated estimated savings.When realization
rates are reported,they are labeled to indicate whether they refer to comparisons of(a) ex ante gross reported
savings to ex-post gross evaluated savings, or (b) ex ante net reported savings to ex-post net evaluated savings.
reliability:When used in energy-efficiency evaluation, the quality of a measurement process that would produce
similar results on (a) repeated observations of the same condition or event, or (b) multiple observations of the
same condition or event by different observers. Reliability refers to the likelihood that the observations can be
replicated.
reported savings:Savings estimates reported by Avista for an annual (calendar) period.These savings will be based
on best available information.
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request for proposal(RFP):Business document that announces and provides details about a project,as well as
solicits bids from potential contractors.
retrofit:To modify an existing generating plant,structure,or process.The modifications are done to improve energy
efficiency, reduce environmental impacts, or to otherwise improve the facility.
rigor:The level of expected confidence and precision.The higher the level of rigor,the more confident one is that the
results of the evaluation are both accurate and precise, i.e., reliable.
R-value or R-factor(resistance transfer factor):Measures how well a barrier,such as insulation, resists the
conductive flow of heat.
Schedules 90 and 190: Rate schedules that show energy-efficiency programs.
Schedules 91 and 191: Rate schedules that are used to fund energy-efficiency programs.
sector(s):The economy is divided into four sectors for energy planning: residential, commercial (e.g., retail stores,
office, and institutional buildings), industrial, and agriculture (e.g., dairy farms, irrigation).
service territory: The areas in Idaho,Washington, and Oregon served by Avista to provide either natural gas or
electric service (or both).
site-specific:A commercial/industrial program offering individualized calculations for incentives upon any electric or
natural gas efficiency measure not incorporated into a prescriptive program.
simple payback:The time required before savings from a particular investment offset costs,calculated by investment
cost divided by value of savings (in dollars). For example, an investment costing $100 and resulting in a savings of
$25 each year would be said to have a simple payback of four years. Simple paybacks do not account for future
cost escalation or other investment opportunities.
spillover: Reductions in energy consumption or demand caused by the presence of an energy-efficiency program,
beyond the program-related gross savings of the participants and without direct financial or technical assistance
from the program.There can be participant or non-participant spillover(sometimes referred to as"free drivers").
Participant spillover is the additional energy savings that occur because of the program's influence when a
program participant independently installs incremental energy-efficiency measures or applies energy-saving
practices after having participated in the energy-efficiency program. Non-participant spillover refers to energy
savings that occur when a program non-participant installs energy-efficiency measures or applies energy savings
practices because of a program's influence.
Technical Reference Manual (TRM):An Avista-prepared resource document that contains Avista's (ex ante) savings
estimates, assumptions and sources for those assumptions, guidelines, and relevant supporting documentation
for its natural gas and electric energy-efficiency prescriptive measures. This document is populated and vetted by
the RTF and third-party evaluators.
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�11iV1STA 2024 Idaho Annual Conservation Report Pg 61

total resource Cost(TRC):A cost-effectiveness test that assesses the impacts of a portfolio of energy-efficiency
initiatives regardless of who pays the costs or who receives the benefits. The test compares the present value
of costs of efficiency for all members of society (including all costs to participants and program administrators)
compared to the present value of all quantifiable benefits, including avoided energy supply and demand costs and
non-energy impacts.
transmission:The act or process of long-distance transport of electric energy,generally accomplished by elevating the
electric current to high voltages. In the Pacific Northwest, Bonneville operates most of the high-voltage, long-
distance transmission lines.
uniform energy factor(UEF): A measurement on how efficiently a water heater utilizes its fuel.
unit estimated savings: Defines the first-year kWh savings value for an energy-efficiency measure.
U-value or U-factor:The measure of a material's ability to conduct heat, numerically equal to I divided by the value
of the material. Used to measure the rate of heat transfer in windows. The lower the U-factor, the better the
window insulates.
Uncertainty:The range or interval of doubt surrounding a measured or calculated value within which the true value
is expected to fall within some degree of confidence.
utility Cost test(UCT):One of the four standard practice tests commonly used to evaluate the cost-effectiveness of
DSM programs.The UCT evaluates the cost-effectiveness based upon a program's ability to minimize overall utility
costs. The primary benefits are the avoided cost of energy in comparison to the incentive and non-incentive utility
costs.
variable frequency drive (VFD):A type of motor drive used in electromechanical drive systems to control AC motor
speed and torque by varying motor input frequency and voltage.
verification:An assessment that the program or project has been implemented per its design. For example, the
objectives of measure installation verification are to confirm (a)the installation rate, (b) that the installation meets
reasonable quality standards, and (c) that the measures are operating correctly and have the potential to generate
the predicted savings. Verification activities are generally conducted during on-site surveys of a sample of projects.
Project site inspections, participant phone and mail surveys, or implementer and consumer documentation review
are typical activities associated with verification. Verification may include one-time or multiple activities over the
estimated life of the measures and review of commissioning or retro-commissioning documentation. It can also
include review and confirmation of evaluation methods used, samples drawn, and calculations used to estimate
program savings. Project verification may be performed by the implementation team, but program verification is a
function of the third-party evaluator.
vulnerable population: Communities that experience a disproportionate cumulative risk from environmental
burdens.
weather normalized:This is an adjustment that is made to actual energy usage, stream-flows, etc.,which would
have happened if"normal"weather conditions would have taken place.
,Anw-
Pg 62 2024 Idaho Annual Conservation Report �4MISTA

weighted average Cost of Capital(WACQ:A calculation of a firm's cost of capital in which each category of capital
is proportionately weighted. All sources of capital, including common stock, preferred stock, bonds, and any
other long-term debt, are included in a WACC calculation.
8,760:Total number of hours in a year.
�IIIV�STa 2024 Idaho Annual Conservation Report Pg 63

APPENDICES AND SUPPLEMENTS
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APPENDIX A - 2024 ELECTRIC IMPACT EVALUATION REPORT
dft &IM
Evaluation, Measurement and
Verification ( EM &V) of Avista Idaho
Electric PY2024 Residential,
Low-Income, and Nonresidential
Energy Efficiency Programs
SUBMITTED TO: AVISTA UTILITIES
SUBMITTED ON : AUGUST 19, 2025
SUBMITTED BY: ADM ASSOCIATES, INC.
ADM Associates, Inc Avista Utilities
3239 Ramos Circle 1411 E. Mission Ave.
Sacramento,CA 95827 Spokane,WA 99252
2024 Idaho Annual Conservation Report Appendices

Avista Idaho PY2024
Table of Contents
1. Executive Summary.............................................................................................................................6
1.1 Savings Results............................................................................................................................................6
1.2 Conclusions and Recommendations...........................................................................................................7
2. General Methodology......................................................................................................................... 14
2.1 Glossary of Terminology...........................................................................................................................14
2.2 Summary of Approach..............................................................................................................................15
3. Residential Impact Evaluation Results...............................................................................................28
3.1 Simple Verification Results.......................................................................................................................28
3.2 Program-Level Impact Evaluation Results................................................................................................30
4. Low-Income Impact Evaluation Results............................................................................................51
4.1 Program-Level Impact Evaluation Results................................................................................................51
5. Non-Residential Impact Evaluation Results.......................................................................................54
5.1 Database& Document Verification..........................................................................................................54
5.2 Survey and On-Site Verification................................................................................................................55
5.3 Program-Level Impact Evaluation Results................................................................................................56
6. Appendix A: Billing Analysis Results...............................................................................................87
6.1 Home Energy Audit Program....................................................................................................................87
7. Appendix B: Summary of Survey Respondents.................................................................................90
8. Appendix C: Site-Specific M&V Reports..........................................................................................92
Tables of Contents and Tables ii

Avista Idaho PY2024
List of Tables
Table 1-1: Residential Verified Impact Savings by Program .........................................................................6
Table 1-2: Low-Income Expected Savings by Program .................................................................................6
Table 1-3: Nonresidential Verified Impact Savings by Program ...................................................................6
Table 1-4: Impact Evaluation Activities by Program and Sector...................................................................7
Table 2-1: Document-based Verification Samples and Precision by Program ...........................................19
Table 2-2: Survey-Based Verification Sample and Precision by Program...................................................20
Table 3-1: Residential Verified Impact Savings by Program .......................................................................28
Table 3-2: Summary of Survey Response Rate...........................................................................................29
Table 3-3: State-Specific Simple Verification Precision by Program...........................................................29
Table 3-4: Mixed State-Specific Simple Verification Precision by Program................................................29
Table 3-5: Fuel Efficiency Program ISRs by Measure..................................................................................30
Table 3-6:Appliance Program ISRs by Measure.........................................................................................30
Table 3-7: Shell Program Measures............................................................................................................31
Table 3-8: Shell Program Verified Electric Savings......................................................................................32
Table 3-9: Shell Program Incentive Costs by Measure................................................................................33
Table 3-10: Fuel Efficiency Program Measures...........................................................................................35
Table 3-11: Fuel Efficiency Program Verified Electric Savings....................................................................35
Table 3-12: Fuel Efficiency Program Incentive Costs by Measure..............................................................35
Table 3-13: Fuel Efficiency Verification Survey ISR Results ........................................................................36
Table 3-14: ENERGY STAR' Homes Program Measures .............................................................................38
Table 3-15: ENERGY STAR® Homes Program Verified Electric Savings.......................................................38
Table 3-16: ENERGY STAR' Homes Program Incentive Costs by Measure.................................................38
Table 3-17:Appliances Program Measures ................................................................................................40
Table 3-18:Appliances Program Verified Electric Savings..........................................................................41
Table 3-19:Appliances Program Incentive Costs by Measure....................................................................42
Table 3-20:Appliances Program Verification Survey ISR Results...............................................................43
Table 3-21: Midstream Program Measures................................................................................................45
Table 3-22: Midstream Program Verified Electric Savings..........................................................................46
Table 3-23: Midstream Program Costs by Measure...................................................................................46
admenergy.com 13239 Ramos Circle, Sacramento, CA 95827 1 916.363.8383 iii

Avista Idaho PY2024
Table 3-24: On Bill Repayment Program Claimed Electric Savings.............................................................48
Table 3-25: On Bill Repayment Program Claimed Costs by Measure.........................................................48
Table 3-26: Home Energy Audit Program Verified Electric Savings............................................................49
Table 3-27: Home Energy Audit Program Costs by Measure......................................................................49
Table 3-28: Double Counted Savings Removed, Home Energy Audit Program..........................................50
Table 4-1: Low-Income Verified Impact Savings by Program .....................................................................51
Table 4-2: Low-Income Program Measures................................................................................................52
Table 4-3: Low-Income Program Verified Electric Savings .........................................................................53
Table 4-4: Low-Income Program Incentive Costs by Measure ...................................................................53
Table 5-1: Non-Residential Verified Impact Savings by Program ...............................................................54
Table 5-2: Prescriptive Program Verification Precision ..............................................................................55
Table 5-3: Survey Verification.....................................................................................................................55
Table 5-4: On-Site Verification....................................................................................................................56
Table 5-5: Prescriptive Lighting Program Measures...................................................................................57
Table 5-6: Interior Prescriptive Lighting Program Verified Electric Savings ...............................................58
Table 5-7: Prescriptive Lighting Program Incentives...................................................................................59
Table 5-8: Prescriptive Lighting Program Verification Precision.................................................................60
Table 5-9: Prescriptive Lighting Program Verification Findings..................................................................61
Table 5-10: Lighting In-Service Rates..........................................................................................................61
Table 5-11: Small Business Lighting Program Measures.............................................................................62
Table 5-12: Small Business Lighting Program Verified Electric Savings......................................................63
Table 5-13: Small Business Lighting Program Costs by Measure................................................................65
Table 5-14: Small Business Lighting Program Verification Precision..........................................................67
Table 5-15: Prescriptive Lighting Program Verification Findings................................................................67
Table 5-16: Prescriptive HVAC VFD Program Measures.............................................................................69
Table 5-17: Prescriptive HVAC VFD Program Verified Electric Savings.......................................................69
Table 5-18: Prescriptive HVAC VFD Program Incentives.............................................................................69
Table 5-19: Prescriptive HVAC VFD Program Verification Precision...........................................................70
Table 5-20: Grocer Program Measures.......................................................................................................71
Table 5-21: Grocer Program Verified Electric Savings................................................................................72
Table 5-22: Grocer Program Incentives......................................................................................................72
admenergy.com 13239 Ramos Circle, Sacramento, CA 95827 1 916.363.8383 iv

Avista Idaho PY2024
Table 5-23:Verification Precision...............................................................................................................73
Table 5-24: Prescriptive Shell Program Measures......................................................................................74
Table 5-25: Prescriptive Shell Program Verified Electric Savings................................................................74
Table 5-26: Shell Program Incentives..........................................................................................................74
Table 5-27: Prescriptive Shell Program Verification Precision....................................................................75
Table 5-29: Green Motors Program Measures...........................................................................................76
Table 5-30: Green Motors Program Electric Savings..................................................................................76
Table 5-31: Non-Residential Midstream Program Measures .....................................................................77
Table 5-32: Non-Residential Midstream Program Verified Electric Savings...............................................78
Table 5-33: Non-Residential Midstream Incentives....................................................................................78
Table 5-34: Non-Residential Midstream Program Verification Precision...................................................78
Table 5-35: Site-Specific Program Verified Electric Savings........................................................................80
Table 5-36: Site-Specific Program Lighting and Non-Lighting Savings........................................................80
Table 5-37: Site-Specific Program Incentives..............................................................................................80
Table 5-38: Site-Specific Program Sample Design ......................................................................................81
Table 5-39: Site-Specific Program Sample Summary..................................................................................81
Table 5-40: Site-Specific Expected,Adjusted and Verified kWh Savings by Sampled Project....................82
Table 5-41: Site-Specific Summary of kWh Savings by Sample Stratum and Overall.................................83
Table 5-42: Site-Specific Summary of kWh Savings by End Use.................................................................83
Table 5-43: Building Operator Certification Program UES Sources.............................................................85
Table 5-44: BOC Program Verified Electric Savings ....................................................................................85
Table5-45: BOC Incentives.........................................................................................................................85
Table 6-1: Measures Considered for Billing Analysis, Home Energy Audit Program..................................87
Table 6-2: Cohort Restrictions, Home Energy Audit Program ....................................................................87
Table 6-3: Pre-period Usage T-test for Home Energy Audit Program Washington and Idaho...................88
Table 6-4:Weighted Participants, Home Energy Audit Program ...............................................................89
Table 6-5: Regression Savings, Home Energy Audit Program.....................................................................89
Table 6-6: Double Counted Savings Removed, Home Energy Audit Program............................................89
Table 7-1:Type and Number of Measures Received by Respondents.......................................................90
Table 7-2: Survey Respondent Home Characteristics.................................................................................91
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Avista Idaho PY2024
1. Executive Summary
This report is a summary of the Residential, Low-Income, and Nonresidential Electric Evaluation,
Measurement, and Verification (EM&V) effort of the 2024 program year(PY2024) portfolio of
programs for Avista Corporation (Avista) in the Idaho service territory.The evaluation was
administered by ADM Associates, Inc. (herein referred to as the "Evaluators").
1.1 Savings Results
The Evaluators conducted an impact evaluation for Avista's Residential, Low-Income, and Nonresidential
programs for PY2024. The Residential portfolio savings amounted to 2,390,777 kWh with a 118.22%
realization rate.The Low-Income portfolio savings amounted to 68,878 kWh; however, this portfolio
was not evaluated in PY2024 and therefore does not have a realization rate associated with the
portfolio.The Nonresidential savings amounted to 27,694,878 with a 96.2% realization rate. The
Evaluators summarize the Residential, Low-Income, and Nonresidential portfolio verified savings in
Table 1-1 through Table 1-3, respectively.
Table 1-1: Residential Verified Impact Savings by Program
ir I -Expected Savings Verified Savings Verified Realization
Program (kWh) IF (kWh) Rate
Shell 189,092 214,110 113.23
Fuel Efficiency 105,612 103,207 97.72%
ENERGY STAR Homes 85,018 77,951 91.69%
Appliances 150,143 94,924 63.22%
Midstream 1,492,479 1,891,167 126.71
On Bill Repayment NA NA NA
Home Energy Audit NA 9,418 NA
Total 2,022,344 2,390,777 118.22%
Table 1-2:Low-Income Expected Savings by Program
Program Expected Savings Verified Savings Verified Realization
Low-Income 777764,878 NA NA
Total 1 64,878 NA NA
Table 1-3:Nonresidential Verified Impact Savings by Program
Program Expected Savings Verified Savings Verified Realization
Prescriptive Lighting 6,963,399 6,888,639 98.93%
Small Business Lighting 16,181,397 15,161,166 93.70%
H VAC 81,760 115,111 140.79
Grocer 37,199 37,199 100.00%
Shell 16,263 16,263 100.0%
Green Motors No PY2024 participation
Midstream 179,583 172,150 95.86
Site-Specific 5,335,550 5,185,350 97.18%
Building Operator Certification N/A 119,000 N/A
Total 28,795,151 27,694,878 96.18%
Table 1-4 summarizes the electric programs offered to Residential, Low-income, and Nonresidential
Measurement and Evaluation Report 6

Avista Idaho PY2024
customers in the Idaho Avista service territory in PY2024 as well as the Evaluators' evaluation tasks and
impact methodology for each program.
Table 1-4:Impact Evaluation Activities by Program and Sector
_F Sector rogram'I D.
Review Verification7 impact ... .
Residential Shell ✓ RTF LIES
Residential Fuel Efficiency ✓ ✓ RTF LIES
Residential ENERGY STAR® Homes ✓ RTF LIES
Residential Appliances ✓ ✓ RTF LIES, Billing Analysis
Engineering Algorithm
Residential Midstream ✓ with RTF Baseline
Assumptions
Residential On Bill Repayment ✓ Not Evaluated in 2024
Residential Home Energy Audit ✓ Billing Analysis
Low-Income Low-Income ✓ Not Evaluated in 2024
Nonresidential Lighting ✓ ✓ Prescriptive Engineering
Algorithms
Nonresidential HVAC ✓ Avista TRM
Nonresidential Food Service Equipment ✓ RTF LIES,Avista TRM
Nonresidential Grocer ✓ RTF LIES
Nonresidential Shell ✓ Avista TRM
Nonresidential Green Motors ✓ RTF LIES
Nonresidential Midstream ✓ RTF LIES,Avista TRM
Nonresidential Site-Specific ✓ IPMVP
*No verification surveys were completed in PY2024.The Evaluators reference verification survey results from PY2023.
1.2 Conclusions and Recommendations
The following section details the Evaluators' conclusions and recommendations for each the Residential
Portfolio, Low-Income Portfolio, and Nonresidential Portfolio program evaluations.
1.2.1 Conclusions
The following section details the Evaluator's findings resulting from the program evaluations for each
the Residential Portfolio, Low-Income Portfolio, and Nonresidential Portfolio.
1.2.1.1 Residential Programs
The Evaluators provide the following conclusions regarding Avista's Residential electric programs:
The Evaluators found the Residential portfolio to demonstrate a total of 2,390,777.39 kWh with
a realization rate of 118.22%.
The Residential Portfolio impact evaluation resulted in a realization rate of 118.22% due to
verified savings of 126.71% in the Midstream Program. The Evaluators utilized engineering
algorithms to evaluate this program based on purchased equipment efficiency level. The
Evaluators also applied RTF market practice baseline equivalents to the engineering algorithms
in order to maintain consistency with evaluation methods between the downstream and
midstream programs, while taking into account the often higher efficiency values of the
purchased equipment. In some cases, the implementer applied more efficient than necessary
Measurement and Evaluation Report 7

Avista Idaho PY2024
baselines for projects completed in PY2024.This led to an upward adjustment for a portion of
the Midstream measures.
■ The Evaluators conducted verification surveys for a random sample of customers who had
participated in the residential prescriptive rebates programs in PY2023. Since there was not a
process evaluation completed in PY2024 due to a change in evaluation cadence,the Evaluators
applied the in-service rates determined from the PY2023 survey efforts to the PY2024 projects.
The Evaluators calculated in-service rates for measures in which in-service rates are not typically
100% (clothes washers and dryers, smart thermostats, etc.).The Evaluators found that all
surveyed measures responses indicated in-service rates of between 90 to 100%.These values
were applied to impact analysis results to estimate verified savings through the programs.
■ The Midstream Program, which comprises 73%of the overall expected residential electric
savings, had a realization rate of 126.71%whereas all of the other residential programs
combined yielded a 93% realization rate.The higher-than-expected savings in the Midstream
Program is the main reason we see a residential program-wide realization rate of 118.22%.
■ The Shell Program displayed a realization rate of 113.23%with verified savings of 214,110 kWh.
Differences in the granularity of the Avista TRM and the RTF workbook calculations are the
primary cause of this non-100% realization rate.
o A lack of granularity in the Avista TRM data led to substantial deviation from 100%
realization rates for attic insulation and window measures. More specifically,the RTF
unit energy savings (UES) measure workbook assigns savings values by climate zone and
heating type, while the Avista TRM applies a single savings value for all customers.The
expected savings calculations also appeared to use a value of 1.86 kWh per square foot
for attic savings calculations while the RTF UES aligns closer with the value of 0.6 kWh
per square footage based on home characteristics. Similarly,there were differences in
RTF values and the Avista TRM value for window replacement savings. For single-family
single-pane window replacement customers this difference yielded a realization rate of
64.09%.The Evaluators recommend that Avista ensure that the correct RTF UES values
are used to calculate expected savings and that Avista incorporate more granularity by
climate zone, heating type, and U-value savings into Avista's TRM.
o In addition to the discrepancy in applied unit energy savings values, the Evaluators
identified many discrepancies in the documentation provided in terms of square footage
and unit quantity verification which caused savings to deviate from 100%. In particular,
ex-ante single-pane multifamily window savings calculations seemed to be based on
window quantity as opposed to total window square footage (as is the case in the RTF
UES workbook). This difference in calculation structure yielded a realization rate of
339.6%for the multifamily window replacement from single pane measure. Ultimately,
these differences in Avista TRM vs. RTF assumptions led to an overall realization rate of
113.23%for the Shell Program.
Measurement and Evaluation Report 8

Avista Idaho PY2024
■ The ENERGY STAR Homes Program had a realization rate of 91.69%with verified savings of
77,951 kWh.The Evaluators found that realization rates differed from 100%due to the fact that
the RTF differentiates savings by heating zone and cooling zone, while the Avista TRM does not.
In addition,the Evaluators found that realization rates differed from 100%due to limited
customer application form information. Program application forms frequently lacked
information about home primary and secondary space and water heating type as well as heating
and cooling zones.The Evaluators recommend updating the Avista measure savings database to
match the primary heating type for dual fuel households as well as heating and cooling zones
reflected in the RTF workbooks. In addition,the Evaluators recommend updating document data
aggregation to ensure consistency between the tracking database and the provided rebate
forms.
■ The Fuel Efficiency Program was had a realization rate of 97.72%with verified savings of
103,207 kWh.The Evaluators found that the realization rate deviated from 100%due to two
projects in which the 80%AHRI AFUE values did not meet the minimum criteria to qualify for
calculated savings.The applied Avista TRM prescriptive savings values and the verified savings
aligned in the tracking data, however, the exclusion of savings from these two projects caused
the program's realization rate to drop down to 97.72%.The Evaluators noted that the required
information was validated by Avista employees prior to confirming the rebate and that the ex-
ante claimed kWh and Therms savings values aligned with those outlined in the Avista TRM.The
Evaluators recommend updating the Avista tracking database to capture previous heating types
for conversion measures. In addition,the Evaluators would recommend requiring home
previous heating type, existing cooling type, and home type as inputs on the rebate application
forms. Lastly,the Evaluators would suggest Avista enforce required document submission for all
rebates, such as the AHRI documentation and/or full model number in order to verify measure
efficiency.
■ The Appliances Program displayed a 63.22% realization rate with verified savings of 94,924
kWh.The Evaluators note that Avista TRM defines appropriate unit energy savings for the
fridge-freezer and upright freezer measures.The Evaluators found the program verified savings
resulted in a 63.22% realization rate due to a variety of reasons.The Evaluators found that
although most refrigerator/freezer models met ENERGY STAR requirements,the expected
savings values applied to each refrigerator/freezer was the ESME-rated UES defined by the RTF,
which is significantly higher than ENERGY STAR-qualified products.This led to a low realization
rate for these measure categories.Additionally, the Avista TRM currently assigns smart
thermostats rebated through the program the highest available option defined by the RTF
workbook. However,this efficiency option does not align with project-level documents.The
Evaluators also found that eight smart thermostat projects did not qualify based on RTF LIES
requirements due to lack of occupancy sensors.The Evaluators recommend Avista update the
smart thermostat and refrigerator/freezer expected savings to align with observed efficiency
products rebated through the program rather than the highest efficiency option or highest
savings value option defined by the RTF.
Measurement and Evaluation Report 9

Avista Idaho PY2024
■ The Midstream Program displayed a 126.71% realization rate in PY2024 with 1,891,167 kWh in
verified savings.This is a large improvement compared to the PY2023 impact evaluation result
for this program.The Evaluators reviewed the implementer expected savings values along with
verified tracking data to estimate net adjusted program savings for those measures. In order to
calculate verified savings,the Evaluators utilized industry-standard engineering algorithms using
purchased equipment efficiency values and RTF-defined market practice baseline values,where
appropriate.The Evaluators concluded that the implementers correctly estimated expected
savings values for a portion of the projects, and incorrectly defined above market practice
efficiency baseline for a portion of projects, leading to a realization rate larger than 100%.The
Evaluators recommend incorporating appropriate baselines for each project, reflecting the RTF
market practice baseline present in the year in which the project was installed.
■ The Home Energy Audit Program displayed verified savings of 9,418 kWh. In PY2024,the
Evaluators successfully identified Home Energy Audit Program participant impacts through a
billing analysis.The billing analysis incorporated the census of participants in Washington and
Idaho.The Evaluators then extrapolated household-level savings to the weighted number of full-
year participants in PY2024, after removing double counted savings from other Avista program
participation.These impacts summarize the educational and behavioral impacts offered through
the program audits and expert contractor communications.The Evaluators estimated a total of
165 kWh impacts for each home that received a home energy audit through the program.
1.2.1.2 Low-Income Programs
The Evaluators provide the following conclusions regarding Avista's Low-Income electric programs:
■ The Evaluators found the Low-Income Program displayed an expected savings value of
64,877.67 kWh.The Evaluators do not define a realization rate for this portfolio, as the Low-
Income Program was not evaluated in PY2024.
■ The Evaluators did not complete an impact evaluation for the Low-Income Program. Instead,
impact evaluation is planned for the PY2025 evaluation cycle.
1.2.1.3 Nonresidential Programs
The Evaluators provide the following conclusions regarding Avista's Nonresidential electric programs:
■ The verified savings for the Non-Residential portfolio are 27,694,878 kWh with a realization rate
of 96.2%.
■ The verified savings for the Prescriptive Lighting Program are 6,888,639 kWh with a realization
rate of 98.9%.The Evaluators used the RTF Midstream Lighting workbooks and assigned ISRs
according to the rates shown above in Table 5-10, resulting in slightly lower verified savings than
expected.
■ The verified savings for the Small Business Lighting Program are 15,161,166 kWh with a
realization rate of 93.70%. For measures without occupancy sensors, realization is±1%of
expectations, with any differences likely due to rounding. For measures with occupancy
sensors,the Evaluators found that expected savings were calculated by applying the occupancy
Measurement and Evaluation Report 10

Avista Idaho PY2024
sensor reduction factor to both the operating hours and the connected load of the lighting
retrofit, slightly 'double counting' savings.To account for occupancy sensor savings in verified
calculations,the Evaluators applied the 32% reduction to the operation of the post-install
equipment,then added this value to the retrofit savings, resulting in slightly lower verified
savings.
■ The verified savings for the Prescriptive HVAC Program are 115,111 kWh with a realization rate
of 140.8%. Appropriate RTF UES were assigned to each measure based on horsepower
controlled and type of HVAC equipment.
■ The verified savings for the Grocer Program are 37,199 kWh with a realization rate of 100.00%.
■ The verified savings for the Shell Program are 16,263 kWh with a realization rate of 100.0%.
■ The Green Motors Rewind Program had no PY2024 participation.
■ The Midstream Program verified savings are 172,150 kWh with a realization rate of 95.9%.
o Fryers:The source of expected savings is unclear.Verified savings were sourced from
the RTF and reflect electric savings for a 'standard vat-sized fryer.
o Mini/Multi Splits:The Evaluators were unable to fully recreate expected savings,
though for 45 new construction projects, a 7.1 was used as a baseline HSPF. While 7.1 is
a weighted average representing existing heating equipment types (ER and gas) for
retrofit projects where the true baseline is unknown. For new construction projects,the
baseline is the current building/energy code, 7.5.This alone does not fully describe all
the differences between expected and verified savings but is a systematic contributor to
the deviation.
o Split and Packaged Heat Pumps:The Evaluators were unable to determine how
expected savings were calculated. Using identical methodology to program planning
materials,the Evaluators calculated 'expected' savings which would yield near 100%
realization rates, but claimed savings estimates did not correspond with any known
method for determining savings. Simply put, claimed savings were roughly half the
results of using other methods.
■ The Site-Specific Program in total displays a realization rate of 97.2%with 5,185,350 kWh
verified electric energy savings in the Idaho service territory.
o SSOP_140807—Verified savings were measured with a whole-facility billing analysis.
Measured savings were lower than ex-ante savings. Discrepancies in savings could not
be traced because the implementer did not provide the calculations used to develop
initial savings estimates. Low RRs suggest either that occupant behavior has changed
since project implementation or that the initial analysis did not adequately capture the
relationship (or lack thereof) between energy usage and exterior temperature.
o SSOP_140225—A whole-facility billing analysis was completed and produced
statistically significant savings, however the estimates greatly exceeded expectations
(693.9%of expectations), or indeed what can reasonably be expected in savings from
Measurement and Evaluation Report 11

Avista Idaho PY2024
the refrigeration measures installed.This indicates the significant other changes, such as
additional equipment or changes in occupancy took place conflating results. The
evaluators examined projects documents and calculated prescriptive savings estimates
based on available data. While documentation did not provide the level of detail to fully
replicate expected savings,verification estimates were similar to and corroborated
claimed savings,thus the results of this project are considered to be 100% realization.
o SSLP_128331—An error in project record keeping assigned savings attributable only to
lighting HVAC savings (as a result of the reduced load on the HVAC system). These
misplaced savings artificially inflated savings expectations. While no other corrections
or changes were made, this lowered the verified savings to 59.7%.
o SSLP_111655—Expected savings for seven interior lighting line items could not be
exactly recreated, ranging between 98.5% and 104.4%of savings expectations. Using
verified input data,the Evaluators calculated savings to be 102.6%of expectations.
o SSOP_107281—The discrepancy in savings are likely a result of minor differences in
billing analysis specification (the Evaluators used linear regression, Implementer used
alternative method), and/or inputs: Historical weather data source (ADM used NOAA,
Implementer used alternative source), and normalization (ADM normalized usage to
TMYx data, Implementer did not perform any usage normalization). Verified savings are
108.9%of expectations.
o SSOP_82450—The discrepancy in motor replacement savings is likely due to the
inclusion of low-RPM data points from the raw SCADA data in the binning process.The
discrepancy in cooling blower savings is likely due to rounding. Combined,these
produce 96.8%of expected savings.
1.2.2 Recommendations
The following section details the Evaluator's recommendations resulting from the program evaluations
of the Residential Portfolio, Low-Income Portfolio, and Nonresidential Portfolio.
1.2.2.1 Residential Programs
The Evaluators offer the following recommendations regarding Avista's Residential electric programs:
■ The Evaluators found a handful of instances in which the rebated equipment did not meet the
program minimum requirements for efficiency or did not meet the measure specifications
defined by the RTF to achieve expected savings claimed by Avista.The Evaluators recommend
Avista check the source AHRI documentation and product level documentation to verify
efficiency prior to incentivizing installation of the measure and assigning expected savings.
■ In the Shell Program,the Evaluators recommend Avista assign window savings by square foot of
window rather than quantity of windows.Additionally, the Evaluators recommend Avista
incorporates expected heating type for window UES values in order to align with RTF projected
UES values.The Evaluators recommend that Avista ensure that the correct RTF UES values are
used to calculate expected savings and that Avista incorporate more granularity by climate zone,
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Avista Idaho PY2024
heating type, and U-value savings into Avista's TRM. In addition,the Evaluators identified many
discrepancies in the documentation provided in terms of square footage and unit quantity
verification which caused savings to deviate from 100%.The Evaluators recommend updating
the document data aggregation to ensure consistent values between the tracking database and
the provided rebate forms(primary heating type, heating and cooling zones).
■ In the Fuel Efficiency Program,the Evaluators recommend updating the Avista tracking
database to capture previous heating types for conversion measures and requiring home
previous heating type, existing cooling type, and home type as inputs on the rebate application
forms. Furthermore,Avista should review the AHRI AFUE reported values to make sure the
equipment qualifies for savings, and lastly enforce required document submission for all
rebates, such as the AHRI documentation or full model number are reported for all measures.
■ In the ENERGY STAR Homes Program,the Evaluators found that realization rates differed from
100%due to the application of heating zone and cooling zone via the RTF,which the Avista TRM
lacks.The Evaluators recommend updating the Avista TRM to match the primary heating type
for dual fuel households and heating/cooling zones reflected in the RTF workbooks.
■ In the Appliances Program, one sampled smart thermostat rebate included equipment that did
not meet RTF measure specifications to receive verified savings through the RTF workbooks,
which the Avista TRM savings values are drawn from.The Evaluators recommend providing a
qualified product list for customers to ensure purchased smart thermostats meet program
requirements. In addition,the Evaluators recommend Avista review program documentation to
verify qualifications after rebates are submitted.
■ For the Midstream Program,the Evaluators concluded that the implementers correctly
estimated expected savings values for a portion of the projects and incorrectly defined above
market practice efficiency baseline for a portion of projects, leading to a realization rate larger
than 100%.The Evaluators recommend incorporating appropriate baselines for each project,
reflecting the RTF market practice baseline present in the project installation year.
1.2.2.2 Low-Income Programs
The Evaluators do not offer any recommendations for Avista's PY2024 Low-Income electric program.
1.2.2.3 Nonresidential Programs
The Evaluators offer the following recommendations for Avista's Nonresidential electric programs:
■ Within the Prescriptive Lighting Program,the Evaluators recommend collecting space HVAC
configuration information and use interactive HVAC effects factors when calculating prescriptive
lighting savings for interior spaces, as well as incorporating in-service rates specific to lamp type.
■ For the Small Business Lighting Program, expected savings for occupancy sensors should be
calculated using a different algorithm to avoid the slight double counting of savings.
■ Within the Shell Program, both facility heating and cooling equipment information should be
included in tracking data. Instances of gas-heated buildings with electric AC should be noted.
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Avista Idaho PY2024
2-General Methodology
The Evaluators performed an impact evaluation on each of the programs summarized in Table 1-4.The
Evaluators used the following approaches to calculate energy impact defined by the International
Performance Measurement and Verification Protocols (IPMVP)' and the Uniform Methods Project
(UMP)z:
■ Document verification (review project documentation)
■ Deemed savings (RTF UES and Avista TRM values)
■ Whole facility billing analysis (IPMVP Option Q
■ Appropriate IPMVP Option (for Site-Specific, depending on project)
The Evaluators completed the above impact tasks for each the electric impacts and the natural gas
impacts for projects completed in the Idaho Avista service territory.
The M&V methodologies are program-specific and determined by previous Avista evaluation
methodologies as well as the relative contribution of a given program to the overall energy efficiency
impacts. Besides drawing on IPMVP,the Evaluators also reviewed relevant information on
infrastructure,framework, and guidelines set out for EM&V work in several guidebook documents that
have been published over the past several years.These include the following:
■ Northwest Regional Technical Forum (RTF)'
■ National Renewable Energy Laboratory (NREL), United States Department of Energy (DOE) The
Uniform Methods Project (UMP): Methods for Determining Energy Efficiency Savings for Specific
Measures,April 2013'
■ International Performance Measurement and Verification Protocol (IPMVP) maintained by the
Efficiency Valuation Organization(EVO)with sponsorship bythe U.S. Department of Energy(DOE)'
The Evaluators kept data collection instruments, calculation spreadsheets, and monitored/survey data
available for Avista records.
2.1 Glossary of Terminology
As a first step to detailing the evaluation methodologies,the Evaluators have provided a glossary of
terms to follow:
■ Deemed Savings—An estimate of an energy savings outcome (gross savings)for a single unit of
an installed energy efficiency measure.This estimate (a) has been developed from data sources
1 https://www.nrel.gov/docs/fy02osti/31505.pdf
2 https://www.nrel.gov/docs/fyl8osti/70472.pdf
3 https://rtf.nwcouncil.org/measures
4 Notably,The Uniform Methods Project(UMP) includes the following chapters authored by ADM. Chapter 9 (Metering Cross-
Cutting Protocols)was authored by Dan Mort and Chapter 15(Commercial New Construction Protocol)was Authored by Steven
Keates.
5 Core Concepts: International Measurement and Verification Protocol.EVO 100000—1:2016,October 2016.
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Avista Idaho PY2024
and analytical methods that are widely accepted for the measure and purpose and (b) are
applicable to the situation being evaluated.
■ Expected Savings—Calculated savings used for program and portfolio planning purposes.
■ Adjusted Savings—Savings estimates after database review and document verification has been
completed using deemed unit-level savings provided in the Avista TRM. It adjusts for such
factors as data errors and installation rates.
■ Verified Savings—Savings estimates after the unit-level savings values have been updated and
energy impact evaluation has been completed, integrating results from billing analyses and
appropriate RTF UES and Avista TRIM values.
■ Gross Savings—The change in energy consumption directly resulting from program-related
actions taken by participants in an efficiency program, regardless of why they participated.
■ Free Rider—A program participant who would have implemented the program measure or
practice in absence of the program.
■ Net-To-Gross—A factor representing net program savings divided by gross program savings that
is applied to gross program impacts to convert them into net program load impacts.
■ Net Savings—The change in energy consumption directly resulting from program-related
actions taken by participants in an efficiency program,with adjustments to remove savings due
to free ridership.
■ Non-Energy Benefits—Quantifiable impacts produced by program measures outside of energy
savings (comfort, health and safety, reduced alternative fuel, etc.).
■ Non-Energy Impacts—Quantifiable impacts in energy efficiency beyond the energy savings
gained from installing energy efficient measures (reduced cost for operation and maintenance
of equipment, reduced environmental and safety costs, etc.).
2.2 Summary of Approach
This section presents our general cross-cutting approach to accomplishing the impact evaluation of
Avista's Residential, Low-Income, and Nonresidential programs listed in Table 1-4.This section is
organized by general task due to the methodological overlap across programs.
The Evaluators outline the approach to verifying, measuring, and reporting the portfolio impacts and
summarizing potential program and portfolio improvements.The primary objective of the impact
evaluation is to determine ex-post verified net energy savings. On-site verification and was conducted
during this impact evaluation for site-specific projects.
Our general approach for this evaluation considers the cyclical feedback loop among program design,
implementation, and impact evaluation. Our activities during the evaluation estimate and verify annual
energy savings and identify whether a program is meeting its goals.These activities are aimed to provide
guidance for continuous program improvement and increased cost effectiveness for the 2024 and 2025
program years.
The Evaluators employed the following approach to complete impact evaluation activities for the
programs.The Evaluators define major approaches to determining net savings for Avista's programs:
■ A Deemed Savings approach involves using stipulated savings for energy conservation measures
for which savings values are well-known and documented. These prescriptive savings may also
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Avista Idaho PY2024
include an adjustment for certain measures, such as lighting measures in which site operating
hours may differ from RTF values.
■ A Billing Analysis approach involves estimating energy savings by applying a linear regression to
measured participant energy consumption utility meter billing data. Billing analyses included
billing data from nonparticipant customers.This approach does not require on-site data collection
for model calibration.This approach aligns with the IPMVP Option C.
■ A Semi-Custom approach, used for the Prescriptive Lighting program,where savings are
quantified by a standard engineering algorithm with key performance parameter(s), such as
pre/post wattage, quantity and annual hours of use.This approach aligns with IPMVP Option A.
■ A Custom approach, used for the Site-Specific program involves selecting the appropriate IPMVP
option to apply to the specific measure or project. Typically, this is Option A, as most projects in
the program are lighting retrofits,however Options B,C and D are also employed,depending upon
the project. Specific methods are discussed in each site report.
The Evaluators accomplished the following quantitative goals as part of the impact evaluation:
■ Verify savings with 10% precision at the 90%confidence level;
■ Where appropriate, apply the RTF to verify measure impacts; and
■ Where available data exists,conduct billing analysis with a suitable comparison group to estimate
measure savings.
■ Used IPMVP analysis methods for custom projects.
For each program,the Evaluators calculated adjusted savings for each measure based on the Avista TRM
and results from the database review.The Evaluators calculated verified savings for each measure based
on the RTF UES,Avista TRM, or billing analysis in combination with the results from document review.
Reported Database Adjusted Document-' Evaluate
Savings Review savings Review Savings
The Evaluators assigned methodological rigor level for each measure and program based on its
contribution to the portfolio savings and availability of data.
The Evaluators analyzed billing data for all electric measures with sufficient PY2024 participation data to
identify savings effects.The Evaluators applied billing analysis results to determine evaluated savings
only for measures where savings could be isolated (that is,where a sufficient number of participants
could be identified who installed only that measure). The following subsection outlines the specific
regression equations used as a part of these billing analyses.
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2.2.1 Database Review
At the outset of the evaluation, the Evaluators reviewed the databases to ensure that each program
tracking database conforms to industry standards and adequately tracks key data required for
evaluation.
Measure-level net savings were evaluated primarily by reviewing measure algorithms and values in the
tracking system to assure that they are appropriately applied using the Avista TRM.The Evaluators then
aggregated and cross-checked program and measure totals.
The Evaluators reviewed program application documents for a sample of incented measures to verify
the tracking data accurately represents the program documents.The Evaluators ensured the home
installed measures that meet or exceed program efficiency standards.
2.2.2 Verification Methodology
In this section,the Evaluators summarize the verification methods used to ensure project-level details
were indeed completed and to the efficiency levels detailed in the program-level tracking data.
The Evaluators summarize the methods for each verification effort:
■ Sampling methodology for most programs
■ Sampling methodology for the Site-Specific Program
■ Document-based verification
■ Survey-based verification
■ On-site visits
2.2.2.1 Sampling Methodology for Most Programs
The Evaluators verified a sample of participating households for detailed review of the installed measure
documentation and development of verified savings.The Evaluators verified tracking data by reviewing
invoices and surveying a sample of participant customer households. The Evaluators also conducted a
verification survey for program participants.
The Evaluators used the following equations to estimate sample size requirements for each program and
fuel type. Required sample sizes were estimated as follows:
Equation 2-1:Sample Size for Infinite Sample Size
n _ (Z x CV Z
ld )
Equation 2-2:Sample Size for Finite Population Size
n
no = Cl
1 + Nl
Where,
■ n =Sample size
■ Z = Z-value for a two-tailed distribution at the assigned confidence level.
■ CV= Coefficient of variation
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Avista Idaho PY2024
■ d = Precision level
■ N = Population
For a sample that provides 90/10 precision,Z= 1.645 (the critical value for 90%confidence) and d=0.10
(or 10% precision).The remaining parameter is CV, or the expected coefficient of variation of measures
for which the claimed savings may be accepted. A CV of.5 was assumed for residential programs due to
the homogeneity of participation',which yields a sample size of 68 for an infinite population. Sample
sizes were adjusted for smaller populations via the method detailed in Equation 2-2.
The following sections describe the Evaluator's methodology for conducting document-based
verification and survey-based verification.
2.2.2.2 Sampling Methodology for the Site-Specific Program
For the Site-Specific program, Simple Random Sampling is not an effective sampling methodology as the
CV values observed in business programs are typically very high because the distributions of savings are
generally positively skewed. Often, a relatively small number of projects account for a high percentage
of the estimated savings for the program.
To address this situation, we use a sample design for selecting projects for the M&V sample that
considers such skewness. With this approach, we select several sites with large savings for the sample
with certainty and take a random sample of the remaining sites.To improve the precision, non-certainty
sites are selected for the sample through systematic random sampling.That is, a random sample of sites
remaining after the certainty sites have been selected is selected by ordering them according to the
magnitude of their savings and using systematic random sampling. Sampling systematically from a list
that is ordered according to the magnitude of savings ensures that any sample selected will have some
units with high savings, some with moderate savings, and some with low savings. Specific sampling
characteristics are shown in the Site-Specific section of this report.
The following sections describe the Evaluator's methodology for conducting document-based
verification and survey-based verification.
2.2.2.3 Document-Based Verification
The Evaluators requested rebate documentation for a subset of participating customers.These
documents included invoices, rebate applications, pictures, and AHRI certifications for the following
programs.
■ Shell Program (res)
■ Fuel Efficiency Program
■ ENERGY STAR° Homes Program
■ Appliances Program
■ Midstream Program (res)
6 Assumption based off California Evaluation Framework:
https://www.cpuc.ca.gov/uploaded Files/CPUC_Public_Website/Content/Utilities_and_I ndustries/Energy/Energy_Programs/De
mand_Side_Management/EE_and_Energy_Savings_Assist/CAEvaluationFramework.pdf
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Avista Idaho PY2024
Prescriptive Lighting Program
Small Business Lighting Program
HVAC Program (non-res)
Grocer
Shell Program (non-res)
Midstream Program (non-res)
Site-Specific
This sample of documents was used to cross-verify tracking data inputs. In the case the Evaluators found
any deviations between the tracking data and application values, the Evaluators reported and
summarized those differences in the Database Review sections presented for each program in Section
3.2, Section 4.1, and Section 5.3.
The Evaluators developed a sampling plan that achieves a sampling precision of±10% at 90%statistical
confidence—or"90/10 precision"—to estimate the percentage of projects for which the claimed savings
are verified or require some adjustment.
The Evaluators developed the following samples for each program's document review using Equation
2-1 and Equation 2-2.The Evaluators ensured representation in each state and fuel type for each
measure.
Table 2-1:Document-based Verification Samples and Precision by Program
Sector Drogram Electric (With Finite Precision at
7— Population Population •0' Cl
Residential Shell 199 51 90%±9.96%
Residential Fuel Efficiency 15 14 90%±5.88%
Residential ENERGY STAR® Homes 26 20 90%±9.01%
Residential Appliances 606 77 90%±8.76%
Residential Midstream 402 402 90%±0.00%
Low-Income Low-Income 8 NA NA
Nonresidential Prescriptive Lighting 417 324 90%±9.94%
Nonresidential Small Business Lighting 618 410 90%±10.85%
Nonresidential HVAC 2 2 90%±0.00%
Nonresidential Grocer 15 15 90%±0.00%
Nonresidential Shell 7 7 90%±0.00%
Nonresidential Midstream 86 86 90%±0.00%
Nonresidential Site-Specific 1 18 1 11 1 90%±8.14%
*Assumes sample size of 68 for an infinite population,based on CV(coefficient of variation)=0.5,
d(precision)=10%,Z(critical value for 90%confidence)=1.645.
The table above represents the number of rebates in Idaho service territory only(does not include
Washington rebate samples). The Evaluators ensured representation of state and fuel type in the
sampled rebates for document verification.
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Avista Idaho PY2024
2.2.2.4 Survey-Based Verification
The Evaluators conducted survey-based verification in PY2023. Due to change in process evaluation
cadence,the Evaluators utilized the response results from PY2023 in the PY2024 impact evaluation
efforts. A process evaluation, including surveys, will be completed in PY2025 for all programs.
The primary purpose of conducting a verification survey is to confirm that the measure was installed and
is still currently operational and whether the measure was early retirement or replace-on-burnout.
for the Residential Fuel Efficiency, Residential Appliance, and Nonresidential Lighting Programs for the
Idaho Electric Avista projects.The Evaluators developed a sampling plan that achieved a sampling
precision of±6.81% at 90%statistical confidence for residential ISRs estimates at the measure-level
during web-based survey verification. The Evaluators developed a sampling plan that achieved a
sampling precision of±36.59%at 90%statistical confidence for non-residential ISRs estimates at the
measure-level during web-based survey verification.
Table 2-2: Survey-Based Verification Sample and Precision by Program
Residential Fuel Efficiency* 28 5 90%±33.95%
Residential Appliances 556 112 90%±6.95%
Non-Residential Prescriptive Lighting 379 5 90%±36.59%
Total 1,299 176 90%±6.96%
*These programs did not meet 90/10 precision for the survey-based verification.
For these programs,100%in-service rates were assumed.
The Evaluators implemented a web-based survey to complete the verification surveys.The Evaluators
contacted all customers in the programs listed in the table above with the goal of reaching 90/10
precision, however, all efforts were exhausted to reach these customers and therefore these programs
do not display 90/10 precision at the program-level for in-service rate calculations. For programs in
which this goal was not met,the Evaluators assumed in-service rates of 100%.
The findings from these activities served to estimate ISRs for each measure surveyed.These ISRs were
applied to verification sample desk review rebates towards verified savings, which were then applied to
the population of rebates.The measure-level ISRs resulting from the survey-based verification are
summarized in Section 3.1.
2.2.2.5 On-Site Visits
For sampled projects in the Site-Specific program,the Evaluators conducted onsite visits to the facilities
to verify installation, collected facility characteristics and collected any data needed to conduct savings
calculations. In Idaho, a total of four visits were conducted to verify electric measures. Further details
are available in the Site-Specific chapter.
2.2.3 Impact Evaluation Methodology
The Evaluators employed the following approach to complete impact evaluation activities for the
programs.The Evaluators define two major approaches to determining net savings for Avista's
programs:
■ Deemed Savings
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Avista Idaho PY2024
■ Billing Analysis (IPMVP Option Q
The Site-Specific program also employed various IPMVP options, deepening upon the project and
measure, and is discussed separately as it differs in approach from the approaches used in the
remainder of the portfolio. In the following sections,the Evaluators summarize the general guidelines
and activities followed to conduct each the deemed savings and billing analyses approaches above.
In the following sections, the Evaluators summarize the general guidelines and activities followed to
conduct each of the above analyses.
2.2.3.1 Deemed Savings
This section summarizes the deemed savings analysis method the Evaluators employed for the
evaluation of a subset of measures for each program.The Evaluators completed the validation for
specific measures across each program using the RTF unit energy savings (UES)values, where available.
The Evaluators ensured the proper measure unit savings were recorded and used in the calculation of
Avista's ex-ante measure savings.The Evaluators requested and used the technical reference manual
Avista employed during calculation of ex-ante measure savings (Avista TRM).The Evaluators
documented any cases where recommended values differed from the specific unit energy savings
workbooks used by Avista.
In cases where the RTF has existing unit energy savings (UES) applicable to Avista's measures,the
Evaluators verified the quantity and quality of installations and applied the RTF's UES to determine
verified savings.
2.2.3.2 Billing Analysis
This section describes the billing analysis methodology employed by the Evaluators as part of the impact
evaluation and measurement of energy savings for measures with sufficient participation.The
Evaluators performed billing analyses with a matched control group and utilized a quasi-experimental
method of producing a post-hoc control group. In program designs where treatment and control
customers are not randomly selected at the outset, such as for downstream rebate programs, quasi-
experimental designs are required.
For the purposes of this analysis, a household is considered a treatment household if it has received a
program incentive. Additionally, a household is considered a control household if the household has not
received a program incentive.To isolate measure impacts, treatment households are eligible to be
included in the billing analysis if they installed only one measure during the 2024 program year. Isolation
of individual measures is necessary to provide valid measure-level savings. Households that installed
more than one measure may display interactive energy savings effects across multiple measures that
are not feasibly identifiable.Therefore, instances where households installed isolated measures are
used in the billing analyses. In addition,the pre-period identifies the period prior to measure installation
while the post-period refers to the period following measure installation.
The Evaluators utilized propensity score matching (PSM) to match nonparticipants to similar participants
using pre-period billing data. PSM allows the Evaluators to find the most similar household based on the
customers' billed consumption trends in the pre-period and verified with statistical difference testing.
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After matching based on these variables,the billing data for treatment and control groups are
compared, as detailed in IPMVP Option C.The Evaluators fit regression models to estimate weather-
dependent daily consumption differences between participating customer and nonparticipating
customer households.
Cohort Creation
The PSM approach estimates a propensity score for treatment and control customers using a logistic
regression model.A propensity score is a metric that summarizes several dimensions of household
characteristics into a single metric that can be used to group similar households.The Evaluators created
a post-hoc control group by compiling billing data from a subset of nonparticipants in the Avista territory
to compare against treatment households using quasi-experimental methods.This allowed the
Evaluators to select from a large group of similar households that have not installed an incented
measure. With this information, the Evaluators created statistically valid matched control groups for
each measure via seasonal pre-period usage.The Evaluators matched customers in the control group to
customers in the treatment group based on nearest seasonal pre-period usage (e.g., summer,spring,
fall, and winter) and exact 3-digit zip code matching (the first three digits of the five-digit zip code). After
matching,the Evaluators conducted a t-test for each month in the pre-period to help determine the
success of PSM.
While it is not possible to guarantee the creation of a sufficiently matched control group,this method is
preferred because it is likely to have more meaningful results than a treatment-only analysis. Some
examples of outside variables that a control group can sufficiently control for are changes in economies
and markets, large-scale social changes, or impacts from weather-related anomalies such as flooding or
hurricanes.
After PSM,the Evaluators ran the following regression models for each measure:
■ Fixed effect Difference-in-Difference (D-n-D) regression model (recommended in UMP
protocols)'
■ Random effects post-program regression model (PPR) (recommended in UMP protocols)
■ Gross billing analysis (treatment only)
The second model listed above (PPR) was selected because it had the best fit for the data, identified
using the adjusted R-squared. Further details on regression model specifications can be found below.
Data Collected
The following lists the data collected for the billing analysis:
1. Monthly billing data for program participants (treatment customers)
2. Monthly billing data for a group of non-program participants (control customers)
3. Program tracking data, including customer identifiers, address, and date of measure installation
7 National Renewable Energy Laboratory(NREL)Uniform Methods Project(UMP)Chapter 17 Section 4.4.7.
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4. National Oceanic and Atmospheric Administration (NOAA) weather data between January 1,
2023 and December 31, 2024)
5. Typical Meteorological Year(TMY3) data
Billing and weather data were obtained for program year 2024 and for one year prior to measure install
dates (2023).
Weather data was obtained from the nearest weather station with complete data during the analysis
years for each customer by mapping the weather station location with the customer zip code.
TMY weather stations were assigned to NOAA weather stations by geocoding the minimum distance
between each set of latitude and longitude points.This data is used for extrapolating savings to long-
run, 30-year average weather.
Data Preparation
The following steps were taken to prepare the billing data:
1. Gathered billing data for homes that participated in the program.
2. Excluded participant homes that also participated in the other programs, if either program
disqualifies the combination of any other rebate or participation.
3. Gathered billing data for similar customers that did not participate in the program in evaluation.
4. Excluded bills missing address information.
5. Removed bills missing fuel type/Unit of Measure (UOM).
6. Removed bills missing usage, billing start date, or billing end date.
7. Remove bills with outlier durations (<9 days or>60 days).
8. Excluded bills with consumption indicated to be outliers.
9. Remove duplicate bills and any bills with overlapping billing periods. If two billing periods
overlapped,the bill with a start date that matched the previous bill's end date was included and
the other bill was excluded. For example, if overlapping bill 1 had a 02/19/2024 start date,
overlapping bill 2 had a 02/25/2024 start date, and the previous bill had a 02/19/2024 end date,
overlapping bill 2 would be removed. If there was no previous bill,the overlapping bill with the
earlier start date was included and the other overlapping bill was removed.
10. Calendarized bills (recalculates billing dates, usage, and total billed days such that bills begin and
end at the start and end of each month).
11. Obtained weather data from nearest NOAA weather station using 5-digit zip code per
household.
12. Computed Heating Degree Days (HDD) and Cooling Degree Days (CDD)for a range of setpoints.
The Evaluators assigned a setpoint of 65°F for both HDD and CDD.The Evaluators tested and
selected the optimal temperature base for HDDs and CDDs based on model R-squared values.
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Avista Idaho PY2024
13. Removed measure cohorts without at least 75 treatment customers.
14. Selected treatment customers with only one type of measure installation during the analysis
years and combined customer min/max install dates with billing data (to define pre-and post-
periods).
15. Restricted to treatment customers with install dates in specified range (typically January 1, 2024
through June 30, 2024)to allow for sufficient post-period billing data.
16. Restricted to control customers with usage less than or equal to two times the maximum
observed treatment group usage.This has the effect of removing control customers with
incomparable usage relative to the treatment group.
17. Removed customers with incomplete post-period bills (normally<6 months).
18. Removed customers with incomplete pre-period bills.
19. Restricted control customers to those with usage that was comparable with the treatment
group usage.
20. Created a matched control group using PSM and matching on pre-period seasonal usage and zip
code.
Regression Models
The Evaluators ran the following models for matched treatment and control customers for each
measure with sufficient participation. For net savings,the Evaluators selected either Model 1 or Model
2. The model with the best fit (highest adjusted R-squared) was selected.The Evaluators utilized Model
3 to estimate gross energy savings.
Model 1:Fixed Effects Difference-in-Difference Regression Model
The following equation displays the first model specification to estimate the average daily savings due to
the measure.
Equation 2-3:Fixed Effects Difference-in-Difference (D-n-D)Model Specification
sADCit = ao +f31(Post)it +MPost x Treatment)it +f33(HDD)it +f34(CDD)it +
f E;(Post x HDD)it +&(Post x CDD)it +97(Post x HDD x Treatment)it + MPost x CDD x
Treatment)it +f39(Month)t +f310(Customer Dummy)i + Eit
Where,
■ i=the ith household
■ t=the first, second,third, etc. month of the post-treatment period
■ ADCit =Average daily usage reading t for household i during the post-treatment period
■ Postit =A dummy variable indicating pre-or post-period designation during period t
at home i
■ Treatmenti =A dummy variable indicating treatment status of home i
■ HDDit =Average heating degree days (base with optimal Degrees Fahrenheit) during
period t at home i
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■ CDDit =Average cooling degree days (base with optimal Degrees Fahrenheit) during period
t at home i (if electric usage)
■ Montht=A set of dummy variables indicating the month during period t
■ Customer Dummyi =a customer-specific dummy variable isolating individual household
effects
■ Eit =The error term
■ ao=The model intercept
■ #1_10 = Coefficients determined via regression
The Average Daily Consumption (ADC) is calculated as the total monthly billed usage divided by the
duration of the bill month.F'2 represents the average change in daily baseload in the post-period
between the treatment and control group and f37 and f3$ represent the change in weather-related daily
consumption in the post-period between the groups.Typical monthly and annual savings were
estimated by extrapolating the f37 and N coefficients with Typical Meteorological Year(TMY) HDD and
CDD data. However, in the case of gas usage, only the coefficient for HDD is utilized because CDDs were
not included in the regression model.
The equation below displays how savings were extrapolated for a full year utilizing the coefficients in the
regression model and TMY data.TMY data is weighted by the number of households assigned to each
weather station.
Equation 2-4:Savings Extrapolation
Annual Savings = F'2 * 365.25 +f37 * TMY HDD +f38 * TMY CDD
Model 2:Random Effects Post-Program Regression Model
The following equation displays the second model specification to estimate the average daily savings
due to the measure.The post-program regression (PPR) model combines both cross-sectional and time
series data in a panel dataset.This model uses only the post-program data,with lagged energy use for
the same calendar month of the pre-program period acting as a control for any small systematic
differences between the treatment and control customers; in particular, energy use in calendar month t
of the post-program period is framed as a function of both the participant variable and energy use in the
same calendar month of the pre-program period.The underlying logic is that systematic differences
between treatment and control customers will be reflected in the differences in their past energy use,
which is highly correlated with their current energy use. These interaction terms allow pre-program
usage to have a different effect on post-program usage in each calendar month.
The model specification is as follows:
Equation 2-5:Post-Program Regression (PPR)Model Specification
ADCit = a0 +f31(Treatment)i +F'2 (PreUsageSpring)i +f33(PreUsageSummer)i
+f34(PreUsageFall)i +f35(Pre Usage Winter)i + &(Month)t
+f37(Month x PreUsageSpring)it +f38(Month x PreUsageSummer)it
+f39(Month x PreUsageFall)it +#10(Month x PreUsageWinter)it +Q11(HDD)it
+f312(CDD)it +f313(Treatment x HDD)it +f314(Treatment x CDD)it + Eit
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Avista Idaho PY2024
Where,
■ i=the ith household
■ t=the first, second,third, etc. month of the post-treatment period
■ ADCit =Average daily usage for reading t for household i during the post-treatment period
■ Treatmenti =A dummy variable indicating treatment status of home i
■ Montht = Dummy variable indicating month of month t
■ PreUsageSpringl =Average daily usage in the spring months across household is available
pre-treatment billing reads
■ PreUsageSummerl = Average daily usage in the summer months across household is
available pretreatment billing reads
■ PreUsageFalli = Average daily usage in the fall months across household is available
pretreatment billing reads
■ PreUsageWinter1 =Average daily usage in the winter months across household is available
pre-treatment billing reads
■ HDDIt = Average heating degree days (base with optimal Degrees Fahrenheit) during
period t at home i
■ CDDIt =Average cooling degree days (base with optimal Degrees Fahrenheit) during period t
at home i (if electric usage)
■ £it = Customer-level random error
■ ao=The model intercept for home i
■ F'1_14 = Coefficients determined via regression
The coefficient f31 represents the average change in consumption between the pre-period and post-
period for the treatment group and N13 and f314 represent the change in weather-related daily
consumption in the post-period between the groups.Typical monthly and annual savings were
estimated by extrapolating the 913 and N14 coefficients with Typical Meteorological Year(TMY) HDD and
CDD data.
The equation below displays how savings were extrapolated for a full year utilizing the coefficients in the
regression model and TMY data.
Equation 2-6:Savings Extrapolation
Annual Savings = f31 * 365.25 +f311 * TMY HDD +f312 * TMY CDD
Model 3:Gross Billing Analysis, Treatment-Only Regression Model
The sections above detail the Evaluator's methodology for estimating net energy savings for each
measure.The results from the above methodology report net savings due to the inclusion of the
counterfactual comparison group. However, if sufficient non-participant data is not available to develop
a valid control group, gross savings can also be calculated via a treatment-only regression.This analysis
does not include control group billing data and therefore models energy reductions between the pre-
period and post-period for the measure participants (treatment customers).
To calculate the impacts of each measure, the Evaluators applied linear fixed effects regression using
participant billing data with weather controls in the form of Heating Degree Days (HDD) and Cooling
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Avista Idaho PY2024
Degree Days(CDD).The following equation displays the model specification to estimate the average
daily savings due to the measure.
Equation 2-7: Treatment-Only Fixed Effects Weather Model Specification
ADCit = ao +/31(Post)it +f32(HDD)it +f33(CDD)it +fl4(Post x HDD)it +fls(Post x CDD)it
+&(Customer Dummy)i +fl7(Month)t + Fit
Where,
■ i=the ith household
■ t=the first, second,third, etc. month of the post-treatment period
■ ADCit =Average daily usage for reading t for household i during the post-treatment period
■ HDDit = Average heating degree days (base with optimal Degrees Fahrenheit) during
period t at home i
■ CDDit =Average cooling degree days (base with optimal Degrees Fahrenheit) during period t
at home i(if electric usage)
■ Postit = A dummy variable indicating pre- or post-period designation during period t at
home i
■ Customer Dummyi = a customer-specific dummy variable isolating individual household
effects
■ ,-it = Customer-level random error
■ ao=The model intercept for home i
■ F'1_7 = Coefficients determined via regression
The results of the treatment-only regression models are gross savings estimates. If billing data for
statistically comparable control customers (i.e., non-participant Avista customers with comparable
usage to treatment customers) is not available, such gross savings analyses can provide reliable savings
estimates. While treatment-only models may not separate out the effects of national or regional events
like a pandemic or recession,they still provide meaningful estimates of changes in energy usage
associated with measure installation. Given that the COVID-19 pandemic is unlikely to dramatically
affect customer energy usage as of PY2024,treatment-only models can provide valid estimates of the
savings associated with many energy efficiency measures.
2.2.3.3 Net-To-Gross
The Northwest RTF UES measures do not require NTG adjustments as they are built into the deemed
savings estimates. In addition, billing analyses with counterfactual control groups, as proposed in our
impact methodology, does not require a NTG adjustment, as the counterfactual represents the
efficiency level at current market (i.e.the efficiency level the customer would have installed had they
not participated in the program).
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Avista Idaho PY2024
3. Residential Impact Evaluation Results
The Evaluators completed an impact evaluation on Avista's Residential portfolio to verify program-level
and measure-level energy savings for PY2024. The following sections summarize findings for each
electric impact evaluation in the Residential Portfolio in the Idaho service territory.The Evaluators used
data collected and reported in the tracking database, online application forms, Avista TRM, RTF, and
billing analysis of participants and nonparticipants to evaluate savings.This approach provided the
strongest estimate of achieved savings practical for each program,given its delivery method, magnitude
of savings, number of participants, and availability of data.Table 3-1 summarizes the residential verified
impact savings by program.
Table 3-1: Residential Verified Impact Savings by Program
Expected Savings(kWh) Verified Savings(kWh) Verified Realization
Rate
Shell 189,0092.17 214,109.62 I 113.23%
Fuel Efficiency 105,612.00 103,207.00 97.72%
ENERGY STAR Homes 85,018.00 77,951.08 91.69%
Appliances 150,143.00 94,924.43 63.22%
Midstream 1,492,479.09 1,891,167.23 126.71%
Home Energy Audit NA 9,418.03 NA
I_Total Res 2,022,344.26 2,390,777.39 118.22%
In PY2024,Avista completed and provided incentives for residential electric measures in Idaho and
reported total electric energy savings of 2,022,344.26 kWh. All programs met savings goals based on
reported savings, leading to an overall achievement of 2,390,777.39 kWh leading to a realization rate of
118.22%for the residential programs. Excluding the Home Energy Audit program, which did not have an
expected savings estimate,Avista's Idaho PY2024 residential electric measures yielded savings of
2,381,359.36 for a 117.75% realization rate. Further details of the impact evaluation results by program
are provided in the sections following.
3.1 Simple Verification Results
The Evaluators surveyed 2,229 unique customers that participated in Avista's residential energy
efficiency program in October 2022 and March 2023 using an email survey approach.The Evaluators did
not complete surveying efforts in the PY2024 evaluation and therefore referenced simple verification
responses from the PY2023 impact evaluation.
Customers with a valid email were sent the survey via an email invitation. The Evaluators surveyed
customers that received rebates for Water Heat, HVAC, Small Home & MF Weatherization,Appliance,
and Midstream Programs in PY2023. For the purposes of this report,the results for the Fuel Efficiency
and Appliance Programs are summarized.
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Avista Idaho PY2024
Table 3-2:Summary of Survey Response Rate
Population Respondents
Initial email contact list 8,262
Invalid or bounced 416
Invalid or bounced email(%) 5.0%
Invitations sent(unique valid) 7,846
Completions 2,229
Response rate(%) 28.4%
3.1.1 In-Service Rates
The Evaluators calculated in-service rates of installed measures from simple verification surveys
deployed to program participants for the Fuel Efficiency and Appliances Programs. The Evaluators asked
participants if the rebated equipment is currently installed and working, in addition to questions about
the new equipment fuel type. The Evaluators achieved ±6.81% precision across the programs surveyed
for the electric measures in Avista's service territory, summarized in Table 3-3.
Table 3-3:State-Specific Simple Verification Precision by Program
Program11W State-Specific State-Specific State-Specific
Sector •0'
Population Respondents
Residential Fuel Efficiency* 28 5 90%±33.95%
Residential Appliances 556 112 90%±6.95%
Total 920 171 90%±6.81%
*These programs did not achieve 90/10 precision. However,responses indicated 100%ISRs
Table 3-4: Mixed State-Specific Simple Verification Precision by Program
RespondentsNed State- Mixed State- Mixed State-
Sec Program _W Specific Specific Specific Precision
tor IV Population
.0• Cl
Residential Fuel Efficiency 28 5 90%±33.95%
Residential Appliances 1,688 298 90%±4.32%
Total 2,767 446 90%±4.29%
*These programs did not achieve 90/10 precision.However,responses indicated 100%ISRs
As previously stated, the Evaluators contacted all customers in the Fuel Efficiency Program, and
Appliances Program with the goal of reaching 90/10 precision, however, all efforts were exhausted to
reach these customers and therefore these programs do not display 90/10 precision at the program-
level for in-service rate calculations. For programs in which this goal was not met,the Evaluators either
assigned mixed-state (Idaho and Washington) in-service rates is precision meets the 90/10 goals, or
assumed in-service rates of 100% if the mixed-state responses did not meet the 90/10 goals.The state-
level (Idaho) and mixed state-level (Idaho and Washington) measure-level ISRs determined from the
verification survey for each program in which simple verification was conducted is presented in the
tables below.
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Avista Idaho PY2024
Table 3-5:Fuel Efficiency Program ISRs by Measure
RespondentsState-level State- Mixed State- Mixed ISR
Measure Methodologylevel State-
Respondents
E Electric To Natural Gas Furnace* 2 100% 2 100% Assume 100%
ISR
E Electric To Natural Gas Furnace& Assume 100%
Water Heat* 3 100% 3 100% ISR
*Due to lack of 90/10 precision,this ISR is instead assumed to be 100%
Table 3-6:Appliance Program ISRs by Measure
RespondentsMixed State- Mixed
Measure State-level State- level State-level ISR
.. . .•
Respondents ISIR
E Energy Star Certified State-specific
Refrigerator and Refrigerator- 41 100% 113 97% ISR
Freeze
E Energy Star Certified Upright 12 100% 22 100% State-specific
Freezer ISR
E Energy Star Rated Clothes Dryer 30 97% 81 99% State-specific
ISR
E Energy Star Rated Front Load 17 100% 48 100% State-specific
Washer ISR
E Energy Star Rated Top Load 8 100% 25 100% State-specific
Washer ISR
These ISR values were utilized in the desk reviews for each of the measures listed above in order to
calculate verified savings. Additional insights from the survey responses are summarized in Appendix B:
Summary of Survey Respondents.
3.2 Program-Level Impact Evaluation Results
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Residential sector in the section below.
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Avista Idaho PY2024
3.2.1 Shell Program
The Shell Program provides incentives to customers for improving the integrity of their home envelope
with upgrades to insulation, windows, and doors. Participating homes must have electric or natural gas
heating and itemized invoices including measure details such as insulation U-factors,window U-values,
or square footage. In order to be eligible for incentive,the single-family households, including fourplex
or less, must demonstrate an annual electricity usage of at least 8,000 kWh or an annual gas usage of at
least 340 Therms. Multifamily homes have no usage requirement. This program includes free
manufactured home duct sealing implemented by UCONS. Table 3-7 summarizes the measures offered
under this program.
Table 3-7:Shell Program Measures
Description Impact Analysis
Methodology
E Attic Insulation With Electric Heat Attic insulation for homes heated with electricity RTF UES
E Energy Star Certified Insulated Door Replace door with ENERGY STAR rated door in RTF UES
homes heated with electricity
E Floor Insulation With Electric Heat Floor insulation for homes heated with electricity RTF UES
E Sliding Glass Doors with Electric High efficiency sliding glass door replacement for RTF UES
Heat homes heated with electricity
E Wall Insulation With Electric Heat Wall insulation for homes heated with electricity RTF UES
E Window DIY Replc With Electric High-efficiency double pane window
Heating
replacement for homes heated with electricity RTF UES
installed by home owner
E Window Replc from Single Pane W High-efficiency double pane window
Electric Heat replacement for homes heated with electricity RTF UES
installed by contractor
E Multifamily Attic Insulation With
Electric Heat Attic insulation for homes heated with electricity RTF UES
E Multifamily Energy Star Certified Replace door with ENERGY STAR rated door in
Insulated Door homes heated with electricity RTF UES
E Multifamily Floor Insulation With
Electric Heat Floor insulation for homes heated with electricity RTF UES
E Multifamily Sliding Glass Doors with High efficiency sliding glass door replacement for
Electric Heat homes heated with electricity RTF UES
E Multifamily Wall Insulation With
Electric Heat Wall insulation for homes heated with electricity RTF UES
E Multifamily Window DIY Replc With High-efficiency double pane window
Electric Heating replacement for homes heated with electricity RTF UES
installed by home owner
E Multifamily Window Replc from High-efficiency double pane window
Single Pane W Electric Heat replacement for homes heated with electricity RTF UES
installed by contractor
The following table summarizes the adjusted and verified electric energy savings for the Shell Program
impact evaluation.
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Avista Idaho PY2024
Table 3-8:Shell Program Verified Electric Savings
PY2024 Expected Adjusted Verified Verified
Measure Participation Savings Savings Savings Realization
(kWh) (kWh) (kWh) Rate
E Attic Insulation With Electric Heat 16 27,955.80 27,955.80 15,084.71 53.96%
E Energy Star Certified Insulated Door 15 1,387.62 1,387.62 1,387.62 100.00%
E Floor Insulation With Electric Heat 6 3,543.15 3,543.15 3,744.67 105.69%
E Sliding Glass Doors with Electric 26 10,009.90 12,512.38 7,307.27 73.00%
Heat
E Wall Insulation With Electric Heat 8 13,822.88 14,708.05 15,490.63 112.07%
E Window DIY Replc With Electric 5 3,390.80 3,390.80 3,396.58 100.17%
Heating
E Window Replc from Single Pane W
94 95,740.50 80,310.83 61,357.77 64.09%
Electric Heat
E Multifamily Attic Insulation With 1 1,836.00 3,348.00 2,194.78 119.54%
Electric Heat
E Multifamily Energy Star Certified 0 0.00 0.00 0.00 0.00%
Insulated Door
E Multifamily Floor Insulation With 0 0.00 0.00 0.00 0.00%
Electric Heat
E Multifamily Sliding Glass Doors with 3 968.70 1,937.40 786.39 81.18%
Electric Heat
E Multifamily Wall Insulation With o
Electric Heat 0 0.00 0.00 0.00 0.00%
E Multifamily Window DIY Replc With 0 0.00 0.00 0.00 0.00%
Electric Heating
E Multifamily Window Replc from 25 30,436.82 28,357.44 103,359.20 339.59%
Single Pane W Electric Heat
Total 199 189,092.17 177,451.47 214,109.62 113.23%
The Shell Program displayed verified savings of 214,109.62 kWh with a realization rate of 113.23%
against the expected savings for the program. The following table summarizes the incentive costs
associated with the program.
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Avista Idaho PY2024
Table 3-9:Shell Program Incentive Costs by Measure
Measure Incentive Costs
E Attic Insulation With Electric Heat $11,272.50
E Energy Star Certified Insulated Door $1,800.00
E Floor Insulation With Electric Heat $3,851.25
E Sliding Glass Doors with Electric Heat $14,640.00
E Wall Insulation With Electric Heat $7,300.82
E Window DIY Replc With Electric Heating $2,520.00
E Window Replc from Single Pane W Electric Heat $96,094.20
E Multifamily Attic Insulation With Electric Heat $1,350.00
E Multifamily Energy Star Certified Insulated Door $0.00
E Multifamily Floor Insulation With Electric Heat $0.00
E Multifamily Sliding Glass Doors with Electric Heat $1,440.00
E Multifamily Wall Insulation With Electric Heat $0.00
E Multifamily Window DIY Replc With Electric Heating $0.00
E Multifamily Window Replc from Single Pane W Electric Heat $21,319.84
Total $161,588.61
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Shell Program in the section below.
3.2.1.1 Database Review& Verification
This section describes the Evaluator's database review and document verification findings for the Shell
Program.
Before conducting the impact analysis,the Evaluators conducted a database review for the Shell
Program.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Section 2.2.2.3.
The Evaluators used the Avista TRM to determine adjusted savings and RTF UES values for verified
savings.The Evaluators reviewed each measure number of units, square footage, and insulation where
available. The Evaluators found one instance of the window replacement measures in which window
quantity in the rebate application did not align with the values presented in the tracking data. The
Evaluators also had insufficient documentation to verify seven window replacement square footage
values. This contributed to deviations from a 100% realization rate.
The Evaluators found no duplicate rebates in the project data and therefore did not remove any rebates
from verified savings.
3.2.1.2 Verification Surveys
The Evaluators did not conduct verification survey activities as of PY2024 but per biennium planning
should conduct survey efforts for the Shell program in PY2025.
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Avista Idaho PY2024
3.2.1.3 Impact Analysis
This section summarizes the verified savings results for the Shell Program.The Evaluators calculated
verified savings for the electric measures using the RTF workbook in place at the time the savings goals
for the program was finalized.The Evaluators calculated adjusted savings for each measure using the
active Avista TRM values and verified tracking data.These LIES values were applied to a random sample
of participants, with verification of project documents such as rebate applications to verify installation,
quantity, and efficiency of the equipment.
3.2.1.4 Verified Savings
The Shell Program in total displays a realization rate of 113.23%with 214,109.62 kWh verified electric
energy savings in the Idaho service territory, as displayed in Table 3-8.
The realization rate for the electric savings in the Shell Program deviates from 100% due primarily to the
differences between the categories applied in the Avista TRM prescriptive savings values and the more
detailed categories present with unique RTF LIES values.The RTF differentiates envelope measure
savings based on household heating/cooling zone and heating type. In contrast,the Avista TRM applies a
single savings value for all customers based on an assumed distribution of customer household
characteristics.This assumed distribution seemed to inflate the electric savings associated with some
measures in PY2024, such as E Sliding Glass Doors with Electric Heat (73.00% RR) and E Window Replc
from Single Pane W Electric Heat (64.09% RR). Introducing more granular measure categories into the
Avista TRM that match those in the RTF LIES workbook may help improve realization rates in the future.
The Attic Insulation measure realization rate for single-family dwellings deviated from 100% because the
RTF assigns unit savings determined by heating zone and heating type.The RTF verified savings result in
per unit square footage kWh impacts between 0.52 and 2.16, while the Avista TRM assigns a value of
1.86 kWh per square foot, regardless of heating type.The realization rate deviates further because the
majority of homes that participated in attic insulation retrofits displayed zonal heating type.Therefore,
the average verified kWh saved per square foot among participants is closer to 0.6 than 1.86. The
Evaluators recommend Avista update the Avista TRM savings values to vary based on key household
characteristics like heating zone and heating type.
Lastly,the Evaluators found that the Avista TRM seems to calculate window savings based on the
quantity of windows installed as opposed to the square footage of windows. If assumptions regarding
the average square footage of installed windows are accurate this can be a valid methodology, but per-
quantity calculations (as opposed to per-square foot) seemed to underestimate multifamily window
savings, as evidenced by the 339.6% realization rate for the E Multifamily Window Replc from Single
Pane W Electric Heat measure.The Evaluators recommend that Avista consider calculating window
savings based on installed square footage and encourage customers to include that value in rebate
forms to simplify future savings calculations. Calculating window savings based on a per-square foot
value would also help the Avista TRM align more closely with the RTF single family weatherization LIES
workbook.'
8 https://rtf.nwcouncil.org/measure/single-family/
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Avista Idaho PY2024
3.2.2 Fuel Efficiency Program
The Residential Fuel Efficiency Program encourages customers to consider converting their resistive
electric space and water heating equipment to natural gas.This program is offered to residential
customers in the Idaho service territory. Customers must use Avista electricity for electric straight-
resistance heating or water heating in order to qualify for the rebate,which is verified by evaluating
their energy use.The home's electric baseboard or furnace heat consumption must indicate at least
8,000 kWh during the previous heating season. Customers receive incentives after installation and after
submitting a completed rebate form.Table 3-10 summarizes the measures offered under this program.
Table 3-10: Fuel Efficiency Program Measures
MethodologyImpact Analysis
Description
E Electric To Natural Gas Furnace Electric baseboard or forced air furnace heat Avista TRM
to natural gas forced air furnace
E Electric To Natural Gas Furnace& Electric to natural gas furnace and water heat Avista TRM
Water Heat combo
The following table summarizes the verified electric energy savings for the Fuel Efficiency Program
impact evaluation.
Table 3-11: Fuel Efficiency Program Verified Electric Savings
11 Verified
Measure 024 Expected Adjusted Verified Realization
Participation Savings Savings Savings Rate
E Electric To Natural Gas Furnace 11 66,456.00 81,224.00 73,840.00 111.11%
E Electric To Natural Gas Furnace& 4 39,156.00 39,156.00 29,367.00 75.00%
Water Heat _
Total 15 105,612.00 120,380.00 103,207.00 97.72%
The Fuel Efficiency Program displayed verified savings of 103,207.00 kWh with a realization rate of
97.72%against the expected savings for the program.The following table summarizes the incentive
costs associated with the program.
Table 3-12:Fuel Efficiency Program Incentive Costs by Measure
Measure Incentive Costs
E Electric To Natural Gas Furnace $18,900.00
E Electric To Natural Gas Furnace&Water Heat $11,400.00
Total $30,300.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Fuel Efficiency Program in the section below.
3.2.2.1 Database Review& Verification
This section describes the Evaluator's database review and document verification findings for the Fuel
Efficiency Program.
Before conducting the impact analysis,the Evaluators conducted a database review for the Fuel
Efficiency Program.The Evaluators selected a random subset of rebate applications to cross-verify
tracking data inputs, summarized in Section 2.2.2.3.
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Avista Idaho PY2024
The Evaluators found all Fuel Efficiency Program rebates to have project documentation with the
associated HVAC model number and efficiency values in either the CC&B web rebate data or mail-in
rebate applications. All the project files contained associated AHRI certifications for the installed
equipment.
Two of the AHRI AFUE values reported did not meet the criteria to qualify for calculated savings.
Therefore, savings were removed for these projects and led to a reduction in savings for the overall
measures. The individual measures and program overall displayed 97.72% realization rate.
3.2.2.2 Verification Surveys
In PY2023,the Evaluators randomly selected a subset of participant customers to survey for simple
verification of installed measure, as described in Section 2.2.2.4.The Evaluators included questions such
as:
■ Is your home heating with electricity, natural gas, or another fuel?
■ Was the previous equipment functional?
■ Is the newly installed equipment still properly functioning?
The responses to this verification survey in 2023 were used to calculate ISRs for the measures offered in
the Appliances Program in 2023 and were subsequently used to quantify ISRs in 2024.The responses to
these additional questions can be found in Appendix B.
Table 3-13 displays the ISRs for each of the Fuel Efficiency measures for the Idaho electric territory
alone, completed in PY2023.The ISRs resulted in 33.95% precision at the 90% confidence interval for the
program.
Table 3-13:Fuel Efficiency Verification Survey ISR Results
Number of Number of Precision at In-Service
Measure Rebates Survey 90% Rate
Completes Confidence
E Electric To Natural Gas Furnace 21 2 100%
E Electric To Natural Gas Furnace&Water Heat 7 3 — 90±33.95% 100%
Although the Evaluators contacted all participants for this program, response rates did not meet the
90/10 precision goal for the program.Therefore,the Evaluators assumed 100% in-service rate for this
measure. However, of the participants who did respond, all survey respondents for each furnace water
heater combination measure described equipment to be currently functioning, supporting the 100% in-
service rate assumption for this measure.
3.2.2.3 Impact Analysis
This section summarizes the verified savings results for the Fuel Efficiency Program. The Evaluators
attempted to conduct a billing analysis for the Fuel Efficiency Program measures, but participation was
insufficient to complete verified savings using this methodology. The Evaluators calculated verified
savings for the gas measures using the active Avista TRM values.These UES values were applied to a
random sample of participants, with verification of project documents such as rebate applications to
verify installation, quantity, and efficiency of the equipment.
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Avista Idaho PY2024
The following sections summarize the results of the billing analysis and the desk review, with a summary
of the verified savings for the Fuel Efficiency Program.
3.2.2.4 Billing Analysis
The Evaluators did not conduct a billing analysis for the measures in the Fuel Efficiency Program, as
there were insufficient participants.
3.2.2.5 Verified Savings
The Fuel Efficiency Program in total displays a realization rate of 97.72%with 103,207.00 kWh verified
electric energy savings in the Idaho service territory, as displayed in Table 3-11.The Evaluators reviewed
the Avista TRM values along with verified tracking data to estimate net program adjusted savings for
measures. In addition,the Evaluators reviewed and applied the current Avista TRM values for the
electric measures along with verified tracking data to estimate net program verified savings for this
measure.
The realization rate for the electric savings in the Fuel Efficiency Program deviates from 100%due to
two of the AHRI AFUE values reported not meeting the criteria to qualify for calculated savings.The
applied Avista TRM prescriptive savings value and the verified savings aligned in the tracking data,
however,the removal of savings from these two projects caused the realization rate to drop from 100%
down to 97.72%.
The Evaluators noted that the required information was validated by Avista employees prior to
confirming the rebate and that the ex-ante claimed kWh and Therms savings values aligned with those
outlined in the Avista TRM.The Evaluators recommend updating the Avista tracking database to capture
previous heating types for conversion measures, requiring home previous heating type, existing cooling
type, and home type as inputs on the rebate application forms, performing a review of the AHRI AFUE
reported values to make sure the equipment qualifies for savings, and lastly to enforce required
documents for all rebates, such as the AHRI documentation and/or full model number to verify measure
efficiency.
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Avista Idaho PY2024
3.2.3 ENERGY STAR° Homes Program
The ENERGY STAR' Homes Program provides rebates for manufactured homes within Avista's service
territory that attain an ENERGY STAR' certification.This program incentivizes ENERGY STAR' Eco-rated
homes.Table 3-14 summarizes the measures offered under this program.
Table 3-14: ENERGYSTAR®Homes Program Measures
MethodologyMeasure Description Impact Analysis
E ENERGY STAR Home-Manufactured, ENERGY STAR-rated manufactured RTF UES
Electric Only home with electric furnace
G ENERGY STAR Home- ENERGY STAR-rated manufactured RTF UES
Manufactured,Gas Only home with natural gas heating
E ENERGY STAR Home-Manufactured, ENERGY STAR-rated manufactured RTF UES
Gas&Electric home with gas and electric
The following table summarizes the verified electric energy savings for the ENERGY STAR® Homes
Program impact evaluation.
Table 3-15:ENERGYSTAR°Homes Program Verified Electric Savings
IF PY2024 Expected Adjusted Verified Verified
Measure Participati Savings Savings Savings Realization
on (kWh) (kWh) (kWh) Rate
E Energy Star Home-Manufactured, Electric 106.75%
Only
22 72,930.00 72,930.00 77,853.75
E Energy Star Home- Manufactured, Gas& o
Electric 4 12,088.00 12,088.00 97.33 0.81/0
Total 26 85,018.00 85,018.00 77,951.08 91.69%
The ENERGY STAR° Homes Program displayed verified savings of 77,951.08 kWh with a realization rate
of 91.69% against the expected savings for the program. The following table summarizes the incentive
costs associated with the program.
Table 3-16: ENERGYSTAR°Homes Program Incentive Costs by Measure
Measure
E Energy Star Home-Manufactured, Electric Only $22,000.00
E Energy Star Home-Manufactured,Gas&Electric $4,000.00
Total $26,000.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the ENERGY STAR' Homes Program in the section below.
3.2.3.1 Database Review& Verification
This section describes the Evaluator's database review and document verification findings for the
ENERGY STAR° Homes Program.
Before conducting the impact analysis,the Evaluators conducted a database review for the ENERGY
STAR° Homes Program.The Evaluators selected a random subset of rebate applications to cross-verify
tracking data inputs, summarized in Section 2.2.2.3.
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Avista Idaho PY2024
The Evaluators found no duplicate rebates in the project data and therefore did not remove any rebates
from verified savings.The Evaluators found all Energy Star Home Program rebates to have project
documentation with the associated NEEM Certification.
The Evaluators found all three "Gas& Electric" manufactured homes have gas space and water heating.
While the homes certainly seem to have electric components (e.g., an ES qualified dishwasher), gas is
the primary fuel suggesting"Gas Only" might be the more appropriate assignment.
3.2.3.2 Verification Surveys
The Evaluators did not conduct verification surveys for the ENERGY STAR° Homes Program.
3.2.3.3 Impact Analysis
This section summarizes the verified savings results for the ENERGY STAR° Homes Program.The
Evaluators calculated verified savings for the electric measures using the RTF workbook in place at the
time the savings goal for the program was finalized.These RTF UES values were applied to a random
sample of participants, with verification of project documents such as rebate applications to verify
installation, quantity, and efficiency of the equipment.
3.2.3.4 Verified Savings
The Evaluators reviewed the Avista TRM values along with verified tracking data to estimate adjusted
program savings for each of the ENERGY STAR' Homes measures. In addition,the Evaluators reviewed
and applied the current RTF UES values for each measure along with verified tracking data to estimate
net program savings.
The ENERGY STAR° Homes Program in total displays a realization rate of 91.69%with 77,951.08 kWh
verified electric energy savings in the Idaho service territory, as displayed in Table 3-15.The realization
rate for the electric savings in the ENERGY STAR' Homes Program deviate from 100% due to the
categorical differences between the applied Avista TRM prescriptive savings value and the more detailed
RTF UES categories.
The realization for the E ENERGY STAR' Home—Manufactured, Electric Only measure is lower than
100% because the expected savings that were claimed do not take heating zones and cooling zones into
account; the RTF measure-level savings take weather zones into account.The Evaluators assigned
electric savings from the RTF associated with the appropriate heating and cooling zones rather than
defaulting to an average value across both zones.The Evaluators recommend updating Avista measure
savings to reflect heating zone-specific RTF measure savings rather than averaging savings from heating
zones together.
The realization for the E ENERGY STAR' Home—Manufactured, Gas & Electric measure is low because
the expected savings employed an additive methodology between a gas-heated home and an electric-
heated home for the electric savings. However, the Evaluators reviewed the RTF and determined
manufactured home electric savings for a fully natural gas heated home would be closer to the savings
for a gas heated home with electricity.The Evaluators verified that all dual fuel homes were heated
primarily with natural gas.Therefore,the Evaluators assigned electric savings from the RTF associated
with a fully natural gas-heated home using the appropriate heating zone, which yielded a 1%electric
realization rate for this measure (and a 158% realization rate for gas savings).
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Avista Idaho PY2024
3.2.4 Appliances Program
The Appliances Program is a residential prescriptive program that offers incentives for customers to
upgrade their existing clothes washers and dryers to ENERGY STAR-rated clothes dryers and washers. In
addition, customers can receive a rebate for purchasing efficient refrigerators, freezers, and smart
thermostats.These measures can either be installed in single-family residences or in multifamily homes,
a distinction which is highlighted below in Table 3-18.
This section summarizes the impact results of the evaluation results for the Appliances Program. Table
3-17 summarizes the measures offered under this program.
Table 3-17.Appliances Program Measures
DescriptionMeasure .. . .
E Energy Star Certified Refrigerator and ENERGY STAR-certified refrigerator or RTF UES
Refrigerator-Freeze refrigerator-freezer for residential homes
E Energy Star Certified Upright Freezer ENERGY STAR-certified standard or compact RTF UES
freezer for residential homes
E Energy Star Rated Clothes Dryer ENERGY STAR-certified clothes dryer for RTF UES
residential homes
E Energy Star Rated Front Load Washer ENERGY STAR-certified clothes washer for RTF UES
residential homes
E Energy Star Rated Top Load Washer ENERGY STAR-certified clothes washer for RTF UES
residential homes
E Smart Thermostat DIY with Electric ENERGY STAR-certified Smart Thermostat with RTF UES
Heat DIY install for residential homes
E Smart Thermostat Paid Install with ENERGY STAR-certified Smart Thermostat with RTF UES
Electric Heat Paid Install for residential homes
E Line Voltage Smart Thermostat Electric Connected thermostat for multifamily homes RTF UES
Baseboard with electric heat and Electric Baseboard
The following table summarizes the verified electric energy savings for the Appliances Program impact
evaluation.
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Avista Idaho PY2024
Table 3-18:Appliances Program Verified Electric Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
E Energy Star Certified Refrigerator 239 29,512.00 29,512.00 2,759.99 9.35%
and Refrigerator-Freeze
E Energy Star Certified Upright 23 1,206.00 1,206.00 613.79 50.89%
Freezer
E Energy Star Rated Clothes Dryer 134 38,383.00 38,383.00 38,339.01 99.89%
E Energy Star Rated Front Load 86 9,840.00 9,840.00 9,839.09 99.99%
Washer
E Energy Star Rated Top Load 16 416.00 0.00 0.00 0.00%
Washer
E Smart Thermostat DIY with
24 19,474.00 13,910.00 10,244.33 52.61%
Electric Heat
E Smart Thermostat Paid Install 53 41,944.00 41,944.00 30,557.50 72.85%
with Electric Heat
E Multifamily Energy Star Certified
Refrigerator and Refrigerator- 13 1,612.00 1,612.00 91.75 5.69%
Freeze
E Multifamily Energy Star Certified 0 0.00 0.00 0.00 NA
Upright Freezer
E Multifamily Energy Star Rated 2 580.00 580.00 561.20 96.76%
Clothes Dryer
E Multifamily Energy Star Rated 5 600.00 600.00 599.94 99.99%
Front Load Washer
E Multifamily Energy Star Rated 0 0.00 0.00 0.00 NA
Top Load Washer
E Multifamily Smart Thermostat
3 1,950.00 1,950.00 1,246.53 63.92%
DIY with Electric Heat
E Multifamily Smart Thermostat 7 4,550.00 0.00 0.00 0%
Paid Install with Electric Heat
E Multifamily Line Voltage 1 76.00 76.00 71.30 93.82%
Thermostat Electric Baseboard
Total 606 150,143.00 139,613.00 94,924.43 63.22%
The Appliances Program displayed verified savings of 94,924.44 kWh with a realization rate of 63.22%
against the expected savings for the program.The following table summarizes the incentive costs
associated with the program.
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Avista Idaho PY2024
Table 3-19:Appliances Program Incentive Costs by Measure
Measure Incentive Costs
E Energy Star Certified Refrigerator and Refrigerator-Freeze $23,800.00
E Energy Star Certified Upright Freezer $900.00
E Energy Star Rated Clothes Dryer $6,550.00
E Energy Star Rated Front Load Washer $4,100.00
E Energy Star Rated Top Load Washer $800.00
E Smart Thermostat DIY with Electric Heat $3,137.94
E Smart Thermostat Paid Install with Electric Heat $8,356.68
E Multifamily Energy Star Certified Refrigerator and Refrigerator-Freeze $1,300.00
E Multifamily Energy Star Certified Upright Freezer $0.00
E Multifamily Energy Star Rated Clothes Dryer $100.00
E Multifamily Energy Star Rated Front Load Washer $250.00
E Multifamily Energy Star Rated Top Load Washer $0.00
E Multifamily Smart Thermostat DIY with Electric Heat $361.03
E Multifamily Smart Thermostat Paid Install with Electric Heat $1,050.00
E Multifamily Line Voltage Thermostat Electric Baseboard $20.00
Total $50,725.65
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for Appliances Program in the section below.
3.2.4.1 Database Review& Verification
This section describes the Evaluator's database review and document verification findings for the
Appliances Program.
Before conducting the impact analysis,the Evaluators conducted a database review for the Appliances
Program.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Section 2.2.2.3.
The rebate application form sufficiently collects all required RTF measure specification details. All rebate
applications and tracking data contain AHRI documentation or model numbers to verify model
specifications.The Evaluators were able to verify the models for RTF specifications for most projects.
The Evaluators found that only three of the sampled refrigerator/freezer measures were ESME-rated.
Although most models met ENERGY STAR Requirements, the expected savings values applied to each
refrigerator/freezer was the ESME-rated UES defined by the RTF, which is significantly higher than
ENERGY STAR-qualified products.This led to a low realization rate for these measure categories.
The Evaluators verified each model specification with values provided by ENERGY STAR qualified product
lists. The Evaluators found that two smart thermostat measures did not qualify based on Energy Star
requirements.
The Evaluators found no duplicate rebates in the project data and therefore did not remove any rebates
from verified savings.
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Avista Idaho PY2024
3.2.4.2 Verification Surveys
In PY2023,the Evaluators randomly selected a subset of participant customers to survey for simple
verification of installed measure described in Section 2.2.2.4.The Evaluators included questions such as:
■ What type of clothes washer/dryer did this equipment replace?
■ Is your home heating's water heated with electricity or natural gas?
■ Was the previous equipment functional?
Is the newly installed equipment still properly functioning?
The responses to this verification survey in 2023 were used to calculate ISRs for the measures offered in
the Appliances Program in 2023 and were subsequently used to quantify ISRs in 2024.The responses to
these additional questions can be found in Appendix B.
Table 3-20 displays the ISRs for each of the Appliances Program measures for Idaho electric territory
alone, completed in PY2023.The ISRs resulted in ±6.95% precision at the 90% confidence interval for the
program.
Table 3-20:Appliances Program Verification Survey ISR Results
Number Number of Precision In-
Measure of Survey at 90% Service
Rebates Completes Confidence Rate
E Energy Star Certified Refrigerator and Refrigerator-Freeze 230 41 97%
E Energy Star Certified Upright Freezer 35 12 100%
E Energy Star Rated Clothes Dryer 149 30 90% 99%
±6.95%
E Energy Star Rated Front Load Washer 101 17 100%
E Energy Star Rated Top Load Washer 40 8 100%
The Evaluators applied the ISRs listed in Table 3-20 to each rebate to quantify verified savings for each
measure.
3.2.4.3 Impact Analysis
This section summarizes the verified savings results for the Appliances Program.The Evaluators
calculated verified savings for the electric measures using the RTF workbook in place at the time the
savings goal for the program was finalized.
3.2.4.4 Verified Savings
The Evaluators reviewed the Avista TRM values along with verified tracking data to estimate net
adjusted program savings for those measures. Final verified savings were estimated using the RTF UES
values associated with each measure.The Appliances Program displayed 63.22% realization with
94,924.43 kWh saved, as displayed in Table 3-18.
The program verified savings resulted in a realization rate of less than 100% largely due to low savings
attributed to E Energy Star Certified Refrigerator and Refrigerator-Freeze and E Energy Star Certified
Upright Freezer projects. All fridge-freezer projects were verified to be ENERGY STAR-qualified, but not
ENERGY STAR Most Efficient (ESME).The low realization rate for the fridge-freezer measure is due to the
difference in RTF savings value between ENERGY STAR fridge-freezers (about 45kWh/year) and ESME
fridge-freezers (about 124 kWh). Avista TRM references the Standard Size Refrigerator and Refrigerator-
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Avista Idaho PY2024
Freezer-Side-mounted Freezer- ESME at 124 kWh/year savings, but the Evaluators found that no
rebated fridges met this requirement, and therefore lower RTF savings were applied.
Similarly,for the upright freezer measure, all projects were verified to be ENERGY STAR-qualified, but
not ESME-qualified.The low realization rate is due to the difference in Avista TRM and RTF savings
values.The RTF assigns ENERGY STAR freezers 18 kWh/unit, while ESME freezers are assigned 67
kWh/unit.The Avista TRM references the Standard Size Freezer- Upright—ESME savings at 67
kWh/year savings. However, because the Evaluators found that no freezers met the ESME qualifications,
the lower ENERGY STAR savings values were applied to each project.
The Evaluators attributed 0 kWh/unit savings to the E Energy Star Rated Top Load Washer because the
referenced RTF clothes washer workbook estimates that savings for this measure are negative and
therefore there are no proven RTF savings for this measure.
Lastly, one sampled thermostat model was found to not qualify based on RTF Connected Thermostat
minimum requirements.The Evaluators assigned 0 kWh savings for this project,therefore providing a
downward adjustment on verified savings.The expected savings for a Smart Thermostat measure was
defined as 749 kWh in the Avista TRM, which is in line with the RTF savings for a Smart Thermostat using
an electric Air Source Heat Pump with direct install and resistance optimization in heating zone 2;
however,the expected savings were also applied to projects verified to have electric forced-air furnace,
which the RTF UES assigns lower savings (195.36 kWh per Smart Thermostat).Therefore, a portion of
the smart thermostat verified savings were lower than the expected savings claimed for the measure.
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Avista Idaho PY2024
3.2.5 Midstream Program (Residential)
Avista converted several residential and nonresidential measures from a downstream delivery channel
to a midstream delivery channel via local distributors.As Avista notes, midstream approaches have
proven successful in other parts of the Pacific Northwest, as well as nationally.
The Midstream Program currently offers midstream incentives to residential customers for measures
such as:
■ Residential heat pump water heaters (retrofit& new construction)
■ Residential split unitary equipment(retrofit& new construction)
■ Residential mini split systems (retrofit& new construction)
The nonresidential midstream measures and impact evaluation results are presented in Section 5.3.7.
This change in delivery channel is seen to expand the benefits gained from the consumer with respect to
the midstream incentive design rather than the downstream incentive design, as well as how customers
use this offering.
This section summarizes the estimated savings Avista has calculated for the Midstream Program.The
Evaluators conducted the first impact evaluation for the measures in this program for PY2024.Table
3-21 summarizes the measures offered under this program.
Table 3-21:Midstream Program Measures
ImpactMeasure Description
Methodology
E Heat Pump Water Heater(New High efficiency heat pump water heater
Construction) installation (new construction)
E Heat Pump Water Heater(Retrofit) High efficiency heat pump water heater
installation (retrofit)
E Mini Split(New Construction) Conversion to Mini Split system installation Engineering Algorithm
(new construction) with RTF Current
E Mini Split(Retrofit) Conversion to Mini Split system installation Practice Baseline
(retrofit) Adjustments
E Split Unitary Equipment(New Conversion to Air Source Heat Pump
Construction) installation (new construction)
E Split Unitary Equipment(Retrofit) Conversion to Air Source Heat Pump
installation (retrofit)
The following table summarizes the estimated electric energy savings for the Midstream Program
impact evaluation.
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Avista Idaho PY2024
Table 3-22:Midstream Program Verified Electric Savings
PY2024
Measure Units Savings Savings Rate
E Heat Pump Water Heater(New Construction) 2 3,151 I 3,151 100.00%
E Heat Pump Water Heater(Retrofit) 2 3,212 I 3,212 100.00%
E Mini Split(New Construction) 198 169,405 299,589 176.85%
E Mini Split(Retrofit) 273 578,130 698,453 120.81%
E Split Unitary(New Construction) 20 1 36,499 36,600 100.28%
E Split Unitary(Retrofit) 402 702,083 850,163 121.09%
Total 897 1,492,479 1 1,891,167 126.71%
The Midstream Program displayed estimated savings of 1,891,167 kWh with a realization rate of
126.71%.The following table summarizes the incentive costs associated with the program.
Table 3-23:Midstream Program Costs by Measure
E Heat Pump Water Heater(New Construction) $400.00
E Heat Pump Water Heater(Retrofit) $1,300.00
E Mini Split(New Construction) $65,850.00
E Mini Split(Retrofit) $158,250.00
E Split Unitary(New Construction) _ $10,100.00
E Split Unitary(Retrofit) $164,100.00
Total $400,000.00
The Evaluators describe the impact evaluation tasks completed for this program in the subsections
below.
3.2.5.1 Database Review& Verification
This section describes the Evaluator's database review and document verification findings for the
Midstream Program.
Before conducting the impact analysis,the Evaluators conducted a database review for the Midstream
Pilot. The Evaluators selected a subset of rebates to cross-verify tracking data inputs, summarized in in
Section 2.2.2.3.
The Evaluators found all documents contained the information necessary to accurately characterize
savings for the program within the Idaho electric service territory.The Evaluators verified the model
number, efficiency, quantity, and RTF UES values necessary to calculate verified savings.The Midstream
tracking data is tracked and delivered separately from the remaining residential portfolio, often
demonstrating extensive detail on product characteristics.
3.2.5.2 Verification Surveys
The Evaluators did not conduct verification surveys for the Midstream Program in PY2024 due to the
nature of the midstream delivery channel; customers are not aware that they are participating in the
program because they are not required to fill out a downstream rebate application.
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Avista Idaho PY2024
3.2.5.3 Impact Analysis
This section summarizes the verified savings results for the Midstream Program.The Evaluators
attempted to conduct a billing analysis for each measure with sufficient participation. For measures in
which billing analysis was not feasible or displayed inconclusive results, the Evaluators evaluated verified
savings for the measure through the Regional Technical Forum workbooks in place at the time of the
biennium plan for the Midstream Program.
The Evaluators note that the expected savings workbook values from the implementer vary slightly from
the RTF UES for each of the measures. For this reason, it is expected that the realization rate will portray
discrepancies between the expected and verified savings.
The Evaluators estimated verified savings using RTF UES workbooks in the RTF's residential sector.
3.2.5.4 Billing Analysis
The Evaluators did not conduct a billing analysis for the electric measures in the Midstream Program
because of limited participation for each measure due to mid-year implementation of the program.
3.2.5.5 Verified Savings
The Evaluators reviewed the implementer expected savings values along with verified tracking data to
estimate net adjusted program savings for those measures. In order to calculate verified savings, the
Evaluators utilized industry-standard engineering algorithms using purchased equipment efficiency
values and RTF-defined market practice baseline values, where appropriate. The Midstream Program
displayed 126.71% realization with 1,891,167 kWh saved, as displayed in Table 3-22.
The Evaluators concluded that the implementers correctly estimated expected savings values for a
portion of the projects and incorrectly defined above market practice efficiency baseline for a portion of
projects.The Evaluators recommend incorporating appropriate baselines for each project, reflecting the
RTF market practice baseline present in the year in which the project was installed.
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Avista Idaho PY2024
3.2.6 On Bill Repayment Program
The On-Bill Repayment/Financing Program provides on-bill repayment/financing programs for
residential and small business customers.Avista's on-bill repayment (OBR)/financing program returned
as an offering after a half decade hiatus. In 2023 Avista started offering customers access to OBR
through its partner the Puget Sound Cooperative Credit Union (PSCCU). OBR,through PSCCU, offers
lower rate loans for energy-efficient projects to homeowners and business owners that can be more
easily tracked and paid back through their monthly utility bill. OBR is not intended for customers who
qualify for Avista's Low-Income Weatherization program and that can therefore be served directly
through the partnering community action agencies.
Avista does not claim energy savings for OBR, as the savings associated with any measure installed using
OBR financial support is claimed through the relevant and native Avista program. However, Avista
intends to claim additional educational and behavioral impacts through the OBR Program.
During the PY2024 impact evaluation,the Evaluators did not conduct an impact evaluation for the On
Bill Repayment Program.The Evaluators intend to conduct an impact evaluation of this program in
PY2025, as it is a "low risk" program. However,the Evaluators summarize the estimated electric energy
savings and costs through the program in the tables below. There were no OBR participants in the Idaho
Electric service territory in PY2024.
Table 3-24:On Bill Repayment Program Claimed Electric Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
On Bill Repayment 0 NA NA NA NA
Total 0 NA NA NA NA
Avista does not quantify expected savings for the OBR Program.The following table summarizes the
incentive costs associated with the program.
Table 3-25: On Bill Repayment Program Claimed Costs by Measure
Measure Incentive Costs
On Bill Repayment $0.00
Total $0.00
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Avista Idaho PY2024
3.2.7 Home Energy Audit Program
The Residential Home Energy Audit Program is designed to educate and generate interest in efficiency in
general and, more specifically, in Avista's portfolio of residential energy efficiency and renewable-energy
programs.The Evaluators completed a billing analysis of the census of participants to identify the
educational impact of the program on customers' energy usage behaviors while removing savings
claimed and verified from other program participation.The following table summarizes the verified
electric energy savings for the Home Energy Audit Program impact evaluation.
Table 3-26:Home Energy Audit Program Verified Electric Savings
PY2024 Expected Adjusted-7 Verified Verified
Measure Participation Savings Savings Savings Realizatiork
(kWh) (kWh) (kWh) Rate
Home
Total Energy Audit 120 NANA NA 9,418.03-]__ NA
418.03 NA
The Home Energy Audit Program displayed verified savings of 9,418.03 kWh.Avista did not estimate
claimed savings for this program, and therefore the realization rate is not applicable to the program.The
following table summarizes the incentive costs associated with the program.
Table 3-27:Home Energy Audit Program Costs by Measure
Incentive Costs
Home Energy Audit $0.00
Total $0.00
The Evaluators summarize the program-specific impact analysis activities, results, conclusions, and
recommendations for the Home Energy Audit Program in the section below.
3.2.7.1 Database Review& Verification
This section describes the Evaluator's database review and document verification findings for the Home
Energy Audit Program.
Before conducting the billing analysis,the Evaluators conducted a database review for the Home Energy
Audit Program.The Evaluators reviewed the list of participants of the Home Energy Audit Program in
PY2024.The Evaluators identified participating customers with electric service in the Idaho service
territory.The Evaluators found no duplicate participants in the project data and found that program
data appropriately reflected customer rate information.
3.2.7.2 Verification Surveys
The Evaluators did not conduct verification surveys for the Home Energy Audit Program in PY2024.
3.2.7.3 Impact Analysis
This section summarizes the verified savings results for the Home Energy Audit Program. ADM
conducted the following impact evaluation methodologies to estimate verified net energy savings in the
Residential Home Energy Audit Program:
■ Billing Analysis with counterfactual group (IPMVP Option C)
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Avista Idaho PY2024
This program provides direct install measures to customers.The Avista auditor may provide
recommendations for improvements that may be rebated through Avista's programs. In addition, the
Avista auditor may also provide recommendations for home improvements that Avista does not
currently incent for.Therefore, in order to capture this combination of effects,ADM conducted a billing
analysis with a counterfactual group selected via propensity score matching.The methodology used to
select the quasi-experimental counterfactual group and the methodology for linear regression billing
analysis are summarized in further detail in Section 2.2.3.2: Billing Analysis.
The measures rebated by the customer through other Avista channels were removed from the average
household billing analysis results, in order to remove double counted effects.
Due to the participation rate, the Evaluators included Washington Electric, Washington Gas, Idaho
Electric, and Idaho gas participants in the census billing analysis, which reflect statistically significant
electric impacts for the program.The Evaluators then removed double counted savings by removing
verified downstream rebate impacts from the billing analysis regression results.These resulting energy
savings values per household were applied to the census of participants, weighted to reflect the number
of customers with full year program participation.
3.2.7.4 Verified Savings
The Evaluators conducted a census billing analysis to estimate the impacts of the education efforts of
the Home Energy Audit Program.The table below provides annual savings per customer for the Home
Energy Audit Program after removing double counted savings from other downstream programs. Total
double counted program savings were estimated to be 1,200.73 kWh, or approximately 11%of
observed savings through billing analysis. After removing double counted savings from program impacts
reflected in the regression model, the total program savings were verified to be 9,418.03 kWh, or 165.23
kWh per customer per year, or 1.6%of annual electric household consumption.
Table 3-28: Double Counted Savings Removed, Home Energy Audit Program
ProgramWeighted Annual Savings Program
Treatment Treatment per Customer, Impacts Double
ModelCustomers Customers Regression Regression Counte (kWh)
L Estimate(kWh)
120 57 165.23 10,618.77 1 1,200.73 9,418.03
The Evaluators provide additional detail of the billing analysis completed for this program in Appendix A.
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Avista Idaho PY2024
41ow-Income Impact Evaluation Results
The Low-Income Program delivers energy efficiency measures to low-income residential customers in its
Idaho service territory with a partnership with five network Community Action Agencies ("Agencies")
and one tribal weatherization organization. The Agencies qualify income to prioritize and treat
households based on several characteristics. In-house or contract crews install approved program
measures. In addition,the Agencies have access to other monetary resources which allow them to
weatherize a home or install additional energy efficiency measures.
The Low-Income Program was not evaluated in PY2024, but will be in PY2025. For the purposes of this
report,the expected savings claimed by Avista are summarized in this section.
Table 4-1:Low-Income Verified Impact Savings by Program
Program (kWh)
Low-Income 64,877.67 NA NA
Total Low-Income 64,877.67 NA NA
In PY2024,Avista completed and provided incentives for low-income electric measures in Idaho and
achieved total electric energy savings of 64,877.67 kWh.
4.1 Program-Level Impact Evaluation Results
The Evaluators summarize the program-specific ex-ante expected savings as well as incentive costs in
the following section.
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Avista Idaho PY2024
4.1.1 Low-Income Program
The Low-Income Program delivers energy efficiency measures to low-income residential customers in its
Idaho service territory with a partnership with five network Community Action Agencies ("Agencies")
and one tribal weatherization organization. The Agencies qualify income to prioritize and treat
households based on several characteristics. In-house or contract crews install approved program
measures. In addition, the Agencies have access to other monetary resources which allow them to
weatherize a home or install additional energy efficiency measures.
Avista provides CAP agencies with the following approved measure list, which are reimbursed in full by
Avista. Avista also provides a rebate list of additional energy saving measures the CAP agencies are able
to utilize which are partially reimbursed.The following table summarizes the measures offered under
this program.
Table 4-2 summarizes the measures offered under this program.
Table 4-2:Low-Income Program Measures
Measure _ Impact Analysis Methodology
E Air Infiltration
E Air Source Heat Pump
E Attic Insulation With Electric Heat
E Conversion to Air Source Heat Pump
E Conversion to Ductless Heat Pump
E Deferred Maintenance Pilot
E Door Sweep
E Duct Insulation Avista TRM
E Duct Sealing
E Energy Star Certified Refrigerator and Refrigerator-Freeze
E Exterior Doors
E Floor Insulation With Electric Heat
E Health Safety and Repair
E Lighting
E Window Replc from Single Pane W Electric Heat
In PY2024,the Evaluators did not conduct an impact evaluation of the Low-Income Program, as it is
considered "low risk". An impact evaluation for this program is planned for PY2025. However, the
Evaluators summarize the estimated electric energy savings and costs through the program in the tables
below.
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Avista Idaho PY2024
Table 4-3:Low-Income Program Verified Electric Savings
PY2024 Expected Adjusted Verified Realizatio
Measure Participati Savings Savings Savings n Rate
E Air Infiltration 10 6,310.00 NA NA NA
E Attic Insulation With Electric Heat 3 2,526.24 NA NA NA
E Conversion to Air Source Heat Pump 7 41,057.31 NA NA NA
E Conversion to Ductless Heat Pump 1 3,016.23 NA NA NA
E Duct Insulation 2 536.00 NA NA NA
E Duct Sealing 1 709.93 NA NA NA
E Energy Star Certified Refrigerator and 1 39.00 NA NA NA
Refrigerator-Freeze
E Exterior Doors 7 1,619.40 NA NA NA
E Floor Insulation With Electric Heat 3 3,547.44 NA NA NA
E Health Safety and Repair 11 0.00 NA NA NA
E Lighting 10 62.00 NA NA NA
E Window Replc from Single Pane W Electric 8 5,454.12 NA NA NA
Heat
Total 64 64,877.67 NA NA NA
The Low-Income Program displayed estimated savings of 64,878 kWh.The following table summarizes
the incentive costs associated with the program.
Table 4-4:Low-Income Program Incentive Costs by Measure
Measure Incentive Costs
E Air Infiltration $20,369.25
E Attic Insulation With Electric Heat $7,174.10
E Conversion to Air Source Heat Pump $102,197.49
E Conversion to Ductless Heat Pump $8,593.26
E Duct Insulation $937.38
E Duct Sealing $264.50
E Energy Star Certified Refrigerator and Refrigerator-Freeze $1,999.85
E Exterior Doors $9,726.89
E Floor Insulation With Electric Heat $7,143.97
E Health Safety and Repair $23,002.59
E Lighting $279.75
E Window Replc from Single Pane W Electric Heat $32,010.95
Total $213,699.98
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Avista Idaho PY2024
5. Non-Residential Impact Evaluation Results
The Evaluators completed an impact evaluation on Avista's Non-Residential portfolio to verify program-
level and measure-level energy savings for PY2024.The following sections summarize findings for each
electric impact evaluation in the Non-Residential Portfolio in the Idaho service territory.The Evaluators
used data collected and reported in the tracking database, online application forms, Avista TRM, RTF,
IPMVP, supplemental sources and billing analysis of participants to evaluate savings.This approach
provided the strongest estimate of achieved savings practical for each program,given its delivery
method, magnitude of savings, number of participants, and availability of data.Table 5-1 summarizes
the Non-Residential verified impact savings by program.
Table 5-1:Non-Residential Verified Impact Savings by Program
Expected Savings Verified Savings Verified
Program (kWh) (kWh) Realization
Rate
Prescriptive Lighting 6,963,399 6,888,639 98.9%
Small Business Lighting 16,181,397 15,161,166 93.7%
H VAC 81,760 115,111 140.8%
Grocer 37,199 37,199 100.0%
Shell 16,263 16,263 100.0%
Green Motors No 2024 Participation
Midstream 179,583 172,150 95.9%
Site-Specific 5,335,550 5,185,351 97.2%
Building Operator Certification N/A 119,000 N/A
Total 28,795,151 27,694,878 96.2%
In PY2024, Avista completed and provided incentives for non-residential electric measures in Idaho and
achieved total electric energy savings of 27,694,878 kWh, leading to an overall achievement of 96.2% of
the expected savings for the non-residential programs.
5.1 Database & Document Verification
Before conducting the impact analyses,the Evaluators conducted a database review for all prescriptive
programs.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Document-Based Verification in Section 2.2.2.3.
The Evaluators requested rebate documentation for a subset of participating customers. These
documents included invoices, rebate applications, pictures, AHRI certificates and DLC screenshots and
similar types of documents for the following programs:
Lighting
HVAC (VFD) Program
Grocer Program
Shell Program
Midstream Program
Site-Specific Program
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Avista Idaho PY2024
This sample of documents was used to cross-verify tracking data inputs. In the case the Evaluators found
any deviations between the tracking data and application values,the Evaluators reported and
summarized those differences in the appropriate report chapters.
The Evaluators developed a sampling plan that achieves a sampling precision of±10% at 90%statistical
confidence—or"90/10 precision"—for document verification.
Table 5-2 displays program populations, sample sizes for document verification and resulting precision.
Table 5-2:Prescriptive Program Verification Precision
Program Population (Projects) Sampled (Projects) Precision
Prescriptive Lighting 417 324 90%±9.94%
Small Business Lighting 618 410 90%±10.85%
H VAC 2 2 90%±0.00%
Grocer 15 15 90%±0.00%
Shell 6 6 90%±0.00%
Midstream 86 86 90%±0.00%
Site-Specific 18 11 90%±8.14%
5.2 Survey and On-Site Verification
Unlike residential measures, non-residential measures typically have a 100% installation rate or a
deemed in-service rate (ISR) included in RTF and Avista TRM UES. The two exceptions to this are
Prescriptive Lighting measures and customs projects, such as those in the Site-Specific programs.
Verification for these programs was addressed in two ways:
5.2.1 Prescriptive Lighting Verification
To access Prescriptive Lighting ISRs the Evaluators conducted a survey of program participants during
PY2023. A total of 472 projects included a contact email, of which 74 were unique. Customers with a
valid email were sent the survey via an email invitation,followed a week later by a follow-up reminder
to those who had not responded.
The Evaluators asked participants if the rebated equipment is currently installed and working, in
addition to questions about HVAC configurations.The Evaluators achieved ±58.10% precision across the
Prescriptive Lighting Program in Avista's Idaho service territory, summarized in Table 5-3.
Table 5-3:Survey Verification
Population Respondents ISR Precision at 90%CI
472 2 1 100% ±58.10%
All respondents reported that their rebated equipment was currently installed and operating.
5.2.2 Site-Specific Verification
For the Site-Specific program,the Evaluators conducted four on-site visits to verify full installation and
equipment operation as described in the project scope. This is discussed further in the Site-Specific
chapter.
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Avista Idaho PY2024
Table 5-4:On-Site Verification
Program •.p On-Site
claimed savings)
Site-Specific 18 4 ±8.14%9
5.3 Program-Level Impact Evaluation Results
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Non-Residential sector in the section below.
9 Sampling precision based on sample stratified by kWh. Multiple projects occurred at several sites,necessitating only a single visit for multiple
sampled projects.
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Avista Idaho PY2024
5.3.1 Prescriptive Lighting Program
The Prescriptive Lighting Program is intended to prompt commercial electric customers to increase the
energy efficiency of their lighting equipment through direct financial incentives. It indirectly supports
the infrastructure and inventory necessary to ensure that the installation of high-efficiency equipment is
a viable option for customers.
In an effort to streamline the process and make it easier for customers and vendors to participate in the
program,Avista developed a prescriptive approach for commercial/industrial customers in 2004.This
program provides for many common retrofits to receive a pre-determined incentive amount.The
Prescriptive Lighting program makes it easier for customers—especially smaller customers and vendors
—to participate in the program.
The measures included in the Prescriptive Lighting program include retrofits from fluorescent lamps and
fixtures, HID, directional, and incandescent can fixtures to more energy-efficient LED light sources and
controls.
In PY2024,the Prescriptive Lighting Program accounted for the second largest share of non-residential
expected savings, or roughly 24.2%of the expected non-residential portfolio from this program alone.
Table 5-5 summarizes the measures offered under this program.
Table S-S:Prescriptive Lighting Program Measures
Location
Source
LED tubes
LED U-Bend
LED W reduction
LED Down lamps/Directional
Interior Prescriptive
Linear LED Fixtures
Calculations
HID LED fixtures/lamps
with RTF
Occupancy Sensors Inputs
LLLC Fixtures
Exterior HID LED fixtures/lamps
Sign Lighting
New Construction HID LED fixtures
Prescriptive Lighting Program impact evaluation results by measure including verified savings and
realization rates are summarized in Table 5-6.
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Avista Idaho PY2024
Table 5-6: Interior Prescriptive Lighting Program Verified Electric Savings
Measure Participation Savings Savings Savings on Rate
(Measures) (kWh) (kWh) (kWh)
>=150W Incandescent to<=30W LED 55 21,336 21,336 21,336 100.0%
Fixture
>=42W CFL to<=20W LED Fixture 167 18,963 18,963 18,963 100.0%
1000 watt HID Fixture to 400 watt or 87 299,901 299,901 299,901 100.0%
less LED Fixture
175-watt HID Fixture to 75-watt or less 20 25,480 25,480 25,480 100.0%
LED Fixture
2,3,4-Lamp T12/T8 Fixture to LED
1,724 419,576 419,576 419,576 100.0%
Qualified 2x4 Fixture
20-50 watt MR16 to MR16 LED 2-9 72 6,270 5,643 5,643 90.0%
watt
250-watt HID Fixture to 140-watt or 73 60,336 60,336 60,336 100.0%
less LED Fixture
2-Lamp T12/T8 Fixture to LED Qualified 165 31,593 31,593 31,593 100.0%
1x4 Fixture
2-Lamp T12/T8 Fixture to LED Qualified 1,191 130,997 130,997 130,997 100.0%
2x2 Fixture
400 watt HID Fixture to 175 watt or 392 455,377 455,377 455,377 100.0%
less LED Fixture
65W Incandescent to<=10 watt LED 23 3,521 3,521 3,521 100.0%
Fixture
75-100 watt Incandescent Can to less 565 97,246 97,246 97,246 100.0%
than 20 watt LED Fixture Retrofit _
Ceiling or Fixture Occupancy sensor 221 29,446 29,446 29,446 100.0%
with built-in relays
DLC Qualified LLLC Fixture 3,563 209,034 209,033 209,033 100.0%
Four Pin Base CFL to 17 watt or less 2,177 149,166 134,250 134,250 90.0%
Plug in LED
T12/T8(2') Lamp to 1-Lamp less than 318 8,724 8,576 8,576 98.3%
13 watt T8 TLED
T12/T8(3') Lamp to 1-Lamp less than 17 789 775 775 98.3%
17 watt T8 TLED
T12/T8(4') Lamp to 1-Lamp less than
23 watt T8 TLED 35,471 1,987,949 1,954,154 1,954,154 98.3%
T12/T8 8' Fixture to 90 watt or less 8' 515 129,654 127,450 127,450 98.3%
LED fixture
T12/T8 Eight-Foot to LED 1,009 107,165 105,343 105,343 98.3%
T12/T8 U-Bend to less than 23 watt T8
62 3,796 3,732 3,732 98.3%
LED
T5 Lamp to 1-Lamp less than 18 watt 218 13,857 13,857 13,857 100.0%
T5 TLED
T5HO(4')4-Lamp to 135 watt of less
37 12,513 12,300 12,300 98.3%
LED Fixture
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Avista Idaho PY2024
T5HO (4')6-Lamp to 165 watt of less 293 123,575 121,474 121,474 98.3%
LED Fixture
T51HO Lamp to 1-Lamp less than 29 5,736 868,735 853,966 853,966 98.3%
watt T5HO TLED
TLED(4') Lamp to TLED(4') Lamp with 7,675 239,460 235,389 235,389 98.3%
5 watt or more reduction
Wall Switch Occupancy Sensor 65 6,970 6,970 6,970 100.0%
1000 watt HID Fixture to 400 watt or 41 132,997 132,997 132,997 100.0%
less LED Fixture or Retrofit(Ext)
150 watt HID Fixture to 50 watt or less 61 40,262 40,262 40,262 100.0%
LED Fixture or Retrofit(Ext)
1500 watt HID Fixture to 600 watt or 49 240,491 240,491 240,491 100.0%
less LED Fixture or Retrofit(Ext)
175 watt HID Fixture to 100 watt or 219 150,333 150,333 150,333 100.0%
less LED Fixture or Retrofit(Ext)
200 watt HID Fixture to 140 watt or 2 1,030 1,030 1,030 100.0%
less LED Fixture or Retrofit(Ext)
250 watt HID Fixture to 140 watt or 143 142,384 142,384 142,384 100.0%
less LED Fixture or Retrofit(Ext)
320 and 400 watt HID Fixture to 160 or 72 66,262 66,262 66,262 100.0%
less watt LED Fixture(Ext, NC)
400 watt HID Fixture to 175 watt or 268 365,088 365,088 365,088 100.0%
less LED Fixture or Retrofit(Ext)
70-89 watt HID Fixture to 25 watt or 68 22,173 22,173 22,173 100.0%
less LED Fixture or Retrofit(Ext)
750 watt HID Fixture to 300 watt or 1 3,564 3,564 3,564 100.0%
less LED Fixture or Retrofit(Ext)
90-100 watt HID Fixture to 30 watt or 127 57,208 57,208 57,208 100.0%
less LED Fixture or Retrofit(Ext)
DLC Qualified LLLC Exterior Fixture 47 14,004 14,004 14,004 100.0%
Sign Lighting 5,771 266,172 266,157 266,157 100.0%
Total 1 68,780 6,963,399 6,888,639 6,888,639
The following table summarizes the incentive costs associated with the program.
Table 5-7:Prescriptive Lighting Program Incentives
easure
>=150W Incandescent to<=30W LED Fixture 55 $4,675
>=42W CFL to<=20W LED Fixture 167 $3,340
1000 watt HID Fixture to 400 watt or less LED Fixture 87 $51,786
175-watt HID Fixture to 75-watt or less LED Fixture 20 $3,000
2,3,4-Lamp T12/T8 Fixture to LED Qualified 2x4 Fixture 1,724 $129,300
20-50 watt MR16 to MR16 LED 2-9 watt 72 $585
250-watt HID Fixture to 140-watt or less LED Fixture 73 $19,960
2-Lamp T12/T8 Fixture to LED Qualified 1x4 Fixture 165 $6,600
2-Lamp T12/T8 Fixture to LED Qualified 2x2 Fixture 1,191 $47,562
400 watt HID Fixture to 175 watt or less LED Fixture 392 $125,542
65W Incandescent to<=10 watt LED Fixture 23 $1,265
75-100 watt Incandescent Can to less than 20 watt LED Fixture Retrofit 565 $33,530
Ceiling or Fixture Occupancy sensor with built-in relays 221 $16,575
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Avista Idaho PY2024
Measure Measure Total Electric Incentives
Count
DLC Qualified LLLC Fixture 3,563 $533,608
Four Pin Base CFL to 17 watt or less Plug in LED 2,177 $38,862
T12/T8(2') Lamp to 1-Lamp less than 13 watt T8 TLED 318 $2,862
T12/T8(3') Lamp to 1-Lamp less than 17 watt T8 TLED 17 $187
T12/T8(4') Lamp to 1-Lamp less than 23 watt T8 TLED 35,471 $489,544
T12/T8 8' Fixture to 90 watt or less 8' LED fixture 515 $46,340
T12/T8 Eight-Foot to LED 1,009 $27,131
T12/T8 U-Bend to less than 23 watt T8 LED 62 $930
T5 Lamp to 1-Lamp less than 18 watt T5 TLED 218 $3,659
T5HO(4')4-Lamp to 135 watt of less LED Fixture 37 $4,440
T5HO(4')6-Lamp to 165 watt of less LED Fixture 293 $61,530
T5HO Lamp to 1-Lamp less than 29 watt T5HO TLED 5,736 $198,819
TLED(4') Lamp to TLED(4') Lamp with 5 watt or more reduction 7,675 $53,725
Wall Switch Occupancy Sensor 65 $1,105
1000 watt HID Fixture to 400 watt or less LED Fixture or Retrofit(Ext) 41 $35,209
150 watt HID Fixture to 50 watt or less LED Fixture or Retrofit(Ext) 61 $10,980
1500 watt HID Fixture to 600 watt or less LED Fixture or Retrofit(Ext) 49 $63,200
175 watt HID Fixture to 100 watt or less LED Fixture or Retrofit(Ext) 219 $38,616
200 watt HID Fixture to 140 watt or less LED Fixture or Retrofit(Ext) 2 $240
250 watt HID Fixture to 140 watt or less LED Fixture or Retrofit(Ext) 143 $30,298
320 and 400 watt HID Fixture to 160 or less watt LED Fixture(Ext, NC) 72 $18,000
400 watt HID Fixture to 175 watt or less LED Fixture or Retrofit(Ext) 268 $96,601
70-89 watt HID Fixture to 25 watt or less LED Fixture or Retrofit(Ext) 68 $5,570
750 watt HID Fixture to 300 watt or less LED Fixture or Retrofit(Ext) 1 $80
90-100 watt HID Fixture to 30 watt or less LED Fixture or Retrofit(Ext) 127 $13,748
DLC Qualified LLLC Exterior Fixture 47 $3,995
Sign Lighting 5,771 $74,811
Total 68,780 $2,297,808
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Prescriptive Lighting Program in the section below.
5.3.1.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Prescriptive
Lighting Program. The Evaluators review all rebate applications to cross-verify tracking data inputs,
summarized in Section 5.1. Data points checked between project applications and program tracking
counts, wattages/DLCs sheets, hours of operation and measure cost values. Below,Table 5-8 shows the
project population, the number of projects checked and the overall precision.
Table 5-8:Prescriptive Lighting Program Verification Precision
Population(Projects)
417 324 ±9.94%
Below, Table 5-9 shows the count of discrepancies found between program tracking and project-level
data.
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Avista Idaho PY2024
Table 5-9:Prescriptive Lighting Program Verification Findings
Count Correction Location . .n Hours CorrectionCorrection
0 1 0 1 0 1 3
Three line items had baseline and efficient wattages reversed. No other corrections were made.
5.3.1.2 Impact Analysis
The Evaluators calculated verified savings by using a standard engineering algorithm:
kWh N x Wfixt(i)l — XWfixt(i)]post)
x AOH x ISR
savings — [ fixt(i) 1000 J [Nf ixt(i) 1000 pre
Where:
■ Nfixt(i), pre = Pre-retrofit number of fixtures of type i
■ Nfixt(i), post= Post-retrofit number of fixtures of type i
■ Wfixt(i), pre= Rated wattage of pre-retrofit fixtures of type i (Standard Wattage Table developed
from RTF materials)
■ Wfixt(i), post= Rated wattage of post-retrofit fixtures of type i (Varies). Self-reported.
■ AOH =Annual operating hours for specified space type (Varies). Self-reported.
■ ISR =The In-Service Rate, based on type. RTF estimates. See Table 5-10 below.
Table 5-10:Lighting In-Service Rates
Type ISR
Screw-in 96.4%
Linear 98.3%
Pin-based 90.0%
Fixture _ 100.0%
The Evaluators completed surveys with 5 program participants and asked participants if the rebated
equipment was installed and operating. The RTF does not provide storage rate estimates for integral
fixtures however survey responses for this measure are statistically significant and show a 100% ISR.
5.3.1.3 Verified Savings
The verified savings for the program is 6,888,639 kWh with a realization rate of 98.9%, as displayed in
Table 5-6. Two factors affected the overall realization rate: The Evaluators used the RTF Midstream
Lighting work books and assigned ISRs according to the rates shown above in Table 5-10, resulting in
slightly lower verified savings than expected.
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Avista Idaho PY2024
5.3.2 Small Business Lighting
New in 2024,the Small Business Lighting Program is a non-residential direct install lighting program
implemented by Resource Innovations. The program offers lighting and controls assessments,
equipment and installation for commercial customers on rate schedules 11 or 12.
To participate, businesses fill out a request on the Avista website and then are contacted by a program
partner. An on-site assessment is scheduled to identify potential lighting and sensor upgrades needed
and eligibility is verified. Measures are then installed at low/no cost to the participant and incentivized
at $0.40 -$0.65/kWh.
In PY2024, the Small Business Lighting Program accounted for the largest share of non-residential
expected savings, or roughly 56.2% of the expected non-residential portfolio from this program alone.
Table 5-11 summarizes the measures offered under this program.
Table 5-11:Small Business Lighting Program Measures
Measure
LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W
LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W with OCC
LED Fixture-replacing FLT12,400W-1000W with OCC
LED Fixture-replacing FLT5:2ft to 8ft, 14W-54W with OCC
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,400W-1000W with OCC
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W-59W with OCC
LED Retrofit Kit-replacing FLT12,400W-1000W with OCC
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp, 100W-250W with OCC
LED Replacement Lamp-replacing FLT12:2ft to 8ft,34W-80W with OCC
LED Retrofit Kit-replacing FLT8:2ft to 8ft, 17W-59W with OCC
Prescriptive
LED Replacement Lamp-replacing FLT5:2ft to 8ft, 17W-54W with OCC Calculations with
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,<100W with OCC Custom Inputs
LED Fixture-replacing Halogen/Incandescent lamp,20-150W with OCC
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,320W-400W with OCC
LED Replacement Lamp-replacing Halogen/Incandescent lamp,20-150W with OCC
LED Fixture-replacing Halogen/Incandescent lamp, 150W- 1500W with OCC
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium lamp,400W-
1000W with OCC
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,400W-1000W
LED Replacement Lamp-replacing FLT5:2ft to 8ft, 17W-54W
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W-59W
LED Fixture-replacing Halogen/Incandescent lamp,20-150W
Small Business Lighting Program impact evaluation by measure and then are summarized in Table 5-12.
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Avista Idaho PY2024
Table 5-12:Small Business Lighting Program Verified Electric Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
(Measures) (kWh) (kWh) (kWh)
LED Fixture-replacing CFL Screw- o
in/Pin-based,8W-40W
15 18,468 18,456 18,456 99.9/
LED Fixture-replacing FLT12,400W- 127 356,096 357,240 357,240 100.3%
1000 W
LED Fixture-replacing FLT12,400W- 249 1,740,530 1,527,699 1,527,699 87.8%
1000W with OCC
LED Fixture-replacing FLT5: 2ft to 8ft, 23 138,158 139,963 139,963 101.3%
14W-54W
LED Fixture-replacing FLT5: 2ft to 8ft, 57 860,249 689,509 689,509 80.2%
14W-54W with OCC
LED Fixture-replacing FLT8:2ft to 8ft, 143 473,477� 476,924 476,924 100.7%
17W-59W
LED Fixture-replacing FLT8: 2ft to 8ft, 289 1,954,802 1,712,676 1,712,676 87.6%
17W-59W with OCC
LED Fixture-replacing
Halogen/Incandescent lamp, 150W- 88 352,956 352,956 352,956 100.0%
1500W
LED Fixture-replacing
Halogen/Incandescent lamp, 150W- 10 37,438 29,676 29,676 79.3%
1500W with OCC
LED Fixture-replacing
H 280 960,429 960,431 960,431 100.0%
Halogen/Incandescent lamp, 20-150W
LED Fixture-replacing
Halogen/Incandescent lamp, 20-150W 94 144,275 112,976 112,976 78.3%
with OCC
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp,< 24 26,553 26,553 26,553 100.0%
100W
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp, 177 529,523 529,531 529,531 100.0%
100W-250W
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp, 3 4,221 3,474 3,474 82.3%
100W-250W with OCC
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp, 91 517,361 517,369 517,369 100.0%
320W-400W
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp, 14 207,850 159,318 159,318 76.7%
320W-400W with OCC
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp, 41 952,379 957,214 957,214 100.5%
400W-1000W
LED Fixture-replacing Metal
Halide/High Pressure Sodium lamp, 4 83,763 65,827 65,827 78.6%
400W-1000W with OCC
LED Fixture-replacing T12:2ft-8ft, 46 183,744 183,744 183,744 100.0%
34W-80W
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Avista Idaho PY2024
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
(Measures) (kWh) (kWh) (kWh)
LED Fixture-replacing T12:2ft-8ft, 84 532,326 403,277 403,277 75.8%
34W-80W with OCC
LED Replacement Lamp-replacing CFL 4 9,842 9,842 9,842 100.0%
Screw-in/Pin-based,8W-40W
LED Replacement Lamp-replacing 81 411,626 411,635 411,635 100.0%
FLT12:2ft to 8ft,34W-80W
LED Replacement Lamp-replacing 17 76,532 77,448 77,448 101.2%
FLT12: 2ft to 8ft,34W-80W with OCC
LED Replacement Lamp-replacing 13 65,654 65,654 65,654 100.0%
FLT5: 2ft to 8ft, 17W-54W
LED Replacement Lamp-replacing 1 5,669 7,997 7,997 141.1%
FLT5: 2ft to 8ft, 17W-54W with OCC
LED Replacement Lamp-replacing 154 1,161,423 1,161,458 1,161,458 100.0%
FLT8: 2ft to 8ft, 17W-59W _
LED Replacement Lamp-replacing 11 51,499 51,132 51,132 99.3%
FLT8: 2ft to 8ft, 17W-59W with OCC
LED Replacement Lamp-replacing
Halogen/Incandescent lamp, 150- 7 47,981 47,981 47,981 100.0%
1500 W
LED Replacement Lamp-replacing 265 1,733,325 1,733,341 1,733,341 100.0/
Halogen/Incandescent lamp,20-150W
LED Replacement Lamp-replacing
Halogen/Incandescent lamp, 20-150W 14 58,824 55,521 55,521 94.4%
with OCC
LED Replacement Lamp-replacing
Metal Halide/High Pressure Sodium 2 1,752 1,752 1,752 100.0%
lamp,<100W
LED Replacement Lamp-replacing
Metal Halide/High Pressure Sodium 7 36,608 36,608 36,608 100.0%
lamp, 100W-250W
LED Replacement Lamp-replacing
Metal Halide/High Pressure Sodium 2 15,089 15,089 15,089 100.0%
lamp,320W-400W
LED Retrofit Kit-replacing CFL, 8W- 2 375 375 375 100.0%
40W
LED Retrofit Kit-replacing FLT12, 17 118,316 118,318 118,318 100.0%
400W-1000W
LED Retrofit Kit-replacing FLT12,400W-1000W with OCC 45 329,394 286,984 286,984 87.1%
LED Retrofit Kit-replacing FLT12: 2ft
4 78,745 78,745 78,745 100.0%
to 8ft,34W-80W
LED Retrofit Kit-replacing FLT12:2ft 6 113,711 86,145 86,145 75.8%
to 8ft,34W-80W with OCC
LED Retrofit Kit-replacing FLT5: 2ft to
1 403 403 403 100.0%
8ft, 14W-54W
LED Retrofit Kit-replacing FLT5:2ft to 9 208,666 161,584 161,584 77.4%
8ft, 14W-54W with OCC
LED Retrofit Kit-replacing FLT8:2ft to 35 263,128 269,447 269,447 102.4%
8ft, 17W-59W
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PY2024 Expected Adjusted Verified Realization
easure Participation Savings Savings Savings Rate
(Measures) (kWh) (kWh) (kWh)
LED Retrofit Kit-replacing FLT8:2ft to 62 625,342 569,031 569,031 91.0%
8ft, 17W-59W with OCC
LED Retrofit Kit-replacing 42 147,495 147,495 147,495 100.0%
Halogen/Incandescent lamp,20-150W
LED Retrofit Kit-replacing
Halogen/Incandescent lamp,20-150W 73 496,724 496,748 496,748 100.0/
LED Retrofit Kit-replacing
Halogen/Incandescent lamp, 20-150W 1 3,101 2,349 2,349 75.8%
with OCC
LED Retrofit Kit-replacing
Halogen/Incandescent lamp, 20-150W 2 9,703 7,398 7,398 76.2%
with OCC
LED Retrofit Kit-replacing Metal
Halide/High Pressure Sodium lamp,< 3 14,188 14,188 14,188 100.0%
100 W
LED Retrofit Kit-replacing Metal
Halide/High Pressure Sodium lamp, 8 21,685 21,685 21,685 100.0%
100W-250W
Total 2,747 16,181,397 15,161,166 15,161,166 93.7%
The following table summarizes the incentive costs associated with the program.
Table 5-13:Small Business Lighting Program Costs by Measure
Measure Measure Count Total Electric
(Savings Units) Incentives
LED Fixture-replacing CFL Screw-in/Pin-based,8W-40W 314 $11,997
LED Fixture-replacing FLT12,400W-1000W 3,355 $230,142
LED Fixture-replacing FLT12,400W-1000W with OCC 10,355 $1,221,357
LED Fixture-replacing FLT5:2ft to 8ft, 14W-54W 1,428 $79,302
LED Fixture-replacing FLT5:2ft to 8ft, 14W-54W with OCC 5,142 $603,445
LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W 6,454 $307,227
LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W with OCC 19,353 $1,469,500
LED Fixture-replacing Halogen/Incandescent lamp, 150W-1500W 314 $222,690
LED Fixture-replacing Halogen/Incandescent lamp, 150W-1500W with 42 $26,015
OCC
LED Fixture-replacing Halogen/Incandescent lamp,20-150W 2,461 $585,360
LED Fixture-replacing Halogen/Incandescent lamp,20-150W with OCC 554 $106,879
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,<100W 93 $16,812
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp, 100W- 697 $334,118
250 W
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp, 100W- 8 $2,894
250W with OCC
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp, 320W- 388 $332,745
400W
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,320W- 176 $143,951
400W with OCC
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LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,400W- 414 $597,568
1000 W
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,400W- 23 $55,596
1000W with OCC
LED Fixture-replacing T12: 2ft-8ft,34W-80W 1,448 $118,163
LED Fixture-replacing T12:2ft-8ft,34W-80W with OCC 2,800 $389,982
LED Replacement Lamp-replacing CFL Screw-in/Pin-based,8W-40W 128 $3,440
LED Replacement Lamp-replacing FLT12:2ft to 8ft,34W-80W 2,714 $163,743
LED Replacement Lamp-replacing FLT12:2ft to 8ft,34W-80W with OCC 559 $33,647
LED Replacement Lamp-replacing FLT5:2ft to 8ft, 17W-54W 782 $26,261
LED Replacement Lamp-replacing FLT5:2ft to 8ft, 17W-54W with OCC 64 $3,548
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W-59W 11,850 $462,040
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W-59W with OCC 559 $21,757
LED Replacement Lamp-replacing Halogen/Incandescent lamp, 150- 63 $17,883
1500 W
LED Replacement Lamp-replacing Halogen/Incandescent lamp,20-150W 4,763 $667,211
LED Replacement Lamp-replacing Halogen/Incandescent lamp,20-150W 309 $23,919
with OCC
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium 8 $701
lamp,<100W
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium 48 $14,643
lamp, 100W-250W
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium 13 $6,035
lamp,320W-400W
LED Retrofit Kit-replacing CFL,8W-40W 13 $171
LED Retrofit Kit-replacing FLT12,400W-1000W 1,012 $53,237
LED Retrofit Kit-replacing FLT12,400W-1000W with OCC 2,033 $161,790
LED Retrofit Kit-replacing FLT12:2ft to 8ft,34W-80W 940 $35,435
LED Retrofit Kit-replacing FLT12:2ft to 8ft,34W-80W with OCC 1,020 $66,825
LED Retrofit Kit-replacing FLT5:2ft to 8ft, 14W-54W 4 $181
LED Retrofit Kit-replacing FLT5:2ft to 8ft, 14W-54W with OCC 1,060 $103,395
LED Retrofit Kit-replacing FLT8:2ft to 8ft, 17W-59W 3,199 $118,404
LED Retrofit Kit-replacing FLT8:2ft to 8ft, 17W-59W with OCC 6,708 $344,538
LED Retrofit Kit-replacing Halogen/Incandescent lamp,20-150W 344 $68,240
LED Retrofit Kit-replacing Halogen/Incandescent lamp,20-150W 1,337 $223,274
LED Retrofit Kit-replacing Halogen/Incandescent lamp,20-150W with 6 $900
OCC
LED Retrofit Kit-replacing Halogen/Incandescent lamp, 20-150W with 35 $4,501
OCC
LED Retrofit Kit-replacing Metal Halide/High Pressure Sodium lamp,< 40 $6,384
100W
LED Retrofit Kit-replacing Metal Halide/High Pressure Sodium lamp, 59 $9,758
100W-250W
Total 95,489 $9,497,604
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Small Business Lighting Program in the section below.
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5.3.2.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Small
Business Lighting Program.The Evaluators reviewed a representative sample (410) of projects,verifying
that wattages listed in program tracking data were those specified by product literature. For measures
listed as having integrated occupancy sensors,this configuration was also checked. No discrepancies
were found. Below,Table 5-14 shows the project population,the number of projects checked and the
overall precision.
Table 5-14:Small Business Lighting Program Verification Precision
Population . 0 Precision
-
608 410 ± 10.85%
Table 5-15:Prescriptive Lighting Program Verification Findings
Count Correction Location Correction . Correction . .
0 0 0 0
A total of 251 sampled projects did not include sufficient information to complete a verification of all
measures: many lighting models used simple 7-digit codes as identifiers, making verification impossible.
All other line items in the project were verified. Since the same lighting models appeared in many
projects,verification could be extrapolated to non-sampled projects, resulting in a much higher
verification percentage than the reported minimum 10.85%.
5.3.2.2 Impact Analysis
The Evaluators calculated verified savings by using a standard engineering algorithms:
5.3.2.3 Lighting Fixtures
kWh g — ([Nfixt(i) x Wfixt(i)]pre
- rNxWfixt(i)]post)
x AOH x ISR
savin s — 1000 Lfixt(i) 1000
Where:
■ Nfixt(i), pre = Pre-retrofit number of fixtures of type i
■ Nfixt(i), post= Post-retrofit number of fixtures of type i
■ Wfixt(i), pre= Rated wattage of pre-retrofit fixtures of type i (Standard Wattage Table developed
from RTF materials)
■ Wfixt(i), post= Rated wattage of post-retrofit fixtures of type i (Varies). Self-reported,verified.
■ AOH =Annual operating hours for specified space type (Varies). Self-reported.
■ ISR =The In-Service Rate. Due to the DI delivery channel,this is assumed to be 100%.
5.3.2.4 Occupancy Sensors
kWh — i x Wfixt(i)lx AOH x reduction
savings — [Nf xt(i) 1000 ]post
Where:
■ Nfixt(i), post= Post-retrofit number of fixtures of type i
■ Wfixt(i), post= Rated wattage of post-retrofit fixtures of type i (Varies). Self-reported,verified.
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■ AOH =Annual operating hours for specified space type (Varies). Self-reported.
■ reduction =The reduction in operating hours as a result of the installation of occupancy sensors,
32%for fixture/ceiling mounted sensors.
5.3.2.5 Verified Savings
The verified savings for the program are 15,161,166 kWh with a realization rate of 93.7%, as displayed in
Table 5-12. For measures without occupancy sensors, realization is ±1%of expectations, with any
differences likely due to rounding. For measures with occupancy sensor,the Evaluators found that
expected savings were calculated by applying the occupancy sensor reduction factor both the operating
hours and the connected load of the lighting retrofit, slightly'double counting' savings. To account for
occupancy sensor savings in verified calculations,the Evaluators applied the 32% reduction to the
operation of the post-install equipment,then added this value to the retrofit savings, resulting in slightly
lower verified savings.
5.3.2.6 Recommendations for Future Program Cycles
■ Collect information for both lighting make and model. Current documentation only captures
lighting model and many line items only provide a 7-digit model number,which is not sufficient
to perform verification of these items.
■ Report savings from lighting retrofits and sensor installation separately.
■ Specify the type of control method employed.
■ In tracking data, denote the wattage controlled by each installed occupancy sensor.
■ If possible, record building type,vintage and HVAC configuration to calculate and include
additional savings resulting from HVAC interactive effects.
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5.3.3 Prescriptive HVAC VFD Program
The Prescriptive HVAC Variable Frequency Drive Program is intended to prompt customers to increase
the energy efficiency of their HVAC fan or pump applications with a Variable Frequency Drive (VFD)
retrofit. Adding a VFD to HVAC systems is an effective tool for cutting operating costs, improving overall
system performance, and reducing wear and tear on motors.The prescriptive rebate approach issues
payment to the customer after the measure has been installed. Commercial customers who use Avista
electricity and apply the VFD to an eligible fan or pump measures are eligible for this program.
The Prescriptive HVAC Variable Frequency Drive Retrofit Program is offered for retrofitting VFDs on
existing HVAC equipment. Customers must submit a completed rebate form, invoices, and
documentation to verify the horsepower of the motor on which the VFD was installed within 90 days of
installation.This program is promoted by trade allies,Avista account executives,the Avista website, and
Avista marketing efforts.The website is also used to communicate program requirements, incentives,
and forms.
Table 5-16 summarizes the measures offered under this program.
Table 5-16: Prescriptive HVAC VFD Program Measures
MethodologyMeasure Impact Analysis
HVAC Cooling Pump Avista TRM UES
HVAC Fan Avista TRM UES
HVAC Heating Pump or Combo Avista TRM UES
The following table summarizes the verified electric energy savings for the Prescriptive HVAC VFD
Program impact evaluation.
Table 5-17.Prescriptive HVAC VFD Program Verified Electric Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation savings savings savings Rate
VFDs on Clean Air Systems 1 51,100 73,972 73,972 144.8%
VFDs on Exhaust Systems 1 30,660 41,139 41,139 134.2%
Totals 2 81,760 115,111 115,111 140.8%
The following table summarizes the incentive costs associated with the program.
Table 5-18: Prescriptive HVAC VFD Program Incentives
TotalMeasure Count
VFDs on Clean Air Systems 1 $7,023
VFDs on Exhaust Systems 1 $5,420
Total 2 $12,443
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Prescriptive HVAC VFD Program in the section below.
5.3.3.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Prescriptive
HVAC VFD Program.The Evaluators review all rebate applications to cross-verify tracking data inputs,
summarized in Section 5.1. Verification of project documents included data points such as quantity,
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motor horsepower, installation location and costs of the equipment. Table 5-19 shows the project
population, the number of projects checked and the overall precision.
Table 5-19:Prescriptive HVAC VFD Program Verification Precision
Sampled .
2 2 ±0
The Evaluators did not find any deviations between project applications and program tracking data.
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Prescriptive HVAC VFD Program.
5.3.3.2 Impact Analysis
This section summarizes the verified savings results for the Prescriptive HVAC VFD Program.The
Evaluators calculated verified savings for VFD measures using the RTF VSD 3.0. Specific application and
horsepower were taken into account when selecting verified savings estimates. RTF deemed savings
estimates are larger than those assumed in Avista tracking data, resulting
5.3.3.3 Verified Savings
The Evaluators reviewed and applied the current RTF UES values to verified tracking data to estimate net
program savings for this measure.The verified savings for the program is 115,111 kWh with a realization
rate of 140.8%, as displayed in Table 5-17.
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5.3.4 Grocer Program
This program offers incentives to customers who increase the energy efficiency of their refrigerated
cases and related grocery equipment. Refrigeration often represents the primary electricity expense in a
grocery store or supermarket. The prescriptive rebate approach issues payment to the customer after
the measure has been installed. Commercial customers who use Avista fuel for the measure applied for
are eligible.
Customers must submit a completed rebate form and invoice within 90 days after the installation has
been completed.This program is promoted by trade allies, Avista account executives,the Avista
website, and Avista marketing efforts.The website is also used to communicate program requirements,
incentives, and forms.
Table 5-20 summarizes the measures offered under this program.
Table 5-20: Grocer Program Measures
MethodologyImpact Analysis
Refrigerator Case Lighting RTF EUS
ASH Controls RTF EUS
Door Gaskets Avista TRM UES
Floating Head Pressure Controls RTF EUS
Strip Curtains RTF EUS
Walk-In ECM Controllers RTF EUS
ECMs on Evaporator Fans Avista TRM UES
ECM Replacing Evaporator PS and PSC RTF EUS
Refrigerator Case Lighting RTF Commercial Grocery Display Case Lighting v1.2
ASH Controls RTF EUS
Door Gaskets RTF EUS
Floating Head Pressure Controls RTF EUS
Strip Curtains RTF EUS
The following table summarizes the verified electric energy savings for the Grocer Program impact
evaluation.
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Table 5-21:Grocer Program Verified Electric Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
(Projects) (kWh) (kWh) (kWh)
1/20HP_ECM replacing o
1/20HP_Shaded Pole 2 3,016 3,016 3,016 100.0/
20W_ECM replacing
20W_Shaded Pole 2 2,057 2,057 2,057 100.0%
Walk-In Cooler Evaporator
Fan Motor- 1/15 HP Shaded 4 10,656 10,656 10,656 100.0%
Pole to 1/15 HP ECM
Walk-In Freezer Evaporator
Fan Motor- 1/15 HP Shaded 1 5,310 5,310 5,310 100.0%
Pole to 1/15 HP ECM
Evaporator Fan ECM Motor
Controller-Walk-In-Low 2 608 608 608 100.0%
Temp->44 Watt-1 or 2
motors/controller
Evaporator Fan ECM Motor
Controller-Walk-In- 2 1,376 1,376 1,376 100.0%
Medium Temp->44 Watt- 1
or 2 motors/controller
Medium Temp_ECM
replacing Shaded Pole_10 to 5 7,126 7,126 7,126 100.0%
15 W output power
Low Temp_ECM replacing
Shaded Pole_10 to 15 W 4 7,050 7,050 7,050 100.0%
output power
Total 22 37,199 37,199 37,199 100.0%
The following table summarizes the incentive costs associated with the program.
Table 5-22:Grocer Program Incentives
Measure Measure Count Total Electric Incentives
ECMs on Evaporator Fans 4 $200
ECM Replacing Evaporator PS and PSC 54 $4,200
Totals: 58 $4,400
The Evaluators summarize the program-specific and measure-specific impact analysis activities and
results for the Grocer Program in the section below.
5.3.4.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Grocer
Program.The Evaluators review all rebate applications to cross-verify tracking data inputs, summarized
in Section 5.1. Data points checked between project applications and program tracking including
measure specification, quantity and measure cost values.
Table 5-23 shows the project population, the number of projects checked and the overall precision.
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Table 5-23: Verification Precision
Population . - .
Precision
15 15 ±0%
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Grocer Program.
5.3.4.2 Impact Analysis
This section summarizes the verified savings results for the Prescriptive Food Service Equipment
Program.The Evaluators calculated verified savings for the food service measures using RTF UES in place
at the time the savings goals for the program were finalized. Final verified savings were calculated by
applying the appropriate UES to a census of measures.
5.3.4.3 Verified Savings
The Evaluators reviewed and applied the appropriate UES values to verified tracking data to estimate
program savings for these measures.The verified savings for the program is 37,199 kWh with a
realization rate of 100.0%, as displayed in Table 5-21.
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5.3.5 Prescriptive Shell Program
The Commercial Prescriptive Shell Program offers incentives to commercial customers who improve the
envelopes of their existing buildings by adding insulation, which may make a business more energy-
efficient and comfortable.This prescriptive rebate approach issues payment to the customer after the
measure has been installed by a licensed contractor. Commercial customers must have an annual
heating footprint for a fuel provided by Avista.
Customers must submit a completed rebate form, invoices, and an insulation certificate within 90 days
after the installation has been completed.Avista will send incentive checks to customers or their
designees after each project is approved.This program is promoted by trade allies,Avista account
executives, the Avista website, and Avista marketing efforts.The website is also used to communicate
program requirements, incentives, and forms.
Table 5-24 summarizes the measures offered under this program.
Table 5-24:Prescriptive Shell Program Measures
ImpactMeasure ... .
Attic Insulation Avista TRM UES
Roof Insulation Avista TRM UES
Wall Insulation Avista TRM UES
The following table summarizes the verified electric energy savings for the Prescriptive Shell Program
impact evaluation.
Table 5-25:Prescriptive Shell Program Verified Electric Savings
PY2024 Expected Adjusted Verified
Measure Participation Savings Savings Savings Realization
(Projects) (kWh) (kWh) (kWh) Rate
Attic=<R11 to R30-R44 1 492 492 492 100.0%
Attic=< R11 to R45+ 4 8,884 8,884 8,884 100.0%
Wall =< R4 to 19+ 2 6,887 6,887 6,887 100.0%
Totals 7 16,263 16,263 16,263 100.0%
The following table summarizes the incentive costs associated with the program.
Table 5-26:Shell Program Incentives
Measure Measure Count(Square Feet Total Electric Incentives
Attic=<R11 to R30-R44 529 $529
Attic=< R11 to R45+ 16,196 $7,171
Wall=<R4 to 19+ 1,691 $2,114
Total 18,416 $9,814
The Evaluators summarize the program-specific and measure-specific impact analysis activities and
results for the Prescriptive Shell Program in the section below.
5.3.5.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Prescriptive
Shell Program.The Evaluators review all rebate applications to cross-verify tracking data inputs,
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summarized in Section 5.1. Data points checked between project applications and program tracking
include R-levels, square footage of installation, HVAC configuration and measure cost values. Below,
Table 5-27 shows the project population, the number of projects checked and the overall precision.
Table 5-27: Prescriptive Shell Program Verification Precision
7 7 ±0%
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Prescriptive Shell Program.
5.3.5.2 Impact Analysis
This section summarizes the verified savings results for the Prescriptive Shell Program.The Evaluators
calculated verified savings for the insulation measures using the 2022 Avista TRM, in place at the time
the savings goals for the program were finalized. Final verified savings were calculated by applying the
appropriate UES to a census of measures.
5.3.5.3 Verified Savings
The Evaluators reviewed and applied the current TRM UES values for the Attic and Wall Insulation
measures along with verified tracking data to estimate net program savings for this measure.The
verified savings for the program is 16,263 kWh with a realization rate of 100.0%, as displayed Table 5-25.
During the evaluation,the Evaluators noticed that building fuel types did not include indicators as to
whether gas heated facilities used electric air conditioners. Both facility heating and cooling equipment
information should be included in tracking data.
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5.3.6 Green Motors Program
The Green Motors Program ensures quality rewinding that results in the motor maintaining its original
efficiency,which is commonly called a "green rewind."The Green Motors Practices Group (GMPG) is a
non-profit organization that identifies, promotes, and verifies only excellent member motor service
centers.These companies are committed to consistently producing repair/rewinds that retain or
improve reliability and efficiency and provide on-site motor driven systems assistance.
The incentive for this program is$1 per HP of the motor being rewound, up to $10,000 for 5,000 HP, and
is taken directly off the customer bill at the service center.There is also a $1 per HP fee paid to the
service center for participating.
Table 5-28 summarizes the measures offered under this program.
Table 5-28: Green Motors Program Measures
MethodologyMeasure Impact Analysis
Motor Rewind (Industrial) Avista TRM 2024 UES
In PY2024 there were no participation or claimed kWh savings from the Green Motors Program.
Table 5-29:Green Motors Program Electric Savings
PY2024 Expected A.
Measure Participation Savings Savings Savings Rate Total 0 0 0 0 N/A
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5.3.7 Midstream Program (Non-Residential)
Avista designed the Midstream Program to shift the onus of applying for rebates from end-use
customers to distributors. Not only does this reduce customers'/contractors' administrative burden (i.e.,
no need to submit paperwork tracking energy efficient installations), but it is also anticipated to increase
high-efficiency equipment options at competitive prices. Midstream rebates provide an immediate
discount on eligible products, which appear as a line item on customer invoices. Starting on July 1, 2023,
the Midstream Program replaced Avista's residential and commercial downstream space-heating and
water-heating programs as well as the commercial food service equipment rebate program.
Through the Midstream Program,Avista seeks to achieve three overall objectives:
Provide greater long-term, cost-effective savings for residential and commercial customers
alike
Reduce Avista's administrative burden in processing space-heating, water-heating, and
commercial kitchen equipment applications
Accelerate the market transformation of energy-efficient equipment
The Midstream Program provides bought-down equipment to both Residential and Commercial entities.
This chapter discusses and presents results only for the non-residential measures.
Table 5-30 summarizes the measures rebated in PY2024 under this program.
Table 5-30:Non-Residential Midstream Program Measures
MethodologyMeasure Measure Impact Analysis
Combination Oven RTF Combination Ovens
Convection Oven RTF Convection Ovens
Dishwasher Avista TRM
Food Service Fryer RTF Fryers
Griddle RTF Griddle
Hot Food Holding Cabinet RTF HFHC
Ice Machine RTF Ice Makers
HVAC Heat Pumps Engineering algorithm
Mini/Multi Split Engineering algorithm
The following table summarizes the verified electric energy savings for the Midstream Program impact
evaluation.
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Table 5-31:Non-Residential Midstream Program Verified Electric Savings
PY2024 Expected Verified Savings
Measure Participation Savings(kWh) (kWh) Realization Rate
Combination Oven 6 35,777 41,411 115.7%
Convection Oven 3 5,984 5,982 100.0%
Dishwasher 7 40,615 43,342 106.7%
Fryer 1 3,812 872 22.9%
Griddle 1 1,823 2,455 134.7%
Hot Food Holding Cabinet 1 398 398 100.0%
Ice Machine 8 3,184 3,184 100.0%
Mini/Multi Split 70 81,009 68,870 85.0%
Heat Pumps(Split/Packaged) 8 6,981 5,636 80.7%
Total 105 179,583 172,150 95.9%
The following table summarizes the incentive and non-incentive costs associated with the program.
Table 5-32:Non-Residential Midstream Incentives
Measure Measure Count Incentive Costs
Combination Oven 6 $14,100
Convection Oven 4 $4,200
Dishwasher 7 $11,640
Fryer 1 $3,600
Griddle 1 $1,850
Hot Food Holding Cabinet 1 $250
Ice Machine 12 $3,675
Mini/Multi Split 74 $42,500
Heat Pumps(Split/Packaged) 8 $3,000
Totals 114 $84,815
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Midstream Program in the section below.
5.3.7.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Midstream
Program. Due to the program delivery pathway,the Program does not include project applications. For
this program,the Evaluators examined a representative sample of projects to ensure that program
tracking data accurately reflected measure characteristics used in assessing savings. Data points checked
include: equipment configurations, capacities and efficiency levels.
Table 5-33 shows the project population, the number of projects checked and the overall precision.
Table 5-33:Non-Residential Midstream Program Verification Precision
Population Sampled Precislor
86 86 0.0%
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Midstream Program and no substantive equipment specifications differed from those in the tracking
data.
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5.3.7.2 Impact Analysis
Once verification was completed, to estimate program savings for these measures the Evaluators
reviewed and applied the appropriate UES values from the Regional Technical Forum (RTF). If a measure
was not covered by the RTF then a UEF from the Avista TRM was used as the source for verified savings,
followed by the California eTRM (CA eTRM) as a third appropriate source. Unit energy savings sourced
from the and were taken from measure package versions in place at the time of program planning.
Verified savings for food service equipment was taken from RTF and CA eTRM workbooks and is specific
to the equipment configuration(s).
Savings for Mini/Multi Splits, Package/Unitary/Split HVAC Equipment and Water Source Heat Pumps was
calculated using standard engineering algorithms,with equipment-specific inputs for capacity and
efficiency, and EFLH values from the Midstream planning workbook. Savings calculations for storage and
tankless water heaters were carried out in the same way, using actual equipment specifications and
prescriptive water use estimates for each building type, based on regional use data.
5.3.7.3 Verified Savings
The verified savings for the program were 172,150 kWh with a realization rate of 95.9%, as displayed in
Table 5-32.
■ Fryers:The source of expected savings is unclear. Verified savings were sourced from the RTF
and reflect electric savings for a 'standard vat-sized fryer.
■ Mini/Multi Splits:The Evaluators were unable to fully recreate expected savings,though for 45
new construction projects, a 7.1 was used as a baseline HSPF. While 7.1 is a weighted average
representing existing heating equipment types (ER and gas) for retrofit projects where the true
baseline is unknown. For new construction projects,the baseline s the current building/energy
code, 7.5.This alone does not fully describe all differences between expected and verified
savings, but is a systematic contributor the deviation.
■ Split and Packaged Heat Pumps:The Evaluators were unable to determine how expected
savings were calculated. Using identical methodology to program planning materials,the
Evaluators calculated 'expected' savings which would yield near 100% realization rates, but
claimed savings estimates did not correspond with any known method for determining savings.
Simply put, claimed savings were roughly half the results of using other methods.
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5.3.8 Site-Specific Program
The Site-Specific Program provides calculated incentives to support the installation of qualifying energy
efficiency equipment at commercial/industrial sites.These projects typically have a higher degree of
complexity than the traditional prescriptive offerings and rely on custom calculations of savings and
incentive levels. Examples of these projects include process improvements, upgrades to specialized
equipment used in manufacturing, lighting installations that rely on specialized controls, and other
measures designed around the customer's specific needs.
Avista's Site-Specific Program is a major component in its non-residential electric offerings.The program
approach strives for a flexible response to energy efficiency projects that have demonstrable kWh
savings within program criteria.The majority of site-specific kWh savings are composed of custom
lighting projects and custom HVAC, envelope, and industrial process load projects that do not fit the
prescriptive path.The Site-Specific Program is available to all commercial/industrial retail electric
customers, and typically brings in the largest portion of savings to the overall energy efficiency portfolio.
In PY2024,the Site-Specific Program accounted for the second largest share of non-residential expected
savings, or roughly 18.5%of the expected non-residential portfolio from this program alone.
The following table summarizes the verified electric energy savings for the Site-Specific Program impact
evaluation.
Table 5-34:Site-Specific Program Verified Electric Savings
ParticipationRealization
18 1 5,335,550 5,185,350 1 97.2
The Site-Specific Program displayed verified savings of 5,185,350 kWh with a realization rate of 97.2%
against the expected savings for the program. Below,Table 5-36 breaks savings into Lighting and Non-
Lighting:
Table 5-35:Site-Specific Program Lighting and Non-Lighting Savings
Savings Source Expected Savings(kWh) 1 Verified Savings(kWh) ' Verified Realization Rate
Lighting 327,812 291,696 89.0%
Non-Lighting 5,007,737 4,893,654 97.7%
Total 5,335,550 5,185,350 97.2%
Table 5-36:Site-Specific Program Incentives
Type Count of Projects Incentives
Lighting 7 $76,878
Non-Lighting 11 $1,085,599
Total 18 $1,162,476
The Evaluators summarize the program-specific and measure-specific impact analysis activities and
results for the Site-Specific Program in the section below.
5.3.8.1 Sample Design
Unlike other non-residential programs, completing a census review of all Site-Specific projects is not
feasible. To ensure accurate verified savings estimates, the Evaluators developed a sample of
representative sites to inspect using the Stratified Random Sampling procedure detailed in 2.2.2.2.This
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procedure provides 90%confidence and +/- 10% precision with a significantly reduced sample than
random sampling would require, by selecting the highest saving facilities with certainty,thereby
minimizing the variance that non-sampled sites can contribute to the overall results.
The participant population for the Site-Specific Program was divided into five strata. Table 5-37
summarizes the strata boundaries and sample frames for the Site-Specific Program.
Table 5-37:Site-Specific Program Sample Design
Descriptor Stratum 1 Stratum 2 Stratum3 Stratum 4 Stratum 5 Totals
Strata
10,001- 50,001- 300,001-
boundaries <10,000 50,000 300,000 1,000,000 >1,000,001
(kWh)
Number of 2 6 6 2 2 18
projects
Total kWh 10,181 146,679 826,572 1,209,772 3,142,346 5,335,550
savings
Average kWh 5,091 24,447 137,762 604,886 1,571,173 296,419
Savings
Standard
deviation of 2,312 13,667 75,579 28,512 604,617 525,934
kWh savings
Coefficient of 0.454 0.559 0.549 0.529 0.385 1.774
variation
Final design 2 3 2 2 2 11
sample
The highest-savings was specifically selected for verification and analysis. Verified sampling precision is
±8.20%at 90%.
Table 5-38:Site-Specific Program Sample Summary
#Sites in Population Review Sample Size Precision
18 11 8.14%at 90%
5.3.8.2 Project Document Review and On-Site Visits
Once representative projects were selected,the Evaluators obtained all project-related documentation
for review. These documents typically included spec sheets, building characteristics, calculators,
invoices, project photos and trending data. This information allowed the Evaluators to replicate claimed
savings estimates and develop M&V plans to be used in assessing verified savings and collecting on-site
data.
Using project-specific M&V plans,the Evaluators visited sampled sites to verify measure installation and
operating parameters, as well as building parameters such as square footage and HVAC configurations.
The Evaluators conducted site visits at 4 of the 11 sampled sites,with two projects occurring at the same
site.
5.3.8.3 Impact Approaches
Eighteen (18) projects were lighting projects and could be analyze using standard savings algorithms.
Below, the two equations show the algorithms used in calculating savings from lighting projects.
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kWh — ([Nfixt(i) x Wfixt(i)]pre
_ [NXWfixt(i)]post)
x AOH x IEF
savings — 1000 Lfixt(i) 1000
kW - J C[N x Wfixt(i)1 _ [N X Wfixt(i)]post)
X CF x IEF
savings — \ fixt(i) 1000 J fixt(i) 1000 pre
Where:
■ Nfixt(i), pre = Pre-retrofit number of fixtures of type i
■ Nfixt(i), post= Post-retrofit number of fixtures of type i
■ Wfixt(i), pre= Rated wattage of pre-retrofit fixtures of type i (Standard Wattage Table developed
from RTF materials)
■ Wfixt(i), post= Rated wattage of post-retrofit fixtures of type i (Taken from project spec sheets)
■ CF = Peak demand coincidence factor(80%,for most measures)
■ AOH =Annual operating hours for specified space type (Varies. Collected during M&V site visits)
■ IEF = Site-Specific Interactive effects factor specific to building and Site-Specific configuration
(developed from RTF materials)
For non-lighting projects, specific methodology varies between IPMVP Options A-C, and is described in
the sections below.
5.3.8.4 Site-Level Realization
Adjusted and verified savings were developed for each sample site.The realization rates for sites within
each stratum were then applied to the non-sampled sites within their respective stratum.Table 5-39
presents realization at the site level,with Table 5-40 presenting results at the stratum level.
Table 5-39:Site-Specific Expected,Adjusted and Verified kWh Savings by Sampled Project
Project ID FlExpected Savings(kWhF7 Verified Savings(kWh) Realization Rate
SSOP_140807 3,456 872 25.2%
SSLP_138273 6,725 6,725 100.0%
SSLP_140329 16,913 16,913 100.0%
SS LP_140390 22,941 22,941 100.0%
SSOP_140225 33,718 33,718 100.0%
SSLP_128331 99,774 59,558 59.7%
SSLP 111655 155,461 159,561 102.6%
SSOP_107281 378,651 412,391 108.9%
SSOP_143029 831,121 831,327 100.0%
SSO P_77417 1,143,644 1,143,644 100.0%
SSO P_82450 1,998,702 1,934,101 96.8%
Total 4,691,106 4,621,751 98.5%
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Table 5-40:Site-Specific Summary of kWh Savings by Sample Stratum and Overall
Stratum Expected Savings(kWh) Verified Savings(kWh) Realization Rate
1 10,181 7,598 74.6%
2 146,679 146,679 100.0%
3 826,572 709,611 85.8%
4 1,209,772 1,243,718 102.8%
5 3,142,346 3,077,745 97.9%
Total 5,335,550 5,185,351 97.2%
Table 5-41:Site-Specific Summary of kWh Savings by End Use
Savings Source Expected Savings(kWh) Verified Savings(kWh) Verified Realization Rate
Lighting 327,812 I 291,696 I 89.0%
Non-Lighting 5,007,737 4,893,655 97.7%
Total 5,335,550 5,185,351 97.2%
5.3.8.5 Discussion of Non-100%Realization
Below are brief explanations of differences between claimed and verified savings for projects with
realization rates that are not 100%.
■ SSOP_140807—Verified savings were measured with a whole-facility billing analysis. Measured
savings were lower than calculated ex-ante savings. Discrepancies in savings could not be
traced because the implementer did not provide the calculations used to develop initial savings
estimates. Low RRs suggest either that occupant behavior has changed since the
implementation of the project or that the initial analysis did not adequately capture the
relationship (or lack thereof) between energy usage and exterior temperature.
■ SSOP_140225—A whole-facility billing analysis was completed and produced statistically
significant savings, however the estimates greatly exceeded expectations (693.9%of
expectations), or indeed what can reasonably be expected in savings from the refrigeration
measures installed.This indicates the significant other changes, such as additional equipment or
changes in occupancy took place conflating results. The evaluators examined projects
documents and calculated prescriptive savings estimates based on available data. While
documentation did not provide the level of detail to fully replicate expected savings,verification
estimates were similar to and corroborated claimed savings,thus the results of this project are
considered to be 100% realization.
■ SSLP_128331—An error in project record keeping assigned savings attributable only to lighting
HVAC savings (as a result of the reduced load on the HVAC system). These misplaced savings
artificially inflated savings expectations. While no other corrections or changes were made, this
lowered the verified savings to 59.7%.
■ SSLP_111655—Expected savings for seven interior lighting line items could not be exactly
recreated, ranging between 98.5% and 104.4%of savings expectations. Using verified input
data,the Evaluators calculated savings to be 102.6%of expectations.
■ SSOP_107281—The discrepancy in savings are likely a result of minor differences in billing
analysis specification (the Evaluators used linear regression, Implementer used alternative
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method), and/or inputs: Historical weather data source (ADM used NOAA, Implementer used
alternative source), and normalization (ADM normalized usage to TMYx data, Implementer did
not perform any usage normalization). Results verified savings are 108.9%or expectations.
■ SSOP-82450—The discrepancy in motor replacement savings is likely due to the inclusion of
low-RPM data points from the raw SCADA data in the binning process. The discrepancy in
cooling blower savings is likely due to rounding. Combined,these produce 96.8%of expected
savings.
5.3.8.6 Verified Savings
The Site-Specific Program in total displays a realization rate of 97.2%with 5,185,350 kWh verified
electric energy savings in the Idaho service territory, as displayed in Table 5-40.
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5.3.9 Building Operator Certification
The C&I Building Operator Certification Program is being offered by Avista in the 2024-2025 biannual
period.This program is offered to encourage building operator certified (BOC) credentialed operators to
save electricity and natural gas in buildings they manage while reducing electrical demand.The BOC
program has consistently produced positive documented energy savings and has proved to be cost
effective.Third party evaluators have assessed and documented the BOC's energy savings impacts"
The Evaluators used the BOC independent impact evaluation completed by NEEA, approved by the
Washington Utilities and Transportation Commission to estimate verified electric impacts for the
program.
Table 5-42 summarizes the electric measures offered under this program and corresponding impact
M&V methodology source,for each building operator certification completed in PY2024.
Table 5-42:Building Operator Certification Program LIES Sources
Impact Analysis Savings Section(s)
I_ Building Operator Certification—Electric
WUTC approved BOC's energy savings impactsll
Building Operator Certification—Natural Gas
The independent study by Navigant12 indicates annual savings of roughly 119,000 kWh per operator.The
assumed measure life is five years, meaning that the methodology assigns savings for five years
beginning in the year of certification for each operator. If a student receives a Level 2 certification or a
certification renewal, then the measure life extends for five years from the most recent date of
certification.The WUTC approved BOC document stipulates "Active building operator refers to building
operators who have obtained a new certification or renewed a previous certification within the past 5
years".The Evaluators applied these third-party results to each building operator who has completed a
certification within the past 5 years. The following table summarizes the verified electric energy savings
for the BOC Program impact evaluation.
Table 5-43:BOC Program Verified Electric Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
Building Operator Certification 1 119,000 119,000 119,000 100.00%
Total 1 7119,000 119,000 119,000 100.00%
The following table summarizes the incentive and non-incentive costs associated with the program.
Table 5-44: BOC Incentives
CountMeasure Participant Total Incentive
Building Operator Certification 1 $0
Total 1 $0
10 https://www.theboc.info/wp-content/uploads/2020/08/2020-BOC-Energy-Savings-FAQ_1.O.pdf
11 https://www.theboc.info/wp-content/uploads/2020/08/2020-BOC-Energy-Savings-FAQ_1.0.pdf
12 https://www.theboc.info/pdf/Eval-Ell-223_LTMT.pdf
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The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the BOC Program in the section below.
5.3.9.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the BOC
Program.The Evaluators reviewed all incented course and non-course applications, completion dates,
and results.The Evaluators found a total of one building operator certifications were completed in 2024.
5.3.9.2 Verified Savings
The Evaluators reviewed and applied the appropriate NEEA electric impacts approved by the WUTC
estimate customer-level and program-level savings for this program.The verified savings for the
program were 119,000 kWh with a realization rate of 100.0%, as displayed in Table 5-43.
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6-Appendix A: Billing Analysis Results
This appendix provides additional details on the billing analyses conducted for each program.
6.1 Home Energy Audit Program
The results of the billing analysis for the Home Energy Audit are provided below.Table 6-1 shows
customer counts for customers considered for billing analysis (i.e. customers present in each the
Washington Electric, Washington Gas, Idaho Electric, and Idaho Gas service territories) and identifies
measures that met the requirements for a billing analysis.A billing analysis was completed for measures
that had at least 75 customers with single-measure installations.This ensured that measures would have
a sufficient sample size after applying PSM data restrictions (e.g. sufficient pre-and post-period data).
The billing analysis included participants in Washington and Idaho service territories to acquire the
maximum number of customers possible. The billing analysis on individual measures resulted in
statistically significant electric impacts.The following section reports the combined analysis.
Table 6-1:Measures Considered for Billing Analysis, Home Energy Audit Program
Isolated-MeasureMeasure Number of Sufficient
Measure onsidered for Customers w/ Participation
Billing Analysis
Installations* Analysis
Home Energy Audit ✓ 1,505* ✓
*This count includes rebates from Washington and Idaho
The Evaluators were successful in creating a matched cohort for each of the measures with sufficient
participation. Customers were matched on zip code (exact match) and their average pre-period seasonal
usage, including summer,fall, winter, and spring for each control and treatment household.The
Evaluators were provided a considerable pool of control customers to draw upon, as shown in Table 6-2.
Also shown in Table 6-2, are the impact of various restrictions on the number of treatment and control
customers that were included in the final regression model. The "Starting Count" displays the beginning
number of customers available prior to applying the data restrictions, while the "Ending Count" displays
the number of customers after applying data restrictions and final matching.
Table 6-2: Cohort Restrictions, Home Energy Audit Program
Measure Data Restriction Treatment Control
Customers Customers
Starting Count 1,505 50,000
Install Date Range:January 1,2022 to June 30,
2024 1,427 49,766
Home Energy Audit
Incomplete Post-Period Bills(<6 months)and
incomplete Pre-Period Bills(<9 months) 636 41,717
Ending Count(Matched by PSM) 633 1,198
For the combined measures, the covariate balance shows moderate differences between the treatment
and control groups before and after matching. Control usage seems to be substantially lower than
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treatment usage before matching; however, after running PSM,treatment and control groups are very
similar on aggregate.
The Evaluators performed three tests to determine the success of PSM:
1. t-test on pre-period usage by month
2. Joint chi-square test to determine if any covariates are imbalanced
3. Standardized difference test for each covariate employed in matching
All tests confirmed that PSM performed well for each measure.The t-test displayed no statistically
significant differences at the 95% level in average daily consumption between the treatment and control
groups for any month in the pre-period.
Table 6-3 provides results for the t-test on pre-period usage between the treatment and control groups
after matching for the Shell program. The P-Value is over 0.05 for each month except January, meaning
pre-period usage between treatment and control groups is similar at the 95% confidence level.
Table 6-3:Pre-period Usage T-test for Home Energy Audit Program Washington and Idaho
Average Daily Average Daily -I
Usage(kWh), Usage(kWh), T Statistic P-Value Reject Null?=
Control Treatment
Jan 38.80 36.55 2.07 1.20 0.04 Yes
Feb 35.51 33.94 1.57 1.14 0.12 No
Mar 30.35 29.54 0.96 0.99 0.34 No
Apr 24.98 24.24 0.87 0.89 0.38 No
May 21.46 21.32 0.15 0.72 0.88 No
Jun 22.69 23.05 -0.50 0.80 0.62 No
Jul 26.92 27.56 -0.66 0.99 0.51 No
Aug 25.68 25.81 -0.11 0.93 0.91 No
Sep 21.36 20.73 0.88 0.78 0.38 No
Oct 24.25 22.96 1.58 0.91 0.12 No
Nov 33.05 31.29 1.42 1.38 0.16 No
Dec 37.71 35.44 1.55 1.60 0.12 No
Table 6-4 provides customer counts for customers in the final regression model,weighted by full
program year participation. That is, if a customer received a home energy audit on July 1, 2024, the
savings applied to the customer is half of the full impact displayed from the regression analysis after
double counted savings removal.
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Table 6-4: Weighted Participants, Home Energy Audit Program
Measure #of Treatment Customers Weighted Customers
Washington Electric 271 123
Idaho Electric 120 57
Washington Gas 851 411
Idaho Gas 263 130
Total 1,505 721
The table below provides annual savings per customer for the Home Energy Audit Program for the PPR
model.The PPR model was selected for ex post savings because it provided the best fit for the data
(highest adjusted R-squared). Savings are statistically significant at the 90% level for the combined
measures but the adjusted R-squared shows the model provided a poor fit for the data.
Table 6-5:Regression Savings, Home Energy Audit Program
Annual Savings per Customer Adjusted R-Squared Model
across WA and ID census(kWh)
212.91 0.81 PPR
After extrapolating regression coefficients to ID electric customers,the Evaluators identified 10,618.77
kWh in savings across 57 weighted treatment customers for an average annual savings of 186.29 kWh.
Double counted savings were then subtracted from that per-customer total.The table below provides
annual savings per Avista ID electric customer for the Home Energy Audit Program after removing
double counted savings from other downstream programs.Total double counted program savings was
estimated to be 1,200.73 kWh, or approximately 11%of observed savings through billing analysis.After
removing double counted savings from ID electric program impacts,the total program savings were
verified to be 9,418.03 kWh, or 165.23 kWh per customer per year, or 1.6%of annual electric household
consumption.
Table 6-6:Double Counted Savings Removed, Home Energy Audit Program
ProgramWeighted Annual Savings Program
Treatment Treatment per Customer, Impacts D. ble Verified Savings
ModelCustomers Customers Regression Regression Counted (kWh)
Estimate(kWh)
120 57 165.23 10,618.77 1,200.73 9,418.03
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7.Appendix 6: Summary of Survey Respondents
This section summarizes additional insights gathered from the simple verification surveys deployed by
the Evaluators for the impact evaluation of Avista's Residential and Low-Income Programs in PY2023.
Because a simple verification survey was not completed in PY2024, the Evaluators utilized the response
results from PY2023 for the PY2024 project completion in-service rates.
Survey respondents confirmed installing between one and three measures that were rebated by Avista,
displayed in Table 7-1.This table is missing information from 29 low-income, CEEP, and MFDI survey
respondents who did not indicate the number nor type of measures they received.
Table 7-1: Type and Number of Measures Received by Respondents
Measure Category Total Percent
No Measures 304 13.8%
One Measure 1218 55.4%
Two Measures 440 20.0%
Three Measures 171 7.8%
Four Measures 47 2.1%
Five or more measures 20 0.9%
HVAC 289 13.1%
Water Heater 136 6.2%
Smart Thermostat 515 23.4%
Clothes Washer 297 13.5%
Clothes Dryer 189 8.6%
The Evaluators asked respondents to provide information regarding their home, as displayed in Table
7-2. Similar to the previous impact evaluation findings, the majority of respondents noted owning a
single-family home between 1,000 and 3,000 square feet with central air conditioning.
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Table 7-2:Survey Respondent Home Characteristics13
.. Percent
Own 93.8%
Rent 1.9%
Do you rent your home?(n=755) Own and rent to someone else 1.3%
1 don't know 0.1%
Prefer not to answer 2.9%
Single-family house detached 86.0%
Single-family house attached to 2 3%
one or more other houses
Mobile or manufactured home 8.2%
Which of the following best Apartment with 2 to 4 units 0.8%
describes your home? (n=755)
Apartment with 5+units 0.3%
Other 1.4%
1 don't know 0.2%
Prefer not to answer 0.7%
Does your home have central air Yes 72.6%
conditioning?(n=755)
Less than 1,OOOft2 6.6%
1,000-1,999ft2 42.4%
About how many square feet is 2 0
your home?(n=629) 2,000-2,999ft 32.3/
3,000-3,999ft2 13.5%
4,000ft2 or more 5.2%
Before 1950 20.0%
1950 to 1959 10.3%
1960 to 1969 6.6%
When was your home built? 1970 to 1979 15.3%
(n=719) 1980 to 1989 7.7%
1990 to 1999 15.3%
2000 to 2009 13.2%
2010 to 2019 4.7%
2020 to Present 5.6%
1 don't know 1.1%
Prefer not to answer 0.2%
13 Four contractors or construction companies were not asked these questions.
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8.Appendix C: Site-Specific M&V Reports
Project Number SSOP_113679
Project Background
The participant is a fast-food restaurant that received incentives from Avista for installing electronic
defrost controls on its cooler and freezer.
M&V Methodology
The Evaluators reviewed all project documentation including plans, photos, invoices, and simulation
outputs to verify the installation of rebated equipment. On site,the Evaluators verified this information.
The Evaluators attempted to measure savings estimates through a whole facility billing analysis,
however the results were not statistically significant.
To verify savings,the Evaluators instead examined materials used to develop expected savings
estimates, scrutinizing each of the inputs and cross-checked the model results using engineering
algorithms. The Evaluators found all assumptions and inputs to be reasonable, and prescriptive
calculations carried out to verify estimates yielded similar kWh savings estimated, corroborating savings
claims.
Results
For project#SSOP_113679,the kWh realization rate is 100%.
Verified Gross Savings& Realization Rates
r Measure Verified
�IkWh Savings kW Savings kWh Realization Rate Therm Realization Rate
BAS 1,259 N/A 100.0% N/A
Totals: 1,259 N/A 100.0% N/A
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Project Number SSLP_117017
Project Background
The participant is fast food restaurant that received incentives from Avista for retrofitting energy efficient
interior lighting.The Evaluators verified the participant had installed:
■ (33) 3L F24T51-10s were replaced by(33) Sylvania 3L 2ft T5HE LED
■ (6) 3L F24T51-10s were replaced by(6) Sylvania 3L 2ft T5HE LED
M&V Methodology
The Evaluators reviewed all project documentation including plans, calculators, photos and invoices, to
verify the installation of rebated equipment. Savings for the lighting measures were calculated using
industry standard lighting retrofit algorithms. Annual lighting hours of operation and peak coincidence
factors are based verified actual hours of lighting operation.
The values used in calculating savings are presented in the table below.
Savings Inputs
HVAC
Space Type Configuration Pre Annual Hours Post Annual Hours CF
Fast Food AC,gas heat 3,640 3,640 80%
Fast Food AC,gas heat 8,760 8,760 100%
Savings Calculations
Using deemed values from the table above,the evaluators calculated lighting savings as follows:
Lighting Retrofit kWh Savings Calculations
Quantity Wattage Pre Post Expected Adjusted Verified kWh
Measure (Fixtures) — - AOH AOH kWh kWh kWh Realization
Base Post Base Post Rate
3L F24T5HO
to Sylvania 3L 33 33 63 21 3,640 3,640 5,589 5,589 5,589 100.0%
2ft T5HE LED
3L F24T5HO
to Sylvania 3L 6 6 63 21 8,760 8,760 2,445 2,445 2,445 100.0%
2ft T5HE LED
Jotals: 8,034 8,034 8,034 100.0%
Lighting Retrofit kW Savings Calculations
Quantity(Fixt=���O Expected l Adjusted Verified kW
Measure Base kW kW kW Realization
mom Rate
3L F24T5HO
to Sylvania 3L 33 33 63 21 0.80 1.23 1.23 1.23 100.0%
2ft T5HE LED
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3L F24T5HO
to Sylvania 3L 6 6 63 21 1.00 0.22 0.22 0.28 127.3%
2ft T5HE LED
Totals: 1.45 1.45 1.51 104.1%
Results
For project#SSLP_117017 the kWh realization rate is 100.0%and the kW realization rate is 104.1%.
Verified Gross Savings, Realization Rates&Adjustments
Verified Verified kWh kWh kW Therm
Measure kWh kW Realization Realization Adjust- Adjust- Penalty
Savings Reduction Rate Rate ments ments
3L F24T5HO to
Sylvania 3L 2ft 5,589 1.23 100.0% 100.0% 0 0.00 -90
T5HE LED
3L F24T5HO to
Sylvania 3L 2ft 2,445 0.28 100.0% 127.3% 0 0.00 -40
T5HE LED
Totals: 8,034 1.51 100.0% 104.1% 0 0.00 -130
By default, expected savings are calculated using an 80% peak CF. One of the retrofitted areas' lights
operate continuously, so the peak coincidence factor for this area was changed to 100%, resulting in a
slightly higher verified peak kW reduction.
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Project Number SSLP_82210
Project Background
The participant is a restaurant that received incentives from Avista for retrofitting energy efficient interior
lighting.The Evaluators verified the participant had installed:
■ (4) 11-HPS 100s were replaced by(4)40W LED
■ (63) 11-60W Incs were replaced by(63) 9W A19 LED
■ (19) 1L 15W CFs were replaced by(19) 9W BR30 LED
M&V Methodology
The Evaluators reviewed all project documentation including plans, calculators, photos and invoices, to
verify the installation of rebated equipment.The Evaluators also conducted an onsite visit to the facility
to verify installation, assumed operating parameters and HVAC configuration(s). Savings for the lighting
measures were calculated using industry standard lighting retrofit algorithms. Annual lighting hours of
operation and peak coincidence factors are based verified actual hours of lighting operation.
The values used in calculating savings are presented in the table below.
Savings Inputs
HVAC Pre Annual Hours Post Annual Hours
Configuration
Exterior none 4,288 4,288 0%
Full Service
AC,gas heat 3,276 3,640 30%
Restaurant
Full Service
AC,gas heat 8,766 3,640 100%
Restaurant
Savings Calculations
Using deemed values from the table above,the evaluators calculated lighting savings as follows:
Lighting Retrofit kWh Savings Calculations
Quantity I kWh
(Fixtures) Wattage Pre Expected Adjusted Verified Realization
AOH kWh kWh kWh
Base—FPos­t Base Post Rate
1L HPS 100
to 40W LED 4 4 130 40 4,288 4,288 1,544 1,544 1,544 100.0%
11-60W Inc
to 9W A19 63 63 43 9 3,276 3,276 7,859 7,578 7,578 100.0%
LED
1L 15W CIF
to 9W 14 14 18 9 3,276 3,276 446 446
BR30 LED
605 144.1%
1L 15W CIF
to 9W 5 5 18 9 8,766 8,766 426 426
BR30 LED
Measurement and Evaluation Report 95

Avista Idaho PY2024
Totals: 10,008 9,994 9,994 99.9%
Lighting Retrofit kW Savings Calculations
Measure =I Wattage CIF Expected Adjusted Verified Realization
kW kW kW
I Rate
1L HPS 100 to 40W LED 4 4 130 40 0.00 0.29 0.29 0.00 0.0%
1L 60W Inc to 9W A19 LED 63 63 43 9 0.30 1.92 1.85 0.69 37.3%
1L 15W CF to 9W BR30 LED 14 14 18 9 0.30 0.04 0.04
0.15 61.3%
1L 15W CF to 9W BR30 LED 5 5 18 9 1.00 0.05 0.05
Totals: 2.35 2.29 0.78 33.2%
Results
For project#SSLP_82210 the kWh realization rate is 99.9%and the kW realization rate is 31.9%.
Verified Gross Savings, Realization Rates&Adjustments
Verified-T Verified kWh---F-kW kWh kW Therm
Measure kWh kW Realization Realization Adjust- Adjust- Penalty
Savings Reduction Rate Rate ments ments
1L HPS 100 to
40W LED 1,544 0.00 100.0% 0.0% 0 0.00 0.00
1L 60W Inc to 9W
A19 LED 7,578 0.69 100.0% 37.3% 0 0.00 -72.61
1L 15W CF to 9W
BR30 LED 446 0.04 144.1% 61.3% 446 0.04 -5.80
1L 15W CF to 9W
426 0.05 426 0.05 -4.08
BR30 LED
Totals: 9,994 0.78 99.9% 33.2% 0 0.00 -82.49
Expected savings calculations assumed 3,276 annual hours of operation for all (19) BR-30 lamps
however, during the on-site visit the Evaluators found that five of the lamps were left on continuously,
so 8,766 hours and a 100% peak CF were used in verified savings calculations, resulting in higher-than-
expected kWh savings and peak kW reduction. By default expected savings are calculated using an 80%
peak CF,though using the verified operating schedule the Evaluators calculated a 30% chance the
remaining interior lights would be operating during peak hours, and a 0%chance for exterior lamps,
resulting in a lower verified peak W reduction. Lastly, expected savings calculations for(63) LED A-lamps
assumed an erroneous HCIF interaction factor(1.12), whereas 1.08 should have been used for the entire
interior of this facility(a full service restaurant with AC and gas heating built prior to 2006).This
adjustment resulted in slightly lower verified kWh and kW estimates for these lamps.
Measurement and Evaluation Report 96

Avista Idaho PY2024
Project Number SSLP_82041
Project Background
The participant is social club with a boat storage area that received incentives from Avista for retrofitting
energy efficient interior lighting.The Evaluators verified the participant had installed:
■ (34)4L F54T51-10s were replaced by(26) 1L 148W LED
■ (41)4L F54T51-10s were replaced by(26) 1L 181W LED
M&V Methodology
The Evaluators reviewed all project documentation including plans, calculators, photos and invoices, to
verify the installation of rebated equipment.The Evaluators also conducted an onsite visit to the facility
to verify installation, assumed operating parameters and HVAC configuration(s). Savings for the lighting
measures were calculated using industry standard lighting retrofit algorithms. Annual lighting hours of
operation and peak coincidence factors are based verified actual hours of lighting operation.
The values used in calculating savings are presented in the table below.
Savings Inputs
Space Type HVAC Pre Annual Hours Post Annual Hours
Configuration I
Conditioned
Gas heat, no AC 3,640 3,640 43%
Storage
Savings Calculations
Using deemed values from the table above,the evaluators calculated lighting savings as follows:
Lighting Retrofit kWh Savings Calculations
QuantityPre •.
st Expected Adjuste Verifie kWh
4L F54T5H0 Base I Post Base Post n Rate
to 1L 148W 34 26 236 148 2,087 2,087 14,353 14,353 13,202 92.0%
LED
4L F54T5HO
to 1L 181W 41 26 236 182 2,87 2,87 17,008 17,008 15,645 92.0%
LED
Totals: 3 1,36 1
31,361 28,846 92.0%
Measurement and Evaluation Report 97

Avista Idaho PY2024
Lighting Retrofit kW Savings Calculations
MQuantity Expected Adjusted Verified IkW
(Fixtures) IkW kW kW Realization
�=M�E
4L
F54T5HO to
34 26 236 148 0.43 3.67 3.68 1.97 53.5%
1L 148W
LED
4L
F54T5HO to
41 26 236 182 0.43 4.37 4.36 2.34 53.7%
1L 181W
LED
Totals: 8.04 8.04 4.31 53.6%
Results
For project#SSLP_82041 the kWh realization rate is 92.0% and the kW realization rate is 53.6%.
Verified Gross Savings, Realization Rates&Adjustments
Verified Verified kWh kW kWh IkW Therm
Measure kWh IkW Realization Realization Adjust- Adjust- Penalty
Savings Reduction Rate Rate ments ments
4L F54T5HO to
1L 148W LED 13,202 1.97 92.0% 53.5% 0 0.00 -200
4L F54T5HO to
1L 181W LED 15,645 2.34 92.0% 53.7% 0 0.00 -237
Totals: 28,846 4.31 92.0% 53.6% 0 0.00 -438
Expected savings calculations assumed 3,120 annual hours of operation, hours extrapolated for the
operating schedule collected during the on-site visit yielded approximately 2,870 annual hours and
slightly reduced realized kWh. Similarly, by default expected savings are calculated using an 80% peak
CF,though using the verified operating schedule the Evaluators calculated a 43%chance the lights
would be operating during peak hours, resulting in a lower verified peak W reduction.
Measurement and Evaluation Report 98

Avista Idaho PY2024
Project Number SSOP_113344
Project Background
The participant is a manufacturing facility that received incentives from Avista for replacing and existing
180hp DC motor and silicon-controlled rectifier with a 200hp AC induction motor controlled by a VFD.
M&V Methodology
The Evaluators reviewed all project documentation including plans, photos, and invoices to verify the
installation of rebated equipment. Verified savings were calculated using the following standard
algorithms, along with runtime data extrapolated from data logger.
kWhsavings = kWhpYe — kWhpost
kWhpre/post = kWpre/post X AOH r
V X Iavg,pre/post X Pfpre/post X y 3
kWpre/post = 1000
Where:
AOH =Annual Operating Hours
V =Voltage (nominal)
Iavg =Average current draw
Pf = Power Factor
pre = Indicates pre-implementation
post = Indicates post-implementation
Savings Parameters
Specific input parameters assumed in the analysis and confirmed by the Evaluators are:
Measure Parameters/Characteristics
MotorEfficient
Currentavg Power Factor Currentavg Voltage
71.8 0.8 44.0 0.98 480 8,424
Results
For project#SSOP_113344,the kWh realization rate is 100.0%and the kW realization rate is 100.0%.
Measurement and Evaluation Report 99

Avista Idaho PY2024
Verified Gross Savings& Realization Rates
Verified
kWh kWh Realization kW Realization
Savings Rate Rate
DC motor with silicon rectifier to AC induction
motor with VFD 402,286 11.91 100.0% 100.0%
Totals: 402,286 11.91 100.0% 100.0%
Measurement and Evaluation Report 100

Avista Idaho PY2024
Project Number SSOP_81734
Project Background
The participant is a communications office that received incentives from Avista for"grooming"their
telecom switch system, in which unneeded switches are removed from the network.
M&V Methodology
The Evaluators reviewed all project documentation including plans, photos, invoices and simulation
outputs,to verify the installation of rebated equipment.The Evaluators attempted to conduct a facility-
level billing analysis (Option C) using two years' worth of facility billing data and local weather data,
obtaining the following results:
Billing Regression Results
CDD Balance HDD Balance Pre-Period Post-Period kWh Savings
Point •. .. ..
55 50 4.2% 3,039 2,776 263
Savings Calculations
Calculations parameters used in the analysis and confirmed by the Evaluators are:
Model Fit
'Pre'model RI ..
0.77 0.81
Pre/Post Use and kWh Savings
Expected kWh Annual Pre Usage Annual Post Usage Verified kWh Realization Rate
Savings (kWh) (kWh) Savings
198,868 1 40,280 21,983 196,000 1 99%
Results
For project#SSOP_81734,the kWh realization rate is 99%.
Verified Gross Savings& Realization Rates
Verified
Telecom "Grooming" 198,868 N/A 99% N/A
Totals: 198,868 N/A 99% N/A
Measurement and Evaluation Report 101

Avista Idaho PY2024
Project Number SSOP_81611
Project Background
The participant is an assembly that received incentives from Avista for replacing existing hydraulic
motors with VFD AC-induction motors in their facility.The Evaluators verified the participant had
installed:
■ (1) VFD AC Motor replaced an existing hydraulic motor on the planer feed line
M&V Methodology
The Evaluators reviewed all project documentation including plans, photos, invoices and prescriptive
calculations used to arrive at ex ante savings estimates. On site,the Evaluators confirmed the
installation of the equipment and recorded nameplate information for verification. Existing logging data
was use to confirm the annual hours of operation. Savings were calculated using the following
algorithms:
kWhsavings = kWhbase — kWhee
kWh = kW x hours of operation
kW = V XlavgXPf X �
1000
Where:
Hours of operation =Annual Operating Hours
V =Voltage (nominal)
Iavg =Average current draw
Pf = Power Factor
Savings Parameters
Specific input parameters assumed in the analysis and confirmed by the Evaluators are:
Measure Parameters/Characteristics
Annual Input Outfeed Infeed CoolingOutfeed Cooling
Building Voltage Uptime% Amps Amps Amps PF Infeed PIP PF
Hours —7
8,760 472 45% 63.0 51.0 50.0 0.60 0.50 0.80
Savings Calculations
Baseline Efficient
Baseline kW Annual Baseline Efficient kW Annual Efficient Energy
Operating Energy Operating
Hours Hours
87.7 4,993 438,130 38.5 3,942 151,596 286,534
Measurement and Evaluation Report 102

Avista Idaho PY2024
Results
For project#SSOP_121533,the kWh realization rate is 100%.
Verified Gross Savings& Realization Rates
Measure Irerified
� kWh Savings kW Savings kWh Realization Rate IkW Realization Rate
VFD-controlled AC motors 286,724 49.00 100.% 100.0%
Totals: 286,724 49.00 100A 100.0%
Measurement and Evaluation Report 103

Avista Idaho PY2024
Project Number SSOP_117547
Project Background
The participant is a lodging facility that received incentives from Avista for replacing existing baseboard
heaters with efficient PTHP units, install insulation to the building's interior, and replace single-pane
windows with triple-pane vinyl windows.The Evaluators verified the participant had installed:
■ (25) inefficient baseboard PTAC units were replaced with (25) PTHP units
■ (30,118) sqft of uninsulated wall of R4 to (30,118) sqft of insulated walls of R19, ceiling of R49
and floors of R25
■ (568) sqft of U-0.58 and 0.75 SHGC value single-pane window units were replaced with (568)
sqft of U-0.29 and 0.26 SHGC value triple-paned vinyl windows on all sides of the building.
M&V Methodology
The Evaluators reviewed all project documentation including plans, photos, invoices, and simulation
outputs,to verify the installation of rebated equipment.The Evaluators attempted to conduct a facility-
level billing analysis (Option C) using nine months of pre and post conditions worth of facility billing data
and local weather data, however found that there was a statistically significant increase in use during
the post period when compared with the pre period. This indicated additional conflating factors beyond
weather(such as other changes to equipment, store operating hours or changes in behavioral patterns)
are affecting the energy consumption of the facility.
To verify savings,the Evaluators instead examined materials used to develop expected savings
estimates, and prescriptive engineering algorithms to verify ex ante estimates. The Evaluators found all
ex ante assumptions and inputs to be reasonable and appropriate, and prescriptive calculations yielded
similar kWh savings estimated, corroborating savings claims.
Savings Parameters
Specific input parameters assumed in the analysis and confirmed by the Evaluators are:
Measure Parameters/Characteristics—HVAC Units
Heating Baseline Heating Efficient Air
AC Unit System AC Cop System Location Conditio- Heating
Unit Size COP Type Unit Unit .- ning
Size Size Size
9,000 8,100 9,000 Baseboar
2,000 W BTU 1 ER BTU BTU 3.4 HP d Units Electric HP
Measurement and Evaluation Report 104

Avista Idaho PY2024
Measure Parameters/Characteristics—Insulation
Baseline
Wall .. .. DD CDDConditioning
Ft2 Ceiling
30,118 1 4 4 4 30,118 19 49 25 6,276 899 Electric HP
Measure Parameters/Characteristics—Window Panes
Efficient Air Heating
N Conditioning
568 0.58 0.75 0.653 568 0.29 0.26 0.226 Entire Electric HP
Facility
Results
For project#SSOP-117547,the kWh realization rate is 100.0%.
Verified Gross Savings& Realization Rates
Verified
Measure kWh kW kWh Realization Therm Realization
Savings Savings Rate Rate
PTAC/PTHP,window pane, insulation 288,762 N/A 100.0% N/A
replacement
Totals: 288,762 N/A 100.0% N/A
Measurement and Evaluation Report 105

Avista Idaho PY2024
Project Number SSOP_82111
Project Background
The participant is an assembly that received incentives from Avista for removing six (6) existing wall-
mounted electric resistance space heaters and three (3) mobile electric space heaters. On site, the
Evaluators had confirmed that these heaters had been replaced with steam-powered heaters.
M&V Methodology
The Evaluators reviewed all project documentation including plans, photos, invoices and prescriptive
calculations used to calculate expected savings. During the site visits,the Evaluators confirmed that the
existing ER heaters had been replaced with steam-powered heaters, and that heaters operate only when
the air temperature drops below 50 degrees Fahrenheit. Energy savings comes from the removal of
electric equipment and is calculated as follows:
VXIavgxPfx �
kW = 1000
kWh = kW x hours of operation
kWhsavings = kWhwall + kWh-mobile
Where:
Hours or operation =Annual Operating Hours (5,464)
V =Voltage (nominal) (472 volts)
Iavg =Average current draw (22.4 amps)
Pf = Power Factor(0.9)
Savings Calculations
Specific input parameters assumed in the analysis and confirmed by the Evaluators are shown in the
table below. Annual operating hours are based on TMY data taken from station NSRDB 241029 in
Grangeville, ID.
Measure Parameters/Characteristics
Unit Type kW ON
Wall 16.5 5,510 6 544,874
Mobile 4.5 5,510 3 74,385
Total: 619,259
Results
For project#SSOP_82111,the kWh realization rate is 100.0%.
Measurement and Evaluation Report 106

Avista Idaho PY2024
Verified Gross Savings& Realization Rates
Ferified
Measure kWh Savings kW Savings kWh Realization Rate IkW Realization Rate
EEM Heaters 619,259 37.46 100.0% 100.0%
Totals: 619,259 37.46 100.0% 100.0%
Measurement and Evaluation Report 107

APPENDIX B - 2024 NATURAL GAS IMPACT EVALUATION REPORT
MM
Evaluation, Measurement and
Verification ( EM &V) of Avista Idaho
Natural Gas PY2024 Residential,
Low-Income, and Nonresidential
Energy Efficiency Programs
SUBMITTED TO: AVISTA UTILITIES
SUBMITTED ON : AUGUST 19, 2025
SUBMITTED BY: ADM ASSOCIATES, INC.
ADM Associates, Inc Avista Utilities
3239 Ramos Circle 1411 E. Mission Ave.
Sacramento,CA 95827 Spokane, WA 99252
2024 Idaho Annual Conservation Report Appendices

Avista Idaho PY2024
Table of Contents
1. Executive Summary............................................................................................................................. 1
1.1 Savings Results............................................................................................................................................1
1.2 Conclusions and Recommendations...........................................................................................................2
2. General Methodology...........................................................................................................................7
2.1 Glossary of Terminology.............................................................................................................................7
2.2 Summary of Approach................................................................................................................................8
3. Residential Impact Evaluation Results...............................................................................................23
3.1 Simple Verification Results.......................................................................................................................23
3.2 Program-Level Impact Evaluation Results................................................................................................25
4. Low-Income Impact Evaluation Results............................................................................................44
4.1 Program-Level Impact Evaluation Results................................................................................................44
5. Nonresidential Impact Evaluation Results.........................................................................................46
5.1 Verification Results...................................................................................................................................46
5.2 Program-Level Impact Evaluation Results................................................................................................47
6. Appendix A: Summary of Survey Respondents.................................................................................56
Tables of Contents and Tables ii

Avista Idaho PY2024
List of Tables
Table 1-1: Residential Verified Impact Savings by Program .........................................................................1
Table 1-2: Low-Income Expected Savings by Program .................................................................................1
Table 1-3: Nonresidential Verified Impact Savings by Program ...................................................................2
Table 1-4: Impact Evaluation Activities by Program and Sector...................................................................2
Table 2-1: Document-based Verification Samples and Precision by Program ...........................................12
Table 2-2: Survey-Based Verification Sample and Precision by Program...................................................13
Table 3-1: Residential Verified Impact Savings by Program .......................................................................23
Table 3-2: Summary of Survey Response Rate...........................................................................................24
Table 3-3: State-Level Simple Verification Precision by Program...............................................................24
Table 3-4: Mixed State-Level Simple Verification Precision by Program....................................................24
Table 3-5:Appliances Program ISRs by Measure........................................................................................24
Table 3-6: Shell Program Measures............................................................................................................26
Table 3-7: Shell Program Verified Natural Gas Savings ..............................................................................27
Table3-8: Shell Program Costs...................................................................................................................28
Table 3-9: ENERGY STAR' Homes Program Measures ...............................................................................31
Table 3-10: Fuel Efficiency Program Measures...........................................................................................32
Table 3-11: Fuel Efficiency Program Verified Natural Gas Penalty.............................................................32
Table 3-12:Appliances Program Measures................................................................................................33
Table 3-13:Appliances Program Verified Natural Gas Savings...................................................................34
Table 3-14:Appliances Program Costs .......................................................................................................34
Table 3-15:Appliances Verification Survey ISR Results..............................................................................35
Table 3-16: Measures Considered for Billing Analysis,Appliances Program..............................................36
Table 3-17: Measure Savings, Appliances Program....................................................................................37
Table 3-18: Midstream Program Measures................................................................................................38
Table 3-19: Midstream Program Verified Natural Gas Savings ..................................................................38
Table 3-20: Midstream Program Costs by Measure...................................................................................39
Table 3-21. Furnace Billing Analysis Results...............................................................................................40
Table 3-22: Home Energy Audit Program Verified Natural Gas Savings.....................................................41
Table 3-23: Home Energy Audit Program Costs by Measure......................................................................41
admenergy.com 13239 Ramos Circle, Sacramento, CA 95827 1 916.363.8383 iii

Avista Idaho PY2024
Table 3-24: On Bill Repayment Program Claimed Natural Gas Savings......................................................43
Table 3-25: On Bill Repayment Program Claimed Costs by Measure.........................................................43
Table 4-1: Low-Income Verified Impact Savings by Program .....................................................................44
Table 4-2: Low-Income Program Measures................................................................................................45
Table 4-3: Low-Income Program Claimed Natural Gas Savings..................................................................45
Table 4-4: Low-Income Program Costs.......................................................................................................45
Table 5-1: Non-Residential Verified Impact Savings by Program ...............................................................46
Table 5-2: Non-Residential Program-level Verification Precision...............................................................47
Table 5-3: Prescriptive HVAC Program Measures.......................................................................................48
Table 5-4: Prescriptive HVAC Program Verified Natural Gas Savings.........................................................48
Table 5-5: Prescriptive Shell Program Measures........................................................................................49
Table 5-6: Prescriptive Shell Program Verified Natural Gas Savings ..........................................................49
Table 5-7: Prescriptive Shell Program Costs by Measure ...........................................................................49
Table 5-8: Prescriptive Shell Program Verification Precision......................................................................50
Table 5-9: Non-Residential Midstream Program Measures .......................................................................51
Table 5-10: Non-Residential Midstream Program Verified Therms Savings...............................................52
Table 5-11: Non-Residential Midstream Program Incentives.....................................................................52
Table 5-12: Non-Residential Midstream Program Verification Precision...................................................52
Table 5-13: Site-Specific Program Verified Natural Gas Savings.................................................................54
Table 5-14: Site-Specific Program Costs .....................................................................................................54
Table 5-15: Site-Specific Expected,Adjusted and Verified Therm Savings by Project ...............................55
Table 5-16: Site-Specific Impact Summary .................................................................................................55
Table 6-1:Type and Number of Measures Received by Respondents.......................................................56
Table 6-2: Survey Respondent Home Characteristics.................................................................................57
admenergy.com 13239 Ramos Circle, Sacramento, CA 95827 1 916.363.8383 iv

Avista Idaho PY2024
1. Executive Summary
This report is a summary of the Residential, Low-Income, and Nonresidential Gas Evaluation,
Measurement, and Verification (EM&V) effort of the 2024 program year(PY2024) portfolio of
programs for Avista Corporation (Avista) in the Idaho service territory.The evaluation was
administered by ADM Associates, Inc. (herein referred to as the "Evaluators").
1.1 Savings Results
The Evaluators conducted an impact evaluation for Avista's Residential, Low-Income, and
Nonresidential programs for PY2024.The Residential portfolio savings amounted to 185,712 Therms
with a 226.22% realization rate.The Low-Income portfolio savings amounted to 1,380 Therms;
however,the Evaluators did not conduct an impact evaluation for this sector and present the
savings claimed for reporting purposes.The Nonresidential portfolio savings amounted to 33,187
Therms with a 92.7% realization rate.The Evaluators summarize the Residential, Low-Income, and
Nonresidential portfolio verified savings in Table 1-1 through Table 1-3, respectively.
Table 1-1: Residential Verified Impact Savings by Program
Program Expected Savings Verified Savings Verified Realization
(Therms) (Therms) Rate
Shell 18,414.11 21,429.50 116.38%
Fuel Efficiency' NA NA NA
ENERGY STAR HomeS2 NA NA NA
Appliances 11,973.57 19,967.99 166.77%
Midstream 51,706.71 144,314.62 279.10
Home Energy Audit 0 NA NA
On Bill Repayment 0 NA NA
Total 82,094.39 185,712.11 226.22%
Table 1-2:Low-Income Expected Savings by Program
Program Expected Savings Verified Savings Verified Realization
(Therms) (Therms) Rate
Low-Income 1,380.11 NA NA
Total 1,380.11 NA NA
1 The Fuel Efficiency Program displayed a verified Therms penalty of 5,620.00 Therms due to fuel conversion measures. For the
purposes of this report,this penalty is not included in the overall metrics of natural gas-saving energy efficiency measures.
2 The ENERGY STAR Homes Program displayed a verified Therms savings of 0.00 Therms for the electric measures; no dual fuel
measures were rebated in PY2024.
Measurement and Evaluation Report 1

Avista Idaho PY2024
Table 1-3:Nonresidential Verified Impact Savings by Program
Program Expected Savings Verified Savings Verified Realization
(Therms) (Therms) Rate
Shell 3,600 3,600 100.00%
Midstream 26,804 24,769 92.4%
Site-Specific 5,408 4,818 89.10%
Total 35,812 33,187 92.7%
Table 1-4 summarizes the gas programs offered to Residential, Low-Income, and Nonresidential
customers in the Idaho Avista service territory in PY2024 as well as the Evaluators' evaluation tasks
and impact methodology for each program.
Table 1-4:Impact Evaluation Activities by Program and Sector
ImpactDatabase Review Survey Verification
Methodology
Residential Shell ✓ Avista TRM/RTF LIES
Residential ENERGY STAR® ✓ Avista TRM/RTF UES
Homes
Avista TRM/RTF
Residential Appliances `� UES/Billing Analysis
Residential Midstream ✓ RTF UES/Billing
Analysis
Low-Income Low-Income ✓ Avista TRM
Nonresidential HVAC ✓ RTF,Avista TRM
Nonresidential Shell ✓ Avista TRM
Nonresidential Midstream ✓ RTF,Avista TRM,
IPMVP Option A
Nonresidential Site-Specific ✓ IPMVP Options
1.2 Conclusions and Recommendations
The following section details the Evaluators' conclusions and recommendations for each the
Residential Portfolio, Low-Income Portfolio, and Nonresidential Portfolio program evaluations.
1.2.1 Conclusions
The following section details the Evaluator's findings resulting from the program evaluations for each
the Residential Portfolio, Low-Income Portfolio, and Nonresidential Portfolio.
1.2.1.1 Residential Programs
The Evaluators provide the following conclusions regarding Avista's Residential gas programs:
The Evaluators found the Residential portfolio to demonstrate a total of 185,712 therms with a
realization rate of 226.22%.
The Residential Portfolio impact evaluation resulted in a realization rate of 226.22% due to
improvements in the Midstream Program estimation of savings.The largest contributor to the
high Midstream Program realization rate was the calculation of gas furnace savings via a billing
analysis, instead of a deemed savings methodology.The Evaluators' billing analysis found that
Measurement and Evaluation Report 2

Avista Idaho PY2024
efficient gas furnace installation was associated with average annual savings of 90.0 therms per
household,which is nearly triple the ex-ante expected savings.The Evaluators would
recommend Avista calculate expected furnace savings based on billing analysis data in the
future. For other Midstream Program measures,Avista resolved PY2023 recommendations for
the program implementer to incorporate RTF-implemented market practice baseline.The
Evaluators utilized engineering algorithms to evaluate this program based on purchased
equipment efficiency level.The Evaluators also applied RTF market practice baseline equivalents
to the engineering algorithms in order to maintain consistency with evaluation methods
between the downstream and midstream programs, while taking into account the often-higher
efficiency values of the purchased equipment. PY2024 results show a marked improvement in
expected savings calculations methodology from the previous year.The Evaluators recommend
Avista and the Midstream Program implementer continue incorporating Regional Technical
Forum (RTF) market practice baselines to estimate regional savings for non-furnace measures.
Additionally,the Appliance Program displayed 166.77% realization rate due to a smart
thermostat billing analysis indicating higher than expected savings for the measure, the largest
contributor to savings for the Appliance Program.
■ In PY2023,the Evaluators conducted verification surveys via web survey to collect information
from customers who participated in the Appliances Program. For the purposes of this report,
the PY2023 survey response results were used to estimate in-service rate adjustments in the
PY2024 evaluation, as survey efforts were not completed in PY2024.The Evaluators collected
information including the functionality of the efficient equipment, and the functionality of the
replaced equipment.The Evaluators calculated in-service rates for the measures within these
programs in order to apply findings to the verified savings results for each program.The
Evaluators will conduct a full survey effort in PY2025, once per biennium.
■ The Shell Program displayed verified savings of 21,430 therms with a realization rate of 116.38%
against the expected savings for the program.The realization rate for the natural gas savings in
the Shell Program deviates from 100%due primarily to the fact that RTF unit energy saving
(UES)values are differentiated by heating type and climate zone, while Avista TRM prescriptive
savings values are less granular. In addition, in a few instances, ex-ante savings were primarily
claimed as electric while ex-post verified savings were claimed for gas following space heating
type verification. Furthermore, missing verified R-values, square footage, and appropriate
measure of units (square footage)from sampled projects led to variation in realization rate for
each measure type.
■ The ENERGY STAR Homes Program displayed no participation in PY2024 and therefore no
impact evaluation was conducted on the program.
■ The Fuel Efficiency Program gas impacts are not claimed in the Idaho Gas report, however,the
Evaluators found that the program resulted in a 5,620 therms penalty,which is detailed in the
Idaho Electric impact evaluation report.Therms penalties are not aggregated into this report's
Residential portfolio impact evaluation and instead are reported here for planning purposes.
■ The Appliance Program displayed a realization rate of 166.77%with 19,968 therms saved in
PY2024.The realization rate for the natural gas savings in the Appliance Program is greater than
Measurement and Evaluation Report 3

Avista Idaho PY2024
100%due to the billing analysis conducted for smart thermostats, the largest contributor to
savings through the Appliance Program. However,the Evaluators also note discrepancies
between the Avista TRM and RTF UES Savings values for smart thermostats and errors with the
clothes washer claimed savings.
■ The Midstream Program displayed a 279.10% realization with 144,314.62 therms saved.The
Evaluators conducted a billing analysis to calculate verified gas furnace savings and that yielded
average annual savings of 90.0 therms per furnace, nearly triple Avista's ex-ante estimates.
Across all furnaces this contributed to verified savings of 139,326 with a realization rate of
298.14%. For all other Midstream measures there was a marked improvement in expected
savings calculations methodology from the previous year.The Evaluators reviewed the Energy
Solutions implementer expected savings values along with verified tracking data to estimate net
adjusted program savings for those measures.To calculate verified savings,the Evaluators ran a
billing analysis for furnaces and for all other measures utilized industry-standard engineering
algorithms using purchased equipment efficiency values and RTF-defined market practice
baseline values, where appropriate.
■ The Home Energy Audit Program was evaluated by attempting a census billing analysis to
estimate the impacts of the education efforts of the Home Energy Audit Program. However,this
effort did not result in statistically significant natural gas impacts. The Evaluators recommend re-
attempting a billing analysis in PY2025 with additional participant data.
1.2.1.2 Low-Income Programs
The Evaluators provide the following conclusions regarding Avista's Low-Income natural gas
programs:
■ The Evaluators did not complete an impact evaluation of the Low-Income Program in PY2024
and therefore do not estimate verified savings for the program or sector. However,for reporting
purposes,the Evaluators summarize Avista's claimed savings for the program in PY2024.
1.2.1.3 Nonresidential Programs
The Evaluators provide the following conclusions regarding Avista's Nonresidential gas programs:
■ There was no participation in the HVAC program during PY2024.
■ The verified savings for the Shell program are 3,600 Therms with a realization rate of 100.0%, as
displayed in Table 5-5. Evaluators did not find any deviations from the Avista TRM UES.
■ The verified savings for the Midstream program are 24,769 Therms with a realization rate of
92.4%.
■ The verified savings for the Site-Specific Program are 4,818 Therms with a realization rate of
89.1%.
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1.2.2 Recommendations
The following section details the Evaluator's recommendations resulting from the program
evaluations for the Residential Portfolio, Low-Income Portfolio, and Nonresidential Portfolio.
1.2.2.1 Residential Programs
The Evaluators offer the following recommendations regarding Avista's Residential natural gas
programs:
■ The Evaluators found a handful of instances in which the rebated equipment did not meet the
program minimum requirements for efficiency.The Evaluators recommend Avista check the
source AHRI documentation and product level documentation to verify efficiency prior to
incentivizing installation of the measure. For example,eight smart thermostats did not qualify
for RTF savings.
■ In the Shell Program,the Evaluators found that verified attic insulation,wall insulation, and
window measure savings displayed varying realization rates at the project level primarily due to
differences between the granularity of the Avista TRM and RTF prescriptive savings values.The
RTF differentiates savings by heating type, R-value, and climate zone while Avista provides more
generalized savings estimates. With appropriate weighting, such generalized savings estimates
can be valid; however, several Shell Program savings values currently presented in the Avista
TRM do not seem to align perfectly with average participant characteristics.This discrepancy
between Avista and RTF savings categorization granularity led to a low realization rate for attic
insulation and window measures.The Evaluators recommend Avista update the Avista TRM
value to reflect a more accurate weighted average of participation home characteristics.The
Evaluators also found that some window measures contained discrepancies in unit quantity and
attic insulation projects that did not clearly provide R-Values in the documentation provided.
Additionally,three window projects did not provide sufficient documentation to verify square
footage or even the quantity of windows and two sliding glass door projects were found to claim
16.7 kWh and Therms savings. Based on these findings,the Evaluators recommend Avista verify
the project meets the insulation or efficiency requirements through documentation provided in
project applications and request additional information if the original documentation does not
summarize the efficiency and square footage of the project being completed.The Evaluators
also recommend Avista conduct measure-level verification efforts to ensure proper fuels are
being claimed in the tracking datasets.
■ In the Appliances Program,the Evaluators recommend Avista update the clothes dryer Avista
TRM value to correctly assign 1.60 therms savings for the measure, as reflected in the RTF.
Currently,the Avista TRM reflects 2.72 therms/unit. Additionally,The Evaluators recommend
Avista update the front load clothes washer Avista TRM value to correctly convert 119.99
kWh/unit to 2.40 therms/unit. Currently,the Avista TRM reports 6.03 therms/unit.
■ The Evaluators note that the RTF defines an annual savings of 11.7 therms for all gas smart
thermostat measure specifications defined in the Connected Thermostats RTF workbook.
Although this finding did not impact the realization rate of the program in PY2024 due to
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statistically significant savings identified for smart thermostats through the billing analysis
method, the Evaluators recommend Avista update the assumed claimed savings values in the
Avista TRM to avoid discrepancies in future smart thermostat savings calculations.
■ The Evaluators also found one sampled smart thermostat model that did not meet the minimum
RTF qualifications for savings, although Avista had assigned the maximum savings value to that
project.The Evaluators recommend Avista verify each smart thermostat model meets the RTF
requirements for regional savings compared to the market practice baseline or provide a list of
qualified products for customers to select from when participating in this program.
■ The Evaluators recommend Avista estimate natural gas savings for the Midstream Program's
gas furnace measure based on billing analysis results.The Evaluators 2024 gas furnace billing
analysis yielded annual savings of 90.0 therms,for a 298.14% realization rate for the measure.
Furnace installation by Avista customers in Idaho seems to be associated with substantially
higher gas savings than reported by the RTF Residential Gas Furnace LIES workbook. To
maximize the accuracy of reported savings,future ex-ante savings estimates should likely be
based on billing analysis results instead of deemed savings.
■ The Evaluators recommend Avista and the Midstream Program implementer continue
incorporating Regional Technical Forum market practice baseline to estimate regional savings
for all non-furnace measures in the Midstream Program. Were the same measures rebated
downstream instead of midstream, savings would be evaluated via a comparison of efficient
technology against market practice baselines in the Pacific Northwest.As such,the Evaluators
believe relying on regional market practice baselines a valid methodology that should be used to
estimate and evaluate non-furnace Midstream measures moving forward.
■ The Evaluators recommend re-attempting a billing analysis in PY2025 for the Home Energy
Audit Program with additional participant billing data.
1.2.2.2 Low-Income Programs
The Evaluators offer the following recommendations regarding Avista's Low-Income natural gas
programs:
■ The Evaluators did not complete an evaluation for the Low-Income Program in PY2024 and
therefore do not have any recommendations currently.
1.2.2.3 Nonresidential Programs
The Evaluators offer the following recommendations regarding Avista's Nonresidential natural gas
programs:
■ For the Midstream Program:
o The Evaluators found that all measures claimed savings were calculated based on
assumed average equipment sizing, whereas verified savings calculations were carried
out using standard engineering algorithms. Although relative magnitudes of savings per
project generally aligned with algorithm-based results,the Evaluators recommend the
program implementers adjust assumed average sizing to better reflect program
participant purchasing behaviors.
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2-General Methodology
The Evaluators performed an impact evaluation on each of the programs summarized in Table 1-4.The
Evaluators used the following approaches to calculate energy impacts as defined by the International
Performance Measurement and Verification Protocols (IPMVP)3 and the Uniform Methods Project
(UMP)4:
■ Simple verification (web-based surveys supplemented with phone surveys)
■ Document verification (review project documentation)
■ Deemed savings (RTF UES and Avista TRM values)
■ Whole facility billing analysis (IPMVP Option Q
■ Appropriate IPMVP Option (for Site-Specific, depending on project)
The Evaluators completed the above impact tasks to calculate the natural gas savings associated with
measures installed and projects completed in the Idaho Avista service territory.
The M&V methodologies are program-specific and determined by previous Avista evaluation
methodologies as well as the relative contribution of a given program to overall portfolio-wide energy
efficiency impacts. Besides drawing on IPMVP,the Evaluators also reviewed relevant information on
infrastructure,framework, and guidelines set out for EM&V work in several guidebook documents that
have been published over the past several years.These include the following:
■ Northwest Regional Technical Forum (RTF)'
■ National Renewable Energy Laboratory (NREL), United States Department of Energy (DOE)
The Uniform Methods Project (UMP): Methods for Determining Energy Efficiency Savings for
Specific Measures,April 2013'
■ International Performance Measurement and Verification Protocol (IPMVP) maintained by
the Efficiency Valuation Organization (EVO) with sponsorship by the U.S. Department of
Energy(DOE)'
The Evaluators kept data collection instruments, calculation spreadsheets, and monitored/survey data
available for Avista records.
2.1 Glossary of Terminology
As a first step to detailing the evaluation methodologies,the Evaluators have provided a glossary of
terms to follow:
3 https://www.nrel.gov/docs/fy02osti/31505.pdf
4 https://www.nrel.gov/docs/fyl8osti/70472.pdf
6 https://rtf.nwcouncil.org/measures
6 Notably,The Uniform Methods Project (UMP) includes the following chapters authored by ADM. Chapter 9 (Metering Cross-
Cutting Protocols)was authored by Dan Mort and Chapter 15(Commercial New Construction Protocol)was Authored by Steven
Keates.
7 Core Concepts: International Measurement and Verification Protocol.EVO 100000—1:2016,October 2016.
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■ Deemed Savings—An estimate of an energy savings outcome (gross savings)for a single unit of
an installed energy efficiency measure.This estimate (a) has been developed from data sources
and analytical methods that are widely accepted for the measure and purpose and (b) are
applicable to the situation being evaluated.
■ Expected Savings—Calculated savings used for program and portfolio planning purposes.
• Adjusted Savings—Savings estimates after database review and document verification has been
completed using deemed unit-level savings provided in the Avista TRM. It adjusts for such
factors as data errors and installation rates.
■ Verified Savings—Savings estimates after the updated unit-level savings values have been
updated and energy impact evaluation has been completed, integrating results from billing
analyses and appropriate RTF LIES and Avista TRM values.
■ Gross Savings—The change in energy consumption directly resulting from program-related
actions taken by participants in an efficiency program, regardless of why they participated.
■ Free Rider—A program participant who would have implemented the program measure or
practice in absence of the program.
■ Net-To-Gross—A factor representing net program savings divided by gross program savings that
is applied to gross program impacts to convert them into net program load impacts.
■ Net Savings—The change in energy consumption directly resulting from program-related
actions taken by participants in an efficiency program,with adjustments to remove savings due
to free ridership.
■ Non-Energy Benefits—Quantifiable impacts produced by program measures outside of energy
savings (comfort, health and safety, reduced alternative fuel, etc.).
■ Non-Energy Impacts—Quantifiable impacts in energy efficiency beyond the energy savings
gained from installing energy efficient measures (reduced cost for operation and maintenance
of equipment, reduced environmental and safety costs, etc.).
2.2 Summary of Approach
This section presents our general cross-cutting approach to accomplishing the impact evaluation of
Avista's Residential, Low-Income, and Nonresidential programs listed in Table 1-4.The Evaluators start
by presenting our general evaluation approach.This chapter is organized by general task due to overlap
across programs.
The Evaluators outline the approach to verifying, measuring, and reporting the residential portfolio
impacts as well as summarizing potential program and portfolio improvements.The primary objective of
the impact evaluation is to determine ex-post verified net energy savings.
Our general approach for this evaluation considers the cyclical feedback loop among program design,
implementation, and impact evaluation. Our activities during the evaluation estimate and verify annual
energy savings and identify whether a program is meeting its goals.These activities are aimed to provide
guidance for continuous program improvement and increased cost effectiveness for the 2025 program
year.
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The Evaluators employed the following approach to complete impact evaluation activities for the
programs.The Evaluators define three major approaches to determining net savings for Avista's
programs:
■ A Deemed Savings approach involves using stipulated savings for energy conservation measures
for which savings values are well-known and documented.These prescriptive savings may also
include an adjustment for certain measures, such as lighting measures in which site operating
hours may differ from RTF values.
■ A Billing Analysis approach involves estimating energy savings by applying a linear regression to
measured participant energy consumption utility meter billing data. Some billing analyses
included billing data from nonparticipant customers as a control grup.This approach does not
require on-site data collection for model calibration.This approach aligns with the IPMVP
Option C.
■ A Custom approach, used for the Site-Specific program involves selecting the appropriate IPMVP
option to apply to the specific measure or project.Typically this is Option A as most projects in
the program are lighting retrofits, however Options B, C and D are also employed, depending
upon the project. Specific methods are discussed in each site report.
The Evaluators accomplished the following quantitative goals as part of the impact evaluation:
■ Verify savings with 10% precision at the 90%confidence level;
■ Where appropriate, apply the RTF to verify measure impacts; and
■ Where available data exists,conduct billing analysis with a suitable comparison group to estimate
measure savings.
For each program,the Evaluators calculated adjusted savings for each measure based on the Avista TRM
and results from the database review.The Evaluators calculated verified savings for each measure based
on the RTF UES,Avista TRM, or billing analysis in combination with the results from document review.
Reported Database Adjusted Document' Evaluate
Savings Review savings Review Savings
The Evaluators assigned methodological rigor level for each measure and program based on its
contribution to the portfolio savings and availability of data.
The Evaluators applied billing analysis results to determine evaluated savings only for measures where
savings could be isolated (that is, where sufficient participants could be identified who installed only
that measure). Program-level realization rates for the Appliances and Midstream programs incorporate
billing analysis results for some measures.
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2.2.1 Database Review
At the outset of the evaluation, the Evaluators reviewed the databases to ensure that each program
tracking database conforms to industry standards and adequately tracks key data required for
evaluation.
Measure-level net savings were evaluated primarily by reviewing measure algorithms and values in the
tracking system to assure that they are appropriately applied using the Avista TRM.The Evaluators then
aggregated and cross-checked program and measure totals.
The Evaluators reviewed program application documents for a sample of incented measures to verify
the tracking data accurately represents the program documents.The Evaluators ensured each home
installed measures that meet or exceed program efficiency standards.
2.2.2 Verification Methodology
In this section,the Evaluators summarize the verification methods used to ensure project-level details
were indeed completed and to the efficiency levels detailed in the program-level tracking data.
2.2.2.1 Sampling Methodology
The Evaluators summarize the methods for each verification effort:
■ Sampling methodology for most programs
■ Sampling methodology for the Site-Specific Program
■ Document-based verification
■ Survey-based verification
■ On-site visits
The Evaluators verified a sample of participating projects for detailed review of the installed measure
documentation and development of verified savings.The Evaluators verified tracking data by reviewing
invoices and surveying a sample of participant customer households/businesses.The Evaluators also
conducted a verification survey for program participants.
The Evaluators used the following equations to estimate sample size requirements for each program and
fuel type. Required sample sizes were estimated as follows:
Equation 2-1 Sample Size for Infinite Sample Size
n _ (Z x CV Z
ld )
Equation 2-2 Sample Size for Finite Population Size
n
no = l
1 + (N
Where,
■ n =Sample size
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■ Z =Z-value for a two-tailed distribution at the assigned confidence level.
■ CV = Coefficient of variation
■ d = Precision level
■ N = Population
For a sample that provides 90/10 precision,Z= 1.645 (the critical value for 90%confidence) and d=0.10
(or 10% precision).The remaining parameter is CV, or the expected coefficient of variation of measures
for which the claimed savings may be accepted. A CV of.5 was assumed for residential programs due to
the homogeneity of participation',which yields a sample size of 68 for an infinite population. Sample
sizes were adjusted for smaller populations via the method detailed in Equation 2-2.
2.2.2.2 Sampling Methodology for the Site-Specific Program
For the Site-Specific program, Simple Random Sampling is not an effective sampling methodology as the
CV values observed in business programs are typically very high because the distributions of savings are
generally positively skewed. Often, a relatively small number of projects account for a high percentage
of the estimated savings for the program.
To address this situation, we use a sample design for selecting projects for the M&V sample that
considers such skewness. With this approach, we select several sites with large savings for the sample
with certainty and take a random sample of the remaining sites. To improve precision, non-certainty
sites are selected for the sample through systematic random sampling.That is, a random sample of sites
remaining after the certainty sites have been selected is selected by ordering them according to the
magnitude of their savings and using systematic random sampling. Sampling systematically from a list
that is ordered according to the magnitude of savings ensures that any sample selected will have some
units with high savings, some with moderate savings, and some with low savings. Samples cannot result
in concentrations of sites with atypically high savings or atypically low savings. Specific sampling
characteristics are shown in the Site-Specific section of this report.
The following sections describe the Evaluator's methodology for conducting document-based
verification and survey-based verification.
2.2.2.3 Document-Based Verification
The Evaluators requested rebate documentation for a subset of participating customers.These
documents included invoices, rebate applications, pictures, and AHRI certifications for the following
programs:
■ Shell Program
■ Fuel Efficiency Program
■ Appliances Program
s Assumption based off California Evaluation Framework:
https://www.cpuc.ca.gov/uploaded Files/CPUC_Public_Website/Content/Utilities_and_I ndustries/Energy/Energy_Programs/De
mand_Side_Management/EE_and_Energy_Savings_Assist/CAEvaluationFramework.pdf
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■ Midstream Program
■ Shell Program (Nonresidential)
■ Midstream Program (Nonresidential)
This sample of documents was used to cross-verify tracking data inputs. In the case the Evaluators found
any deviations between the tracking data and application values,the Evaluators reported and
summarized those differences in the Database Review sections presented for each program in Section
3.2 and Section 5.1.
The Evaluators developed a sampling plan that achieves a sampling precision of±10% at 90%statistical
confidence—or"90/10 precision"—to estimate the percentage of projects for which the claimed savings
are verified or require some adjustment.
The Evaluators developed the following samples for each program's document review using Equation
2-1 and Equation 2-2.The Evaluators ensured representation in each state and fuel type for each
measure.
Table 2-1:Document-based Verification Samples and Precision by Program
Sample
Sector Program Gas Population (With Finite Precision at 90%
Population Cl
Residential Shell 520 68 90%±9.31%
Residential Appliances 509 63 90%±9.71%
Residential Midstream 89 89 90%±0.00%
Low-Income Low-Income 39 NA NA
Non-Residential Shell 5 5 90%±0.00%
Non-Residential Midstream 112 105 90%±9.27%
'Assumes sample size of 68 for an infinite population, based on CV(coefficient of variation)=0.5,d(precision)=10%,Z(critical
value for 90%confidence)=1.645.
The table above represents the number of rebates in Idaho service territory only.The Evaluators ensured
representation of state and fuel type in the sampled rebates for document verification.
2.2.2.4 Survey-Based Verification
The Evaluators conducted survey-based verification for the Appliances Program in 2023 and applied
those results for PY2024.The primary purpose of conducting a verification survey is to confirm that the
measure was installed and is still currently operational and whether the measure was early retirement
or replace-on-burnout.
The Evaluators summarize the final sample sizes of sampled Idaho Gas Avista projects shown in Table
2-2 for the programs listed.The Evaluators developed a sampling plan that achieved a sampling
precision of±9.6% at 90%statistical confidence for ISRs estimates at the measure-level during web-
based survey verification.
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Table 2-2:Survey-Based Verification Sample and Precision by Program
• . . Precision at •0 , CI
Residential Appliances 115 43 90%±9.6%
The Evaluators implemented a web-based survey to complete the verification surveys.The findings from
these activities served to estimate ISRs for each measure surveyed.These ISRs were applied to
verification sample desk review rebates towards verified savings, which were then applied to the
population of rebates.The measure-level ISRs resulting from the survey-based verification are
summarized in Section 3.1.
2.2.2.5 Site-Specific Verification
For sampled projects in the Site-Specific program,the Evaluators conducted onsite visits to the facilities
to verify installation, collected facility characteristic and collected any data needed to conducted savings
calculations. Further details are available in the Site-Specific chapter.
2.2.3 Impact Evaluation Methodology
The Evaluators employed the following approach to complete impact evaluation activities for the
programs.The Evaluators define two major approaches to determining net savings for Avista's
programs:
■ Deemed Savings
■ Billing Analysis (IPMVP Option C)
The Site-Specific program also employed various IPMVP options, deepening upon the project and
measure, and is discussed separately as it differs in approach from the approaches used in the
remainder of the portfolio. In the following sections,the Evaluators summarize the general guidelines
and activities followed to conduct each the deemed savings and billing analyses approaches above.
2.2.3.1 Deemed Savings
This section summarizes the deemed savings analysis method the Evaluators employed for the
evaluation of a subset of measures for each program.The Evaluators completed the validation for
specific measures across each program using the RTF unit energy savings (UES)values, where available.
The Evaluators ensured the proper measure unit savings were recorded and used in the calculation of
Avista's ex-ante measure savings.The Evaluators requested and used the technical reference manual
Avista employed during calculation of ex-ante measure savings (Avista TRM).The Evaluators
documented any cases where recommended values differed from the specific unit energy savings
workbooks used by Avista.
In cases where the RTF has existing unit energy savings (UES) applicable to Avista's measures,the
Evaluators verified the quantity and quality of installations and applied the RTF's UES to determine
verified savings.
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2.2.3.2 Billing Analysis
This section describes the billing analysis methodology employed by the Evaluators as part of the impact
evaluation and measurement of energy savings for measures with sufficient participation. When
possible based on available data, Evaluators performed billing analyses with a matched control group
and utilized a quasi-experimental method of producing a post-hoc control group. In program designs
where treatment and control customers are not randomly selected at the outset, such as for
downstream rebate programs, quasi-experimental designs are required. If relevant non-participant
billing data was not available to develop a post-hoc control group,treatment-only billing analyses were
conducted.
For the purposes of this analysis, a household is considered a treatment household if it has received a
program incentive. Additionally, a household is considered a control household if the household has not
received a program incentive.To isolate measure impacts, treatment households are eligible to be
included in the billing analysis if they installed only one measure during the 2024 program year. Isolation
of individual measures is necessary to provide valid measure-level savings. Households that installed
more than one measure may display interactive energy savings effects across multiple measures that
are not feasibly identifiable.Therefore, instances where households installed isolated measures are
used in the billing analyses. In addition,the pre-period identifies the period prior to measure installation
while the post-period refers to the period following measure installation.
The Evaluators utilized propensity score matching (PSM) to match nonparticipants to similar participants
using pre-period billing data. PSM allows the evaluators to find the most similar household based on the
customers' billed consumption trends in the pre-period and verified with statistical difference testing.
After matching based on these variables,the billing data for treatment and control groups are
compared, as detailed in IPMVP Option C.The Evaluators fit regression models to estimate weather-
dependent daily consumption differences between participating customer and nonparticipating
customer households.
2.2.3.3 Cohort Creation
The PSM approach estimates a propensity score for treatment and control customers using a logistic
regression model. A propensity score is a metric that summarizes several dimensions of household
characteristics into a single metric that can be used to group similar households.The Evaluators created
a post-hoc control group by compiling billing data from a subset of nonparticipants in the Avista territory
to compare against treatment households using quasi-experimental methods.This allowed the
Evaluators to select from a large group of similar households that have not installed an incented
measure. With this information, the Evaluators created statistically valid matched control groups for
each measure via seasonal pre-period usage.The Evaluators matched customers in the control group to
customers in the treatment group based on nearest seasonal pre-period usage (e.g., summer,spring,
fall, and winter) and exact 3-digit zip code matching (the first three digits of the five-digit zip code). After
matching,the Evaluators conducted a t-test for each month in the pre-period to help determine the
success of PSM.
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While it is not possible to guarantee the creation of a sufficiently matched control group,this method is
preferred because it is likely to have more meaningful results than a treatment-only analysis. Some
examples of outside variables that a control group can sufficiently control for are changes in economies
and markets, large-scale social changes, or impacts from weather-related anomalies such as flooding or
hurricanes.
After PSM,the Evaluators ran the following regression models:
■ Fixed effect Difference-in-Difference (D-n-D) regression model (recommended in UMP
protocols)'
■ Random effects post-program regression model (PPR) (recommended in UMP protocols)
■ Gross billing analysis (treatment only)
Further details on regression model specifications can be found below.
2.2.3.4 Data Collected
The following lists the data collected for the billing analysis:
1. Monthly billing data for program participants (treatment customers)
2. Monthly billing data for a group of non-program participants (control customers)
3. Program tracking data, including customer identifiers, address, and date of measure installation
4. National Oceanic and Atmospheric Administration (NOAA) weather data between January 1,
2022 and December 31, 2023)
5. Typical Meteorological Year(TMY3) data
Billing and weather data were obtained for program year 2024 (and some of 2025, if available) and for
one year prior to measure install dates(2023).
Weather data was obtained from the nearest weather station with complete data during the analysis
years for each customer by mapping the weather station location with customer zip code.
TMY weather stations were assigned to NOAA weather stations by geocoding the minimum distance
between each set of latitude and longitude points.This data is used for extrapolating savings to long-
run, 30-year average weather.
2.2.3.5 Data Preparation
The following steps were taken to prepare the billing data:
1. Gathered billing data for homes that participated in the program.
2. Excluded participant homes that also participated in the other programs, if either program
disqualifies the combination of any other rebate or participation.
9 National Renewable Energy Laboratory(NREL)Uniform Methods Project(UMP)Chapter 17 Section 4.4.7.
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3. Gathered billing data for similar customers that did not participate in the program in evaluation.
4. Excluded bills missing address information.
5. Removed bills missing fuel type/Unit of Measure (UOM).
6. Removed bills missing usage, billing start date, or billing end date.
7. Remove bills with outlier durations (<9 days or>60 days).
8. Excluded bills with consumption indicated to be outliers.
9. Remove duplicate bills and any bills with overlapping billing periods. If two billing periods
overlapped,the bill with a start date that matched the previous bill's end date was included and
the other bill was excluded. For example, if overlapping bill 1 had a 02/19/2024 start date,
overlapping bill 2 had a 02/25/2024 start date, and the previous bill had a 02/19/2024 end date,
overlapping bill 2 would be removed. If there was no previous bill, the overlapping bill with the
earlier start date was included and the other overlapping bill was removed.
10. Calendarized bills (recalculates billing dates, usage, and total billed days such that bills begin and
end at the start and end of each month).
11. Obtained weather data from nearest NOAA weather station using 5-digit zip code per
household.
12. Computed Heating Degree Days (HDD) and Cooling Degree Days (CDD)for a range of setpoints.
The Evaluators assigned a setpoint of 657 for both HDD and CDD.The Evaluators tested and
selected the optimal temperature base for HDDs and CDDs based on model R-squared values.
13. Removed measure cohorts without at least 75 treatment customers.
14. Selected treatment customers with only one type of measure installation during the analysis
years and combined customer min/max install dates with billing data (to define pre- and post-
periods).
15. Restricted to treatment customers with install dates in specified range (typically January 1, 2024
through June 30, 2024)to allow for sufficient post-period billing data.
16. Restricted to control customers with usage less than or equal to two times the maximum
observed treatment group usage.This has the effect of removing control customers with
incomparable usage relative to the treatment group.
17. Removed customers with incomplete post-period bills (<6 months).
18. Removed customers with incomplete pre-period bills.
19. Restricted control customers to those with usage that was comparable with the treatment
group usage.
20. Created a matched control group using PSM and matching on pre-period seasonal usage and zip
code.
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2.2.3.6 Regression Models
The Evaluators ran the following models for matched treatment and control customers for each
measure with sufficient participation and data availability.The model with the best fit (highest adjusted
R-squared)was selected.The Evaluators utilized Model 3 to estimate energy savings if there was
insufficient non-participant billing data to develop a comparable control group.
Model 1:Fixed Effects Difference-in-Difference Regression Model
The following equation displays the first model specification to estimate the average daily savings due to
the measure.
Equation 2-3:Fixed Effects Difference-in-Difference (D-n-D)Model Specification
sADCit = ao +f31(Post)it +MPost x Treatment)it +f33(HDD)it +f34(CDD)it +
f35(Post x HDD)it +&(Post x CDD)it +f3APost x HDD x Treatment)it +f38(Post x CDD x
Treatment)it +f39(Month)t +f310(Customer Dummy)i + £it
Where,
■ i=the ith household
■ t=the first, second,third, etc. month of the post-treatment period
■ ADCit =Average daily usage reading t for household i during the post-treatment period
■ Postit =A dummy variable indicating pre-or post-period designation during period t
at home i
■ Treatmenti =A dummy variable indicating treatment status of home i
■ HDDit =Average heating degree days (base with optimal Degrees Fahrenheit) during
period t at home i
■ CDDit =Average cooling degree days (base with optimal Degrees Fahrenheit) during period
t at home i (if electric usage)
■ Montht=A set of dummy variables indicating the month during period t
■ Customer Dummyi =a customer-specific dummy variable isolating individual household
effects
■ £it =The error term
■ a0=The model intercept
■ #1_10 = Coefficients determined via regression
The Average Daily Consumption (ADC) is calculated as the total monthly billed usage divided by the
duration of the bill month.f32 represents the average change in daily baseload in the post-period
between the treatment and control group and f37 and f38 represent the change in weather-related daily
consumption in the post-period between the groups.Typical monthly and annual savings were
estimated by extrapolating the f37 and f38 coefficients with either Typical Meteorological Year(TMY) or
current year HDD and CDD data. However, in the case of gas usage, only the coefficient for HDD is
utilized because CDDs were not included in the regression model.
The equation below displays how savings were extrapolated for a full year utilizing the coefficients in the
regression model and TMY data.TMY data is weighted by the number of households assigned to each
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Avista Idaho PY2024
weather station. Depending on TMY data quality and whether the Evaluators hope to identify long-term
average savings trends or specific current year estimates,TMY HDD/CDD or current year HDD/CDD can
be used in savings extrapolation.
Equation 2-4:Savings Extrapolation
Annual Savings = !'2 * 365.25 +fl2 * TMY HDD +Q$ * TMY CDD
Model 2:Random Effects Post-Program Regression Model
The following equation displays the second model specification to estimate the average daily savings
due to the measure. The post-program regression (PPR) model combines both cross-sectional and time
series data in a panel dataset.This model uses only the post-program data,with lagged energy use for
the same calendar month of the pre-program period acting as a control for any small systematic
differences between the treatment and control customers; in particular, energy use in calendar month t
of the post-program period is framed as a function of both the participant variable and energy use in the
same calendar month of the pre-program period.The underlying logic is that systematic differences
between treatment and control customers will be reflected in the differences in their past energy use,
which is highly correlated with their current energy use. These interaction terms allow pre-program
usage to have a different effect on post-program usage in each calendar month.
The model specification is as follows:
Equation 2-5:Post-Program Regression (PPR)Model Specification
ADCit = ao +f31(Treatment)i +F'2 (PreUsageSpring)i +(33(PreUsageSummer)i
+,64(PreUsageFall)i +/35(PreUsageWinter)i + &(Month)t
+,67(Month x PreUsageSpring)it +f38(Month x PreUsageSummer)it
+/39(Month x PreUsageFall)it +#10(Month x PreUsageWinter)it +Q11(HDD)it
+,612(CDD)it +f313(Treatment x HDD)it +f314(Treatment x CDD)it + Eit
Where,
■ i=the ith household
■ t=the first, second,third, etc. month of the post-treatment period
■ ADCit =Average daily usage for reading t for household i during the post-treatment period
■ Treatmenti =A dummy variable indicating treatment status of home i
■ Montht = Dummy variable indicating month of month t
■ PreUsageSpringi =Average daily usage in the spring months across household is available
pre-treatment billing reads
■ PreUsageSummeri =Average daily usage in the summer months across household is
available pretreatment billing reads
■ PreUsageFalli =Average daily usage in the fall months across household is available
pretreatment billing reads
■ PreUsageWinteri =Average daily usage in the winter months across household is
available pre-treatment billing reads
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Avista Idaho PY2024
■ HDDit =Average heating degree days (base with optimal Degrees Fahrenheit) during
period t at home i
■ CDDit =Average cooling degree days (base with optimal Degrees Fahrenheit) during period
t at home i(if electric usage)
■ £it = Customer-level random error
■ ao=The model intercept for home i
■ F'1-14 = Coefficients determined via regression
The coefficient f31 represents the average change in consumption between the pre-period and post-
period for the treatment group and!'13 and f314 represent the change in weather-related daily
consumption in the post-period between the groups.Typical monthly and annual savings were
estimated by extrapolating the F'13 and f314 coefficients with either Typical Meteorological Year(TMY) or
current year HDD and CDD data.
The equation below displays how savings were extrapolated for a full year utilizing the coefficients in the
regression model and TMY data. As detailed above, either TMY or current year HDD/CDD data can be
used for extrapolation depending on whether the evaluators are interested in long-term savings trends
or year-specific savings estimates.
Equation 2-6:Savings Extrapolation
Annual Savings = f31 * 365.25 +f311 * TMY HDD +f312 * TMY CDD
Model 3:Gross Billing Analysis, Treatment-Only Regression Model
The sections above detail the Evaluator's methodology for estimating net energy savings for each
measure.The results from the above methodology report net savings due to the inclusion of the
counterfactual comparison group. However, if sufficient non-participant data is not available to develop
a valid control group, gross savings can also be calculated via a treatment-only regression.This analysis
does not include control group billing data and therefore models energy reductions between the pre-
period and post-period for the measure participants (treatment customers).
To calculate the impacts of each measure, the Evaluators applied linear fixed effects regression using
participant billing data with weather controls in the form of Heating Degree Days (HDD) and Cooling
Degree Days(CDD).The following equation displays the model specification to estimate the average
daily savings due to the measure.
Equation 2-7: Treatment-Only Fixed Effects Weather Model Specification
ADCit = ao +,g1(Post)it +f32(HDD)it +f33(CDD)it +f34(Post x HDD)it +f3s(Post x CDD)it
+&(Customer Dummy)i +f32(Month)t + -it
Where,
■ i=the ith household
■ t=the first, second,third, etc. month of the post-treatment period
■ ADCit =Average daily usage for reading t for household i during the post-treatment period
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Avista Idaho PY2024
■ HDDIt = Average heating degree days (base with optimal Degrees Fahrenheit) during
period t at home i
■ CDDIt =Average cooling degree days (base with optimal Degrees Fahrenheit) during period t
at home i(if electric usage)
■ Postlt = A dummy variable indicating pre- or post-period designation during period t at
home i
■ Customer Dummyl = a customer-specific dummy variable isolating individual household
effects
■ Montht = Dummy variable indicating month of month t
■ Eit = Customer-level random error
■ ao=The model intercept for home i
■ al-7 = Coefficients determined via regression
The results of the treatment-only regression models are gross savings estimates. If billing data for
statistically comparable control customers (i.e., non-participant Avista customers with comparable
usage to treatment customers) is not available, such gross savings analyses can provide reliable savings
estimates.The gas furnace billing analysis was run as a treatment-only regression and current year(i.e.,
2024) HDD data was used to extrapolate savings. While treatment-only models may not separate out
the effects of national or regional events like a pandemic or recession,they still provide meaningful
estimates of changes in energy usage associated with measure installation. Given that the COVID-19
pandemic is unlikely to dramatically affect customer energy usage as of PY2024,treatment-only models
can provide valid estimates of the savings associated with many energy efficiency measures.
2.2.3.7 Billing Heating Load Estimation
In addition to the regression based IPMVP Option C billing analysis, the Evaluators often employ a
heating load estimation billing analysis. Heating load estimation is a prime methodology for estimating
savings associated with space heating measures such as boilers.This methodology follows IPMVP Option
A, in which the estimation of a key parameter is used to calculate savings.The heating load estimation
methodology follows the same data collection and data preparation steps outlined in Section 2.2.3.4
and Section 2.2.3.5, respectively. However, instead of ending with a regression analysis, post-period
billing data are used to estimate customer heating load, which is used as an input in a deemed savings
formula to calculate energy savings.
The first step in heating load estimation is calculating TMY3 weather normalized average daily
consumption.To do so, customer-specific regressions are run to determine the effect of daily HDD on
average daily consumption.This is a straightforward regression of the form:
Equation 2-8:Heating Load Regression
ADCL = ao +flj(HDD)i
Where,
■ i=the ith household
■ ADCj =Average daily usage for household i during the post-treatment period
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Avista Idaho PY2024
■ HDDL =Average heating degree days (base with optimal Degrees Fahrenheit) at home i
■ N1 = Coefficient determined via regression
This regression is run separately for each customer to determine f'1, impact of HDD on average daily
consumption (i.e.,the change in Therms usage per HDD). From there,/31 multiplied by HDD is subtracted
from ADC and fl1multiplied by TMY3_HDD is added back to ADC to calculate TMY3 weather normalized
average daily consumption.The actual HDD attributable therms usage is subtracted from average daily
consumption and the TMY_HDD attributable therms are added back in, as outlined in the following
equation.
Equation 2-9: Normalized Average Daily Consumption
NADCL = ADCL —!'1 * (HDD)i + f'1 * (TMY_HDD)i
Where,
■ i=the ith household
■ NADCL = TMY normalized average daily usage for household i during the post-treatment
period
■ f31 = Customer-specific Therms usage per HDD
■ ADCL =Average daily usage for household i during the post-treatment period
■ HDDL =Average heating degree days (base with optimal Degrees Fahrenheit) at home i
■ TMY_HDDL =Average TMY heating degree days at home i
Once TMY normalized average daily usage is calculated, the penultimate step to heat load estimation is
calculating customer baseload usage. Customer baseload usage represents the energy customers use for
non-heating needs, such as a gas stove or dryer. For gas heating measures, customer baseload usage can
be calculated as the average NADC across June,July, and August. Customer-specific baseload usage is
then subtracted from NADC and to determine customer daily heating load.
Customer heating loads are then used in the following deemed savings equation to calculate the annual
savings associated with gas furnace installation.
Equation 2-10: Gas Furnace Savings
1 1
Savingsi = 365 * HLL * ( — )
Basei Ef fl
Where,
■ i=the ith household
■ Savingsl = Annual Therms savings for household i based on post-treatment period billing
data
■ 365 = Days in the year
■ HLj = Customer-specific daily heating load for household i
■ Basel = Baseline furnace efficiency at home i, which is assumed to be 85.5% per the RTF Gas
Furnace LIES Measurelo
10 https:Hrtf.nwcouncil.org/measure/residential-gas-furnaces/
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Avista Idaho PY2024
■ Ef fl = Installed furnace efficiency at home i, which is assumed to be 95%
2.2.4 Net-To-Gross
The Northwest RTF LIES measures do not require NTG adjustments as they are built into the deemed
savings estimates. In addition, billing analyses with counterfactual control groups, as proposed in our
impact methodology, does not require a NTG adjustment, as the counterfactual represents the
efficiency level at current market (i.e. the efficiency level the customer would have installed had they
not participated in the program). For treatment-only furnace savings calculations,the evaluators utilized
a net-to-gross ratio of 1 based on the assumption that free ridership, spillover, and market effects for
the ID gas furnace program were minimal.The Evaluators removed any customers participating in
multiple energy efficiency programs prior to conducting the furnace billing analysis meaning spillover is
unlikely. Furthermore, given that Idaho ended its COVID-19 public health emergency declaration on
April 15, 2022, COVID-19 is unlikely to have affected 2024 furnace savings calculations.11 Lastly,the only
extreme weather event Idaho experience in 2023 and 2024 was a drought and heat wave,which unlike a
blizzard, is unlikely to dramatically affect gas heating energy usage."
ii https:Hgov.idaho.gov/pressreIease/public-health-disaster-emergency-declaration-to-end-april-15/
iz https://www.ncei.noaa.gov/access/billions/state-summary/ID
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Avista Idaho PY2024
3. Residential Impact Evaluation Results
The Evaluators completed an impact evaluation on Avista's Residential portfolio to verify program-level
and measure-level energy savings for PY2024. The following sections summarize findings for each
natural gas impact evaluation in the Residential Portfolio in the Idaho service territory.The Evaluators
used data collected and reported in the tracking database, online application forms, Avista TRM, RTF,
and billing analysis of participants and nonparticipants to evaluate savings.This approach provided the
strongest estimate of achieved savings practical for each program,given its delivery method, magnitude
of savings, number of participants, and availability of data.Table 3-1 summarizes the Residential verified
impact savings by program.
Table 3-1:Residential Verified Impact Savings by Program
Program Expected Savings Verified Savings Verified Realization
(Therms) (Therms) Rate
Shell 18,414.11 21,429.50 116.38%
Fuel Efficiency 0 0 -
ENERGY STAR Homes 0 0 -
Appliances 11,973.57 19,967.99 166.77%
Midstream 51,706.71 144,314.62 279.10%
Home Energy Audit 0 NA NA
On Bill Repayment 0 NA NA
Total Res 82,094.39 185,712.11 226.22%
In PY2024,Avista completed and provided incentives for residential natural gas measures in Idaho and
reported total natural gas savings of 82,094.39 Therms, with verified savings of 185,712.11 therms,
leading to an overall achievement of 226.22%of the expected savings for the residential programs.
Further details of the impact evaluation results by program are provided in the sections following.
3.1 Simple Verification Results
In PY2023,the Evaluators surveyed 2,229 unique customers that participated in Avista's residential
energy efficiency program in the fall of 2023 using an email survey approach. The Evaluators did not
complete surveying efforts in the PY2024 evaluation and therefore referenced simple verification
responses from the PY2023 impact evaluation.
The Evaluators surveyed customers that received rebates for HVAC, Water Heater, Shell, Small Home&
MF Weatherization, and Appliance Programs in PY2023. For the purposes of this report,the results for
the Appliance Program are summarized.
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Table 3-2:Summary of Survey Response Rate
Population Respondents
Initial email contact list 8,262
Invalid or bounced 416
Invalid or bounced email(%) 5.0%
Invitations sent(unique valid) 7,846
Completions 2,229
Response rate(%) 28.4%
3.1.1 In-Service Rates
The Evaluators calculated in-service rates of installed measures from simple verification surveys
deployed to program participants. The Fuel Efficiency program was surveyed for electric measures; the
sample is provided in the Idaho Electric Impact Evaluation report and does not contribute to the
precision for the Idaho Gas impacts. The Evaluators asked participants if the rebated equipment is
currently installed and working, in addition to questions about the new equipment fuel type. The
Evaluators achieved ±13.91% precision across the programs surveyed for the natural gas measures in
Avista's Idaho service territory, summarized in Table 3-3. When summarizing Idaho and Washington in-
service rates,the Evaluators achieved ±9.6% precision across the programs, summarized in Table 3-4.
Table 3-3:State-Level Simple Verification Precision by Program
IProgram Population Respondents •0' cl
Residential Appliances 115 27 90%±13.91%
Table 3-4:Mixed State-Level Simple Verification Precision by Program
Program Population Respondents Precision at 90%Cl
Residential Appliances 115 43 90%±9.6%
The measure-level ISRs determined from the verification survey for each program in which simple
verification was conducted is presented in the tables below.The tables below summarize Idaho-level
(state-level) respondents and ISR as well as Idaho and Washington-level (mixed state-level) respondents
and ISR.
Table 3-5:Appliances Program ISRs by Measure
Measure State-level level level State- ISR State- Mixed State- Mixed
Methodology
Respondents
ISR Respondents
ISR
G Energy Star Rated Clothes Dryer 6 100% 10 100% Mixed state ISR
G Energy Star Rated Front Load Washer 14 100% 29 100% Mixed state ISR
G Energy Star Rated Top Load Washer 7 86% 21 95% Mixed state ISR
These ISR values were utilized in the desk reviews for the Appliance Programs in order to calculate
verified savings. Additional insights from the survey responses are summarized in Appendix A: Summary
of Survey Respondents.
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Avista Idaho PY2024
3.2 Program-Level Impact Evaluation Results
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Residential sector in the section below.
3.2.1 Shell Program
The Shell Program provides incentives to customers for improving the integrity of the home envelope
with upgrades to windows and storm windows. Rebates are issued after the measure has been installed
for insulation and window measures. Participating homes must have natural gas or natural gas heating
and itemized invoices including measure details such as insulation levels, window values, and square
footage. In order to be eligible for incentive,the single-family households, including fourplex or less,
must demonstrate an annual electricity usage of at least 8,000 kWh or an annual gas usage of at least
340 Therms. Multifamily homes have no usage requirement.This program includes free manufactured
home duct sealing implemented by UCONS.Table 3-6 summarizes the measures offered under this
program.
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Avista Idaho PY2024
Table 3-6:Shell Program Measures
Impact Analysis
Measure Description Methodology
G Attic Insulation With Natural Gas Attic insulation for homes heated with natural gas RTF UES
Heat
G Energy Star Certified Insulated Energy Star door replacement for homes heated RTF UES
Door with natural gas
G Floor Insulation With Natural Gas Floor insulation for homes heated with natural gas RTF UES
Heat
G Sliding Glass Doors DIY with High-efficiency sliding glass door replacement for
Natural Gas Heat homes heated with natural gas-installed by the RTF UES
homeowner
G Sliding Glass Doors with Natural High-efficiency sliding glass door replacement for
Gas Heat
homes heated with natural gas-installed by a RTF UES
contractor
G Storm Windows with Natural Gas High-efficiency storm window replacement for RTF UES
Heat homes heated with natural gas J
G Wall Insulation With Natural Gas Wall insulation for homes heated with natural gas RTF UES
Heat
G Windows DIY Replc With Natural High-efficiency window replacement for homes
Gas Heat heated with natural gas-installed by the RTF UES
homeowner
G Window Replc With Natural Gas High-efficiency window replacement for homes RTF UES
Heat heated with natural gas-installed by a contractor
G Multifamily Attic Insulation With Attic insulation for homes heated with natural gas RTF UES
Natural Gas Heat
G Multifamily Energy Star Certified Energy Star door replacement for homes heated RTF UES
Insulated Door with natural gas
G Multifamily Floor Insulation With Floor insulation for homes heated with natural gas RTF UES
Natural Gas Heat
G Multifamily Sliding Glass Doors High-efficiency sliding glass door replacement for
DIY with Natural Gas Heat homes heated with natural gas-installed by the RTF UES
_ homeowner
G Multifamily Sliding Glass Doors High-efficiency sliding glass door replacement for
with Natural Gas Heat homes heated with natural gas-installed by a RTF UES
contractor
G Multifamily Storm Windows with High-efficiency storm window replacement for RTF UES
Natural Gas Heat homes heated with natural gas
G Multifamily Wall Insulation With Wall insulation for homes heated with natural gas RTF UES
Natural Gas Heat
G Multifamily Window DIY Replc High-efficiency window replacement for homes
With Natural Gas Heat heated with natural gas-installed by the RTF UES
homeowner
G Multifamily Window Replc With High-efficiency window replacement for homes RTF UES
Natural Gas Heat heated with natural gas-installed by a contractor
The following table summarizes the adjusted and verified natural gas savings for the Shell Program
impact evaluation.
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Avista Idaho PY2024
Table 3-7.Shell Program Verified Natural Gas Savings
PY2024 Expected Adjusted Verified Verified
Measure Participation Savings Savings Savings Realization
(Therms) (Therms) (Therms) Rate
G Attic Insulation With Natural Gas 40 2,555.28 2,601.84 2,442.99 95.61%
Heat
G Energy Star Certified Insulated 31 133.35 152.41 152.41 114.29%
Door
G Floor Insulation With Natural Gas 7 145.12 145.12 314.47 216.70%
Heat
G Sliding Glass Doors DIY with o
Natural Gas Heat 5 116.90 116.90 109.18 93.39/
G Sliding Glass Doors with Natural 82 1,686.70 1,499.29 1,545.83 91.65%
Gas Heat
G Wall Insulation With Natural Gas 11 440.00 410.33 609.09 138.43%
Heat
G Window DIY Replc With Natural 25 764.67 681.59 557.76 72.94%
Gas Heat
G Window Replc With Natural Gas 310 12,484.49 14,970.12 15,173.61 121.54%
Heat
G Multifamily Attic Insulation With 0 0.00 0.00 0.00 0.00/
Natural Gas Heat
G Multifamily Energy Star Certified 0 0.00 0.00 0.00 0.00/
Insulated Door
G Multifamily Floor Insulation With 1 21.36 3.72 10.63 49.77%
Natural Gas Heat
G Multifamily Sliding Glass Doors 1 16.70 16.70 12.13 72.62%
DIY with Natural Gas Heat
G Multifamily Sliding Glass Doors
2 33.40 33.40 6.89 20.62%
with Natural Gas Heat
G Multifamily Wall Insulation With 1 13.02 9.30 24.33 186.88%
Natural Gas Heat
G Multifamily Window DIY Replc o
With Natural Gas Heat 0 0.00 0.00 0.00 0.00/G Multifamily Window Replc With o
Natural Gas Heat 4 3.12 81.90 470.18 15,069.75/0
Total 520 18,414.11 20,722.62 21,429.50 116.38%
The Shell Program displayed verified savings of 21,429.50 Therms with a realization rate of 116.38%
against the expected savings for the program.The following table summarizes the incentive costs
associated with the program.
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Avista Idaho PY2024
Table 3-8:Shell Program Costs
Measure Incentive Costs
G Attic Insulation With Natural Gas Heat $31,941.00
G Energy Star Certified Insulated Door $3,800.00
G Floor Insulation With Natural Gas Heat $5,442.00
G Sliding Glass Doors DIY with Natural Gas Heat $1,680.00
G Sliding Glass Doors with Natural Gas Heat $47,880.00
G Wall Insulation With Natural Gas Heat $6,600.00
G Window DIY Replc With Natural Gas Heat $10,184.18
G Window Replc With Natural Gas Heat $318,531.88
G Multifamily Attic Insulation With Natural Gas Heat $0.00
G Multifamily Energy Star Certified Insulated Door $0.00
G Multifamily Floor Insulation With Natural Gas Heat $267.00
G Multifamily Sliding Glass Doors DIY with Natural Gas Heat $240.00
G Multifamily Sliding Glass Doors with Natural Gas Heat $960.00
G Multifamily Wall Insulation With Natural Gas Heat $139.50
G Multifamily Window DIY Replc With Natural Gas Heat $0.00
G Multifamily Window Replc With Natural Gas Heat $2,340.00
Total $430,005.56
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Shell Program in the section below.
3.2.1.1 Database Review& Verification
The following sections describe the Evaluator's database review and document verification findings for
the Shell Program.
3.2.1.2 Database Review& Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Shell
Program.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Section 2.2.2.3.
For each sampled measure, the Evaluators reviewed the number of units installed, square footage, and
other key equipment characteristics such as insulation R-value.
The Evaluators identified two sampled Energy Star Door measures for which the ex-ante estimated
savings were lower than the savings values included in the Avista TRM. One of these two instances
appeared to be due to ex-ante savings accounting for a lower door quantity than was actually installed
per tracking data.These ex-ante savings underestimations contributed to a 114% realization rate for
Energy Star certified insulated doors as shown in Table 3-7.
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Avista Idaho PY2024
3.2.1.3 Verification Surveys
The Evaluators conducted verification surveys of the residential Shell Program in PY2023. Based on the
results of these surveys and the historically high in-service rates of weatherization programs, the
Evaluators applied 100%in-service rates to all PY2024 Shell measures.
3.2.1.4 Impact Analysis
This section summarizes the savings results for the Shell Program. The Evaluators calculated adjusted
savings for each measure using the active Avista TRM values and verified tracking data. The Evaluators
calculated verified savings for the natural gas measures using the RTF UES values.The Evaluators
conducted a billing analysis for measures where participation allowed. However,the billing analysis
results were not used due to issues with statistical significance and unexpectedly low savings values.
Therefore,the RTF UES values were applied to a random sample of participants, with verification of
project documents such as rebate applications to verify installation, quantity, and efficiency of the
equipment.
3.2.1.5 Verified Savings
The Shell Program in total displayed a realization rate of 116.38%with 21,429.50 therms verified natural
gas savings in the Idaho service territory, as displayed in Table 3-7.The realization rate for the gas
savings in the Shell Program deviates from 100%due primarily to the differences between the
categories applied in the Avista TRM prescriptive savings values and the more detailed categories
present with unique RTF UES values associated with heating type and climate zone. In addition, missing
verified R-values, square footage, and quantity of units from sampled projects led to variation in
realization rate for each measure type.
The G Multifamily Window Replc With Natural Gas Heat measure had an extremely inflated realization
rate (close to 15,070%) due to the fact that ex-ante savings were primarily electric for all four PY2024
participants.The ex-ante savings estimates appeared to assume electric space heating,while the
Evaluators' document review process verified that all four participants had gas furnace space heating.
This discrepancy in assumed space heating fuel type was the main factor that contributed to the
extremely high realization rate for this measure.
The G Window Replc With Natural Gas Heat measure realization rate deviated from 100% because there
were discrepancies in the documentation provided in terms of square footage and unit quantity
verification. Many rebate forms only provided window type and the price. Square footage of the
window area as well as the quantity of windows are essential inputs to calculate savings using the RTF
UES workbook, so the Evaluators were forced to make assumptions to impute such missing data.
The lack of granularity in the Avista TRM and misalignment with average participant characteristics led
to a low realization rate for attic insulation and window measures. The Evaluators recommend Avista
update the Avista TRM value to reflect an accurate weighted average of participation home
characteristics or apply different savings values based on customer heating zone (as is the case in the
RTF UES workbooks).
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Avista Idaho PY2024
3.2.2 ENERGY STAR° Homes Program
The ENERGY STAR® Homes Program provides rebates for manufactured homes within Avista's service
territory that attain an ENERGY STAR® certification.This program is incentivized for ENERGY STAR' Eco-
rated homes.Table 3-9 summarizes the measures offered under this program.
Table 3-9:ENERGY STAR®Homes Program MeasureMeasure Description Impact Analysis
Methodology
E ENERGY STAR Home- Manufactured, ENERGY STAR-rated manufactured RTF UES
Gas&Electric home with gas and electric
The Energy Star Homes Program did not have any natural gas projects rebated in the Idaho Service
Territory in PY2024.
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Avista Idaho PY2024
3.2.3 Fuel Efficiency Program
The Residential Fuel Efficiency Program encourages customers to consider converting their resistive
electric space and water heating equipment to natural gas.This program is offered to residential
customers in the Idaho service territory. Customers must use Avista electricity for electric straight-
resistance heating or water heating to qualify for the rebate,which is verified by evaluating their energy
use.The home's electric baseboard or furnace heat consumption must have been at least 8,000 kWh
during the previous heating season. Customers receive incentives after installation and after submitting
a completed rebate form.Table 3-10 summarizes the measures offered under this program.
Table 3-10: Fuel Efficiency Program Measures
Measure I Description I Impact Analysis Methodology
E Electric To Natural Gas Furnace Electric baseboard or forced air furnace Avista TRM
heat to natural gas forced air furnace
E Electric To Natural Gas Furnace& Electric to natural gas furnace and water
Avista TRM
Water Heat heat combo
The program does not contain any natural gas saving measures; however,the program includes a
therms penalty due to converting electric equipment to natural gas equipment.The verified therms
penalty is 5,620 therms and represents an 89.19% realization rate against the expected therms penalty
amount of 6,301.The following table displays the therms penalty by measure.
Table 3-11:Fuel Efficiency Program Verified Natural Gas Penalty
PY2023 Expected Adjusted Verified Verified
Measure Participation � Penalty I Penalty Penalty Realization
(Therms) (Therms) (Therms) Rate
E Electric To Natural Gas Furnace 11 -4,041 -4,939 -4,490 111.11%
E Electric To Natural Gas Furnace&
4 -2,260 -2,260 -1,130 50.00%
Water Heat
Total 15 -6,301 -7,199 -5,620 89.19%
The therms penalties represented in the table above are not aggregated in the Residential portfolio
impact evaluation and are summarized here for planning purposes.The costs associated with this
program are claimed in the Idaho Electric Impact Evaluation Report.The Evaluators summarize the
program-specific and measure-specific impact analysis activities, results, conclusions, and
recommendations for the Fuel Efficiency Program in Idaho Electric Impact Evaluation Report for PY2024.
Evaluation and Measurement Report 32

Avista Idaho PY2024
3.2.4 Appliances Program
The Appliances Program is a residential prescriptive program that offers incentives for customers to
upgrade their existing clothes washers and dryers to ENERGY STAR-rated clothes dryers and washers.
Primary multifamily homes with shared interior walls including apartments, duplexes, townhomes, and
condos have no minimum usage requirement to be eligible for this program. However, Avista defines
seasonal and recreational homes as ineligible.
This section summarizes the impact results of the Appliances Program evaluation.Table 3-12
summarizes the measures offered under this program.
Table 3-12:Appliances Program Measures
impact Analysis
=- -
G Energy Star Rated Clothes Dryer ENERGY STAR-certified clothes dryer for RTF UES
residential homes
G Energy Star Rated Front Load ENERGY STAR-certified front-loading clothes RTF UES
Washer washer for residential homes
G Energy Star Rated Front Load ENERGY STAR-certified top loading clothes RTF UES
Washer washer for residential homes
G Smart Thermostat DIY with Natural ENERGY STAR-certified Smart Thermostat with RTF UES
Gas Heat DIY install for residential homes
G Smart Thermostat Paid Install with ENERGY STAR-certified Smart Thermostat with RTF UES
Natural Gas Heat Paid Install for residential homes
G Multifamily Energy Star Rated ENERGY STAR-certified clothes dryer for RTF UES
Clothes Dryer residential MF homes
G Multifamily Energy Star Rated Front ENERGY STAR-certified front-loading clothes RTF UES
Load Washer washer for residential MF homes
G Multifamily Energy Star Rated Top ENERGY STAR-certified top loading clothes RTF UES
Load Washer washer for residential MF homes
G Multifamily Smart Thermostat DIY ENERGY STAR-certified Smart Thermostat with RTF UES
with Natural Gas Heat DIY install for residential MF homes
G Multifamily Smart Thermostat Paid ENERGY STAR-certified Smart Thermostat with RTF UES
Install with Natural Gas Heat Paid Install for residential MF homes
The following table summarizes the verified natural gas savings for the Appliances Program impact
evaluation.
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Avista Idaho PY2024
Table 3-13:Appliances Program Verified Natural Gas Savings
PY2024 Expected Adjusted Verified Verified
Measure Participation Savings Savings Savings Realization
(Therms) (Therms) (Therms) Rate
G Energy Star Rated Clothes Dryer 16 40.80 40.80 24.00 58.82%
G Energy Star Rated Front Load Washer 64 385.92 385.92 153.60 39.80%
G Energy Star Rated Top Load Washer 10 54.27 0.00 0.00 0%
G Smart Thermostat DIY with Natural 153 4,219.86 4,219.86 7,283.96 172.61%
Gas Heat
G Smart Thermostat Paid Install with 252 6,899.76 6,899.76 11,865.07 171.96%
Natural Gas Heat
G Multifamily Energy Star Rated Clothes 0 0.00 0.00 0.00 0%
Dryer
G Multifamily Energy Star Rated Front 0 0.00 0.00 0.00 0%
Load Washer
G Multifamily Energy Star Rated Top o
Load Washer 0 0.00 0.00 0.00 0/
G Multifamily Smart Thermostat DIY 5 133.20 133.20 229.06 171.97%
with Natural Gas Heat
G Multifamily Smart Thermostat Paid
Install with Natural Gas Heat 9 239.76 119.88 412.30 171.96/0
Total 509 11,973.57 11,799.42 19,967.99 166.77%
The Appliances Program displayed verified savings of 19,967.99 Therms with a realization rate of
166.77%against the expected savings for the program.The following table summarizes the incentive
costs associated with the program.
Table 3-14:Appliances Program Costs
Measure ncentive Costs
G Energy Star Rated Clothes Dryer $750.00
G Energy Star Rated Front Load Washer $3,200.00
G Energy Star Rated Top Load Washer $450.00
G Smart Thermostat DIY with Natural Gas Heat $18,270.99
G Smart Thermostat Paid Install with Natural Gas Heat $38,719.35
G Multifamily Energy Star Rated Clothes Dryer $0.00
G Multifamily Energy Star Rated Front Load Washer $0.00
G Multifamily Energy Star Rated Top Load Washer $0.00
G Multifamily Smart Thermostat DIY with Natural Gas Heat $599.99
G Multifamily Smart Thermostat Paid Install with Natural Gas Heat $1,350.00
Total $63,340.33
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Appliance Program in the section below.
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Avista Idaho PY2024
3.2.4.1 Database Review& Verification
The following sections describe the Evaluator's database review and document verification findings for
the Appliances Program.
3.2.4.2 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Appliances
Program.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Section 2.2.2.3.
The Evaluators found all Appliances Program rebates to have project documentation with the associated
model number and efficiency values in either web rebate data or mail-in rebate applications. In
addition, documents included AHRI certifications or model numbers necessary to verify AHRI
certifications.This allowed Evaluators to easily verify model specifications and apply savings.
The Evaluators found six Smart Thermostat projects that did not qualify based on Energy Star
Requirements.The Evaluators assigned 0 therms savings to these projects accordingly.
3.2.4.3 Verification Surveys
In PY2023,the Evaluators randomly selected a subset of participant customers to survey for simple
verification of installed measures as described in Section 2.2.2.4.The Evaluators included questions such
as:
■ What type of clothes washer/dryer did this clothes washer/dryer replace?
■ Is your home's water heated with electricity, natural gas, or another fuel?
■ Was the previous equipment functional?
■ Is the newly installed equipment still properly functioning?
The responses to this verification survey conducted in PY2023 were used to calculate ISRs for the
measures offered in the Appliance Program in PY2024. In addition,the Evaluators asked participants
how the COVID19 pandemic stay-at-home orders have affected their household's energy consumption.
The responses to these additional questions can be found in Appendix A.
Table 3-15 displays the ISRs for each of the Appliances Program measures for Idaho and Washington
natural gas territory combined, as the Idaho-only territory responses did not meet 90/10 precision goals.
The ISRs resulted in ±9.6% precision at the 90%confidence interval for the program.
Table 3-15:Appliances Verification Survey ISR Results
Number Number of Precision at In-Service
Measure of Survey 90% Rate
Rebates* Completes Confidence
G Energy Star Rated Clothes Dryer 40 10 100%*
G Energy Star Rated Top Load Washer 143 21 90%±9.55% 95%*
G Energy Star Rated Front Load Washer 126 29 100%*
*This count includes Idaho and Washington rebates
Survey respondents described equipment to be currently functioning, leading to a 95-100% ISR for all
measures.The Evaluators applied the ISRs listed in Table 3-15 to each rebate to quantify verified savings
for each measure.
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Avista Idaho PY2024
3.2.4.4 Impact Analysis
This section summarizes the verified savings results for the Appliances Program.The Evaluators
calculated verified savings for the remaining measures using active values from the Avista TRM
workbook.These values were applied to a random sample of participants, with verification of project
documents such as rebate applications to verify installation, quantity, and efficiency of the equipment.
3.2.4.5 Billing Analysis
The results of the billing analysis for the Appliances Program are provided in this section. The
methodology for the billing analysis is provided in Section 2.2.3.2.Table 3-16 displays customer counts
for customers considered for billing analysis (i.e. customer with single-measure installations) and
identifies measures that met the requirements for a billing analysis.The customers considered for
Energy Star Rated Front Load Washer and Smart Thermostat with Natural Gas Heat billing analyses
include customers in both Washington and Idaho service territories to gather the maximum number of
customers possible for precise savings estimates.
Table 3-16:Measures Considered for Billing Analysis,Appliances Program
Isolated-MeasureMeasure Number of Sufficient
Measure Considered for Customers w/ Participation
Billing Analysis
Installations* Analysis
G Energy Star Rated Front Load Washer ✓ 141* ✓
G Smart Thermostat with Natural Gas Heat ✓ 1,083* ✓
*This count includes rebates from Washington and Idaho
The final number of customers in each treatment and control group are listed in Table 3-17.
The Evaluators performed three tests to determine the success of PSM:
1. t-test on pre-period usage by month
2. Joint chi-square test to determine if any covariates are imbalanced
3. Standardized difference test for each covariate employed in matching
All tests confirmed that PSM performed well for each measure and the Evaluators conducted a linear
regression using the matched participant and nonparticipant monthly billing data.
Table 3-17 provides annual savings per customer for the G Smart Thermostat with Natural Gas Heat
measure, including both single family and multifamily homes.The regression results for the G Energy
Star Rated Front Load Washer measure were not statistically significant,therefore measure savings
were not included. Model 2 (PPR) was selected as the final model for the Appliance Program as it
provided the highest adjusted R-squared among the regression models. Savings are statistically
significant at the 90% level and the adjusted R-squared shows the model provided an excellent fit for the
data (adjusted R-squared >_0.90).
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Avista Idaho PY2024
Table 3-17.Measure Savings,Appliances Program
Annual
Treatment Control Savings 90% •0' Adjusted
UpperMeasure Customers Customers per Lower
ClCustomer
(Therms) I
G Smart Thermostat with Model
Natural Gas Heat 536 2,550 46 42 50 0.92 2. PPR
The Evaluators found the G Smart Thermostat with Natural Gas Heat measure displayed a statistically
significant verified savings value of 46 Therms per year.The Evaluators applied these estimated savings
for single family and multifamily natural gas smart thermostat measures rebated through the program.
3.2.4.6 Verified Savings
The Appliances Program in total displays a verified savings of 19,967.99 Therms with a realization rate of
166.77% in the Idaho service territory, as displayed in Table 3-13.
The realization rate for the natural gas savings in the Appliances Program deviates from 100%due to the
removal of savings from the Top Load Washer measure and the inflated savings from Energy Star Rated
Clothes Dryer measure.The expected savings utilized a 2.72 therms savings value for clothes dryers, but
the appropriate RTF UES value is 9.59 therms.The Evaluators recommend Avista update the clothes
dryer measure to be aligned with the RTF UES value.
The Evaluators recommend Avista update the clothes washer Avista TRM value to correctly assign 1.60
therms savings for the measure, as reflected in the RTF. Currently,the Avista TRM reflects 2.72
therms/unit.Additionally,The Evaluators recommend Avista update the front load clothes washer
Avista TRM value to correctly convert 119.99 kWh/unit to 2.40 therms/unit. Currently,the Avista TRM
reflects 6.03 therms/unit.The combination of these adjustments contributed to the downward
adjustment to verified savings for the program.
The Evaluators found that about 96%of the PY2024 expected savings were attributed to Smart
Thermostat measures in the ID Appliances program.The Evaluators conducted a billing analysis for this
measure, combining single family and multifamily participants to ensure a robust sample.The Evaluators
verified statistically significant savings for this measure at 46 therms per unit.This savings value was
applied to the population of smart thermostat rebates, which drove the realization rate to 172% For the
program, compared to the claimed savings value of 26.64 therms per unit from the Avista TRM.
The Evaluators also found one sampled smart thermostat model that did not meet the minimum RTF
qualifications for savings, although Avista had assigned the maximum savings value to that project.The
Evaluators recommend Avista verify each smart thermostat model meets the RTF requirements for
regional savings compared to the market practice baseline or provide a list of qualified products for
customers to select when participating in this program.
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Avista Idaho PY2024
3.2.5 Midstream Program
Avista converted several residential and nonresidential measures from a downstream delivery channel
to a midstream delivery channel via local distributors. As Avista notes, midstream approaches have
proven successful in other parts of the Pacific Northwest, as well as nationally.The Midstream Program
currently offers midstream incentives to residential customers for measures such as:
Residential natural gas furnaces
Residential natural gas boilers
Residential natural gas storage tank water heaters
Residential natural gas tankless water heaters
The nonresidential midstream measures and impact evaluation results are presented in Section 3.2.5.
This change in delivery channel is seen to expand the benefits gained from the consumer with respect to
the midstream incentive design rather than the downstream incentive design, as well as how customers
use this offering.
This section summarizes the estimated savings Avista has calculated for the Midstream Program. The
Evaluators conducted the first impact evaluation for the measures in this program for PY2024.Table
3-18 summarizes the measures offered under this program.
Table 3-18:Midstream Program Measures
Impact
Methodology—Ad
G Natural Gas Furnace High efficiency natural gas furnace Treatment-only Billing
installation Analysis
G Natural Gas Boiler High efficiency natural gas boiler installation RTF UES
G Natural Gas Storage Tank Water High efficiency natural gas water heater RTF UES
Heater installation
G Natural Gas Tankless Water High efficiency natural gas water heater RTF UES
Heater installation
Sufficient Avista customers purchased a natural gas furnace in 2024 for the Evaluators to calculate
verified natural gas savings via a billing analysis.This billing analysis found that furnace installation in
2024 was associated with annual gas savings of—90.0 therms per household.
The following table summarizes the estimated electric energy savings for the Midstream Program
impact evaluation.
Table 3-19:Midstream Program Verified Natural Gas Savings
Expected AdjustelTr !Verified Realization
� � Units Savings Savings Savings Rate
(Therms) (Therms) (Therms)
G Natural Gas Furnace 1,548 46,731.65 47,870.32 139,326.10 298.14%
G Natural Gas Boiler 2 403.90 404.06 404.06 100.04%
G Natural Gas Storage Tank Water Heater 1 15.12 25.41 25.41 167.98%
G Natural Gas Tankless Water Heater 89 4,556.03 4,559.05 4,559.05 100.07%
Total 1,640 51,706.71 52,858.84 144,314.62 279.10%
The Midstream Program displayed estimated savings of 144,314.62 Therms with a realization rate of
279.10%.The following table summarizes the incentive costs associated with the program.
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Avista Idaho PY2024
Table 3-20:Midstream Program Costs by Measure
Measure Incentive Costs
_G Natural Gas Furnace $696,600.00
_G Natural Gas Boiler $1,800.00 _
_G Natural Gas Storage Tank Water Heater _ $125.00 _
G Natural Gas Tankless Water Heater $11,125.00
Total I $709,650.00
The Evaluators describe the impact evaluation tasks completed for this program in the subsections
below.
3.2.5.1 Database Review& Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Midstream
Pilot.The Evaluators selected a subset of rebates to cross-verify tracking data inputs, summarized in
Section 2.2.2.3.
The Evaluators found the tracking data documented the information necessary to accurately
characterize savings for the program within the Idaho natural gas service territory.The Evaluators
verified the model number, efficiency, quantity, and RTF UES baselines necessary to calculate verified
savings for the census of rebated equipment in the program.The Midstream tracking data is tracked and
delivered separately from the remaining residential portfolio, often demonstrating extensive detail on
product characteristics.
3.2.5.2 Verification Survey
The Evaluators did not conduct verification surveys for the Midstream Program in PY2024 due to the
nature of the midstream delivery channel; customers are not aware that they are participating in the
program because they are not required to fill out a downstream rebate application.
3.2.5.3 Impact Analysis
For the natural gas furnace measure,the Evaluators calculated savings via a treatment-only billing
analysis as detailed in Section 2.2.3.6.This billing analysis yielded verified savings of 90.0 therms for
Idaho customers installing furnaces in 2024. The Evaluators calculated verified savings for all other
residential Midstream measures through industry standard engineering algorithms. When employing
these engineering algorithms,the Evaluators incorporated Regional Technical Forum-defined market
practice baselines from the appropriate RTF workbooks in place at the time of the biennium plan for the
Midstream Program.
3.2.5.4 Billing Analysis
This section details the billing analysis results for the residential gas furnace measure.As detailed above,
the Evaluators conducted a treatment-only regression billing analysis to determine gas furnace savings.
This analysis was identical to the one outlined in the Model 3: Gross Billing Analysis,Treatment-Only
Regression Model section above. Of note, savings were extrapolated using current year(as opposed to
TMY) HDD data so that the Evaluators would present the most accurate assessment of the gas saved by
participating Avista customers as of 2024(and early 2025).
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Avista Idaho PY2024
After data cleaning and preprocessing, 337 customers were included in the furnace billing analysis.The
regression had an adjusted R-squared of 0.78 suggesting the model predicts energy usage well.The
following table outlines key results associated with the regression.
Table 3-21. Furnace Billing Analysis Results
Treatment Annual I
Customers in Savings per •0' •0'
Analysis Customer Lower Cl Cl Squared
Natural Gas Furnace 337 90.00 74.81 105.20 0.78
Ultimately,the billing analysis yielded annual gas savings of 90.00 therms per household.This savings
value is consistent with other gas furnace analyses the Evaluators have conducted.
3.2.5.5 Verified Savings
The Evaluators reviewed the implementer expected savings values along with verified tracking data to
estimate net adjusted program savings for those measures. In order to calculate verified savings, the
Evaluators employed a billing analysis or utilized industry-standard engineering algorithms using
purchased equipment efficiency values and RTF-defined market practice baseline values,where
appropriate.The Midstream Program displayed a 279.10% realization with 144,314.62 therms saved, as
displayed in Table 3-19.This shows a marked improvement in expected savings calculations
methodology from the previous year.
In particular,the furnace verified gas savings calculated via billing analyses were substantially higher
than ex-ante expected savings, leading to a 298.14% realization rate.The Evaluators recommend Avista
estimate furnace savings based on billing analysis results.The furnace billing analysis the Evaluators ran
suggests that Avista's Idaho customers have substantially higher gas savings than RTF estimates.
Updating ex-ante savings estimates to reflect these findings seems worthwhile.
For other Midstream measures, the Evaluators would recommend Avista continue incorporating
Regional Technical Forum market practice baseline values to estimate regional savings. Because
downstream measures of the same category are similarly evaluated by comparing against market
practice baseline in the Pacific Northwest,the Evaluators deem this counterfactual scenario is relevant
for a midstream delivery channel offering incentives for the same equipment and recommend this
methodology to estimate and evaluate non-furnace Midstream measures moving forward.
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Avista Idaho PY2024
3.2.6 Home Energy Audit Program
The Residential Home Energy Audit Program is designed to educate and generate interest in efficiency in
general and, more specifically, in Avista's portfolio of residential energy efficiency and renewable-energy
programs.The Evaluators completed a billing analysis of the census of participants to identify the
educational impact of the program on customers' energy usage behaviors while removing savings
claimed and verified from other program participation.The following table summarizes the verified
natural gas energy savings for the Home Energy Audit Program impact evaluation.
Table 3-22:Home Energy Audit Program Verified Natural Gas Savings
PY2024 Expected 1 Adjusted Verified Verified
Measure Participation Savings Savings Savings Realization
(kWh) (kWh) (kWh) Rate
Home Energy Audit_ 263 NA NA NA NA
Total 263 NA NA NA NA
The Evaluators were unable to identify and estimate statistically significant natural gas savings in the
participant population through observed billing data.Avista did not estimate claimed savings for this
program, and therefore the realization rate is not applicable to the program.The following table
summarizes the incentive costs associated with the program.
Table 3-23:Home Energy Audit Program Costs by Measure
Measure Incentive Costs
Home Energy Audit $0.00
Total $0.00
The Evaluators summarize the program-specific impact analysis activities, results, conclusions, and
recommendations for the Home Energy Audit Program in the section below.
3.2.6.1 Database Review& Verification
The following sections describe the Evaluator's database review and document verification findings for
the Home Energy Audit Program.
3.2.6.2 Database Review&Document Verification
Before conducting the billing analysis,the Evaluators conducted a database review for the Home Energy
Audit Program.The Evaluators reviewed the list of participants of the Home Energy Audit Program in
PY2024.The Evaluators identified participating customers with natural gas service in the Idaho service
territory.The Evaluators found no duplicate participants in the project data and found that program
data appropriately reflected customer rate information.
3.2.6.3 Verification Surveys
The Evaluators did not conduct verification surveys for the Home Energy Audit Program in PY2024.
3.2.6.4 Impact Analysis
The Evaluators conducted the following impact evaluation methodologies to attempt to estimate
verified net energy savings in the Residential Home Energy Audit Program:
■ Billing Analysis with counterfactual group (IPMVP Option C)
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Avista Idaho PY2024
This program provides direct install measures to customers.The Avista auditor may provide
recommendations for improvements that may be rebated through Avista's programs. In addition, the
Avista auditor may also provide recommendations for home improvements that Avista does not
currently incent for.Therefore, in order to capture this combination of effects,ADM conducted a billing
analysis with a counterfactual group selected via propensity score matching.
The measures rebated by the customer through other Avista channels were removed from the average
household billing analysis results, in order to remove double counting effects. Due to the participation
rate,the Evaluators included Washington Electric, Washington Gas, Idaho Electric, and Idaho gas
participants in the census billing analysis. However,the Evaluators found the billing analysis did not
result in statistically significant natural gas impacts for the program.This is likely due to high variance in
participating household energy usage and combined with the small magnitude of potential behavioral
savings, a large treatment group is often recommended to identify a small treatment effect. The
Evaluators will attempt to estimate statistically significant savings through billing analysis in PY2025
using extended participant data.
3.2.6.5 Verified Savings
The Evaluators conducted a census billing analysis to estimate the impacts of the education efforts of
the Home Energy Audit Program. However,this effort did not result in statistically significant natural gas
impacts13.The Evaluators recommend re-attempting a billing analysis in PY2025 with extended
participant data.
13 The Evaluators successfully quantified electric impacts through the Home Energy Audit Program,reflected in the Idaho Electric
Impact Evaluation Report.
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Avista Idaho PY2024
3.2.7 On Bill Repayment Program
The On-Bill Repayment/Financing Program provides on-bill repayment/financing programs for
residential and small business customers.Avista's on-bill repayment (OBR)/financing program returned
as an offering after a half decade hiatus. In 2023 Avista started offering customers access to OBR
through its partner the Puget Sound Cooperative Credit Union (PSCCU). OBR,through PSCCU, offers
lower rate loans for energy-efficient projects to homeowners and business owners that can be more
easily tracked and paid back through their monthly utility bill. OBR is not intended for customers who
qualify for Avista's Low-Income Program and that can therefore be served directly through the
partnering community action agencies.
Avista does not claim energy savings for OBR, as the savings associated with any measure installed using
OBR financial support is claimed through the relevant and native Avista program. However, Avista
intends to claim additional educational and behavioral impacts through the OBR Program.
During the PY2024 impact evaluation, the Evaluators did not conduct an impact evaluation for the On
Bill Repayment Program.The Evaluators intend to conduct an impact evaluation of this program in
PY2025, as it is a "low risk" program. Additionally,there was no program participation for Idaho
customers in PY2024.
Table 3-24: On Bill Repayment Program Claimed Natural Gas Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
On Bill Repayment 0 NA NA NA NA
Total 0 NA NA NA NA
Avista does not quantify expected savings for the OBR Program.The following table summarizes the
incentive costs associated with the program.
Table 3-25:On Bill Repayment Program Claimed Costs by Measure
Measure Incentive Costs
On Bill Repayment $0.00
Total $0.00
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Avista Idaho PY2024
4. Low-Income Impact Evaluation Results
The Low-Income Program delivers energy efficiency measures to low-income residential customers in its
Idaho service territory with a partnership with five network Community Action Agencies ("Agencies")
and one tribal weatherization organization.The Agencies qualify income to prioritize and treat
households based on several characteristics. In-house or contract crews install approved program
measures. In addition,the Agencies have access to other monetary resources which allow them to
weatherize a home or install additional energy efficiency measures.
The Evaluators did not complete an impact evaluation on Avista's Low-Income Program. However,the
Low-Income Program will be evaluated in PY2025. For the purposes of this report,the expected savings
claimed by Avista is summarized in this section for the Low-Income Program. Table 4-1 summarizes the
Low-Income verified impact savings by program.
Table 4-1:Low-Income Verified Impact Savings by Program
Program Expected Savings Verified Savings(Therms) Verified Realization Rate
Low-Income 1,380.11 NA NA
Total Low-Income 1,380.11 NA NA
In PY2024,Avista completed and provided incentives for low-income gas measures in Idaho and
achieved total natural gas savings of 1,380 Therms.
4.1 Program-Level Impact Evaluation Results
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Low-Income sector in the section below.
4.1.1 Low-Income Program
As specified in the previous section,the Evaluators did not complete an impact evaluation on Avista's
Low-Income Program. For the purposes of this report,the expected savings claimed by Avista is
summarized in this section for the Low-Income Program. Table 4-2 summarizes the measures offered
under this program.
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Avista Idaho PY2024
Table 4-2:Low-Income Program Measures
Measure Impact Analysis .. . .•
G Air Infiltration
G Attic Insulation With Natural Gas Heat
G Duct Insulation
G Duct Sealing
G Exterior Doors
G Floor Insulation Avista TRM
G Health Safety and Repair
G Natural Gas Furnace
G 50 Gallon Natural Gas Water Heater
G Tankless Natural Gas Water Heater
G Window Replc With Natural Gas Heat
Table 4-3 summarizes the claimed natural gas savings for the Low-Income Program.
Table 4-3:Low-Income Program Claimed Natural Gas Savings
r- , 1xpected_Fdjusted7 Verified Verified
Measure PY2023 Savings Savings Savings Realization
Participation (Therms) 7(Therms) (Therms) Rate
G Air Infiltration 2 24.46 NA NA NA
G Attic Insulation With Natural Gas Heat 2 210.6 NA NA NA
G Duct Insulation 1 7 NA NA NA
G Duct Sealing 2 40.34 NA NA NA
G Exterior Doors 2 19.32 NA NA NA
G Floor Insulation 1 78.68 NA NA NA
G Health Safety and Repair 9 0 NA NA NA
G Natural Gas Furnace 14 871.36 NA NA NA
G 50 Gallon Natural Gas Water Heater 2 14.1 NA NA NA
G Tankless Natural Gas Water Heater 1 66.5 NA NA NA
G Window Replc With Natural Gas Heat 3 47.75 NA NA NA
Total 39 1,380.11 NA NA NA
The following table summarizes the incentive costs associated with the program.
Table 4-4:Low-Income Program Costs
Measure Incentive Costs
G Air Infiltration $168.92
G Attic Insulation With Natural Gas Heat $3,363.75
G Duct Insulation $110.40
G Duct Sealing $271.00
G Exterior Doors $1,355.00
G Floor Insulation $1,253.82
G Health Safety and Repair $55,332.25
G Natural Gas Furnace $106,501.09
G 50 Gallon Natural Gas Water Heater $8,367.15
G Tankless Natural Gas Water Heater $4,188.30
G Window Replc With Natural Gas Heat $5,118.05
Total $186,029.73
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Avista Idaho PY2024
S. Nonresidential Impact Evaluation Results
The Evaluators completed an impact evaluation on Avista's Non-Residential portfolio to verify program-
level and measure-level energy savings for PY2024.The following sections summarize findings for each
natural gas impact evaluation in the Non-Residential Portfolio in the Idaho service territory.The
Evaluators used data collected and reported in the tracking database, online application forms,Avista
TRM 2024, RTF, IPMVP, supplemental sources and billing analysis of participants to evaluate savings.
The approach selected for each program allowed for the strongest estimate of achieved savings practical
for each program, dependent on each program's delivery method, magnitude of savings, number of
participants, and availability of data. Table 5-1 summarizes the Non-Residential verified impact savings
by program.
Table 5-1: Non-Residential Verified Impact Savings by Program
Expected Savings Adjusted Savings Verified Savings Verified
(Therms) (Therms) (Therms) Realization Rate
HVAC No PY2024 Participation
Shell 3,600 3,600 3,600 100.0%
Midstream (NR) 26,804 25,594 24,769 92.4%
Site-Specific 5,408 5,408 4,818 89.1%
Total 35,812 34,602 33,187 92.7%
In PY2024,Avista completed and provided incentives for non-residential natural gas measures in Idaho
and reported total natural gas energy savings of 33,187 Therms. All programs exceeded savings claims,
leading to an overall achievement of 92.7%of the expected savings for the non-residential programs.
Further details of the impact evaluation results by program are provided in the sections following.
5.1 Verification Results
Before conducting the impact analyses,the Evaluators conducted a database review for all prescriptive
programs.The Evaluators selected a random subset of rebate applications and associated documents
from participating customers to cross-verify tracking data inputs.These documents included invoices,
rebate applications, pictures,AHRI certificates and similar types of documents for the Shell Program.
This sample of documents was used to cross-verify tracking data inputs. In the case the Evaluators found
any deviations between the tracking data and application values,the Evaluators reported and
summarized those differences in the appropriate report chapters.
The Evaluators developed a sampling plan that achieves a sampling precision of±10%at 90%statistical
confidence—or"90/10 precision"—to estimate the percentage of projects for which the claimed savings
are verified or require some adjustment.
Table 5-2 displays program populations, sample sizes for document verification and resulting precision.
Measurement and Evaluation Report 46

Avista Idaho PY2024
Table 5-2:Non-Residential Program-level Verification Precision
Program Population Sampled Precision
Shell 5 5 ±0.0%
MidstreaM14 112 105 ±9.27%
Site-Specific 3 3 ±0.0%
5.1.1 On-Site Verification
Unlike residential measures, non-residential measures typically have a 100% installation rate or a
deemed in-service rate (ISR) included in RTF and Avista TRM UES. The exception to this rule is custom
projects, such as those in the Site-Specific programs. For this the Evaluators conducted two on-site visits
to verify full installation and equipment operation as described in the project scope.
5.2 Program-Level Impact Evaluation Results
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
for the Non-Residential sector in the section below.
14 By design,the Midstream program tracking data is per measure, rather than per project. The number 43 represents the total
number of measures verified using make/model info included in tracking data.
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Avista Idaho PY2024
5.2.1 Prescriptive HVAC Program
The Prescriptive Natural Gas HVAC Program encourages customers to select highly efficient natural gas
heating equipment solutions for their business. Installing high efficiency equipment helps lower
operating costs and save energy.The prescriptive rebate approach issues payment to the customer after
the measure has been installed. Commercial customers who heat with Avista natural gas are eligible for
this program. Customers must submit a completed rebate form, invoices, and an AHRI certificate within
90 days after the installation has been completed.
Table 5-3 summarizes the measures rebated in PY2024 under this program.
Table 5-3:Prescriptive HVAC Program Measures
MethodologyMeasure Impact Analysis
Natural Gas Boiler Avista TRM UES
Multi-Stage Furnace Avista TRM UES
Single-Stage Furnace Avista TRM UES
Unit Heater Avista TRM UES
In PY2024 there were no participation or claimed kWh savings from the Prescriptive HVAC Program.
Table 5-4:Prescriptive HVAC Program Verified Natural Gas Savings
PY2024 Expected Adjusted Verified Realization
Participation Therm Savings Therm Savings Therm Savings Rate
(Savings Units)
Totals: 0 0 0 0 1 N/A
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Avista Idaho PY2024
5.2.2 Prescriptive Shell Program
The Commercial Prescriptive Shell Program offers incentives to commercial customers who improve the
envelopes of their existing buildings by adding insulation, which may make a business more energy-
efficient and comfortable. Avista issues payment to the customer after the measure has been installed
by a licensed contractor. Commercial customers must have an annual heating footprint for a fuel
provided by Avista.
Customers must submit a completed rebate form, invoices, and an insulation certificate within 90 days
after the installation has been completed. Avista will send incentive checks to customers or their
designees after each project is approved.This program is promoted by trade allies, Avista account
executives, the Avista website, and Avista marketing efforts. Avista's website is also used to
communicate program requirements, incentives, and forms.
Table 5-5 summarizes the measures rebated in PY2024 under this program.
Table 5-5:Prescriptive Shell Program Measures
MethodologyMeasure Impact Analysis
Attic Insulation Avista TRM UES
Wall Insulation Avista TRM UES
The following table summarizes the claimed, adjusted and verified therm savings for the program.
Table 5-6:Prescriptive Shell Program Verified Natural Gas Savings
PY2024 Expected Adjusted Verified
ParticipationMeasure
(Projects) Savings Savings Savings Rate
Attic=<R11 to 1130-1144 1 432 432 432 100.0%
Attic=<R11 to R45+ 3 2,018 2,018 2,018 100.0%
Wall=<R4 to R11-R19 2 853 853 853 100.0%
Wall=<R4 to 19+ 1 297 297 297 100.0%
Totals 7 3,600 3,600 3,600 100.0%
The following table summarizes the incentive costs associated with the program.
Table 5-7:Prescriptive Shell Program Costs by MeasurW' Measure Measure Count(Square Feet Incentive Costs
Installed)Attic=<R11 to 1130-1144 4,800 $4,800
Attic=<R11 to R45+ 15,520 $18,954
Wall=<R4 to R11-R19 3,556 $3,556
Wall=<R4 to 19+ 824 $1,030
Totals 24,700 $28,340
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Prescriptive Shell Program in the section below.
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Avista Idaho PY2024
5.2.2.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Prescriptive
Shell Program.The Evaluators reviewed all rebate applications to cross-verify tracking data inputs,
summarized in Section 2.2.2.3. Data points checked between project applications and program tracking
data include R-levels, square footage of installation, HVAC configuration and measure cost values.
Below,Table 5-8 shows the project population,the number of projects checked and the overall
precision.
Table 5-8:Prescriptive Shell Program Verification Precision
Population . - .
Precision
7 7 ±0%
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Prescriptive Shell Program and there were no substantive deviations between program tracking data
and project documents.
5.2.2.2 Impact Analysis
This section summarizes the verified savings results for the Shell Program.The Evaluators calculated
verified savings for the natural gas measures using the active Avista TRM values. Final verified savings
were calculated by applying the appropriate UES to a census of measures.
5.2.2.3 Verified Savings
The Evaluators reviewed and applied the current TRM UES values for the Attic and Wall Insulation
measures along with verified tracking data to estimate net program savings for this measure.The
verified savings for the program is 3,600 therms with a realization rate of 100.0%, as displayed in Table
5-6. Evaluators did not find any deviations from TRM UES.
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Avista Idaho PY2024
5.2.3 Nonresidential Midstream Program
Avista designed the Midstream Program to shift the onus of applying for rebates from end-use
customers to distributors. Not only does this reduce customers'/contractors' administrative burden (i.e.,
no need to submit paperwork tracking energy efficient installations), but it is also anticipated to increase
high-efficiency equipment options at competitive prices. Midstream rebates provide an immediate
discount on eligible products, which appear as a line item on customer invoices. Starting on July 1, 2023,
the Midstream Program replaced Avista's residential and commercial downstream space-heating and
water-heating programs as well as the commercial food service equipment rebate program.
Through the Midstream Program,Avista seeks to achieve three overall objectives:
■ Provide greater long-term, cost-effective savings for residential and commercial customers
alike
■ Reduce Avista's administrative burden in processing space-heating, water-heating, and
commercial kitchen equipment applications
■ Accelerate the market transformation of energy-efficient equipment
The Midstream Program provides bought-down equipment to both Residential and Commercial entities.
This chapter discusses and presents results only for the non-residential measures. See Section 3.2.5 the
residential portion.
Table 5-9 summarizes the measures rebated in PY2024 under this program.
Table 5-9:Non-Residential Midstream Program Measures
Category Measure Impact Savings Methodology
Combination Oven RTF Combination Ovens
Food Service Convection Oven RTF Convection Ovens
Dishwasher DOE CFS Calculator
Fryer RTF Fryers
Domestic Water Heating Instantaneous Water Heater Engineering Algorithm
Storage Water Heater Engineering Algorithm
HVAC Furnace Engineering Algorithm
Boiler RTF
The following table summarizes the verified electric energy savings for the Midstream Program impact
evaluation.
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Avista Idaho PY2024
Table 5-10:Non-Residential Midstream Program Verified Therms Savings
PY2024 Expected Adjusted Verified Realization
Measure Participation Savings Savings Savings Rate
(Measures) (Therms) (Therms) (Therms)
Boiler 2 4,966 4,966 4,945 99.6%
Combination Oven 2 534 534 534 99.9%
Convection Oven 3 384 384 384 100.0%
Dishwasher 4 678 678 678 100.0%
Fryer 18 6,284 5,621 5,621 89.5%
Furnace 87 9,787 9,787 10,988 112.3%
Instantaneous Water Heater 10 2,745 2,471 1,358 49.5%
Storage Water Heater 4 1,427 1,345 261 18.3%
Total 130 26,804 25,786 24,769 92.4%
The following table summarizes the incentive costs associated with the program.
Table 5-11: Non-Residential Midstream Program Incentives
111111�MIII Incentive Costs
Boiler 2 $21,000
Combination Oven 2 $5,200
Convection Oven 3 $4,200
Dishwasher 4 $0
Fryer 18 $22,050
Furnace 87 $81,990
Instantaneous Water Heater 10 $5,989
Storage Water Heater 4 $3,599
Totals 130 $144,027
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Midstream Program in the section below.
5.2.3.1 Database Review& Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Midstream
Program. Due to the program delivery pathway,the Program does not include project applications. For
this program,the Evaluators examined a representative sample of projects to ensure that program
tracking data accurately reflected measure characteristics used in assessing savings. Data points checked
include equipment configurations, capacities, and efficiency levels.
Table 5-12 shows the project population, the number of measures checked and the overall precision.
Table 5-12:Non-Residential Midstream Program Verification Precision
Population Sampled Precision qF
43 43 0.0
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Midstream Program and no substantive equipment specifications differed from those in the tracking
data.
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Avista Idaho PY2024
5.2.3.2 Impact Analysis
Once verification was completed, to estimate program savings for these measures the Evaluators
reviewed and applied the appropriate UES values from the RTF. If a measure was not covered by an RTF
entry then a UEF from the Avista TRM was used as the source for verified savings. For measures not
included in either the RTF or Avista TRM, verified savings were calculated using standard engineering
algorithms with project-specific specs and RTF inputs.
5.2.3.3 Verified Savings
The verified savings for the program are 24,769 Therms with a realization rate of 92.4%, as displayed in
Table 5-10. Below,the Evaluators discussed measures whose realization rates differ significantly from
100%:
■ Fryers: Expected savings were based on a general capacity category found in the RTF workbook,
however the Evaluators used RTF UES workbooks to verify savings for this measure, which were
specific to the equipment.The Evaluators applied the RTF capacity-specific UES to each project
appropriately, which resulted in are slightly lower project-level savings than expected and
claimed.
■ Instantaneous Water Heaters: Claimed savings were calculated based on therms saved per
input BTUh (rated) of the equipment and assumed average equipment sizing,whereas verified
savings calculations were carried out using standard engineering algorithms,which include
actual equipment specifications and annual water use.
■ Storage Water Heaters: Similar to instantaneous water heaters, claimed savings were calculated
based on Therms saved per input BTUh (rated) of the equipment and assumed average
equipment sizing, whereas verified savings calculations were carried out using standard
engineering algorithms, which include verified equipment specifications and annual water use.
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Avista Idaho PY2024
5.2.4 Site-Specific Program
The Site-Specific Program provides calculated incentives to support the installation of qualifying energy
efficiency equipment at commercial/industrial sites.These projects typically have a higher degree of
complexity than the traditional prescriptive offerings and rely on custom calculations of savings and
incentive levels. Examples of these projects include process improvements, upgrades to specialized
equipment used in manufacturing, lighting installations that rely on specialized controls, and other
measures designed around the customer's specific needs.
The program approach strives for a flexible response to energy efficiency projects that have
demonstrable therm savings within program criteria and are typically composed of custom HVAC,
envelope, and industrial process load projects that do not fit the prescriptive path. In PY2024 three
projects were completed, consisting of the replacement of heated pool covers and boiler replacements.
The following table summarizes the verified natural gas energy savings for the Site-Specific Program
impact evaluation.
Table 5-13:Site-Specific Program Verified Natural Gas Savings
PY2024 Expected Adjusted Verified Verified Realization
Participation Therm Savings Therm Savings Therm Savings Rate
3 5,408 5,408 4,818 89.1%
The Site-Specific Program displayed verified savings of 4,818 Therms with a realization rate of 89.1%
against the expected savings for the program.
Table 5-14:Site-Specific Program Costs
Program Incentive Costs
Site-Specific $18,928
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Site-Specific Program in the section below.
5.2.4.1 Sample Design
In their review,the Evaluators conducted reviews of all three natural gas savings projects completed
during the PY2024 program year.The Evaluators obtained the project-related documentation for
review.These documents typically included spec sheets, building characteristics,calculators, invoices,
project photos, and trending data. This information allowed the Evaluators to replicate claimed savings
estimates and develop M&V plans to be used in assessing verified savings and collecting on-site data.
Using project-specific M&V plans,the Evaluators visited sites to verify measure installation and
operating parameters, as well as building parameters and other data necessary to determine verified
savings.The Evaluators were able to conduct visits to two of the three project sites.
5.2.4.2 Impact Approaches and Verified Savings
SSOP 143056:The project is a music conservancy in a historic building. Existing windows were single
pane with a U-value of 1 and SHGC of 1. A total of 214 ftz of existing windows were replaced with
efficient double pain models with U-factors of 0.31 or 0.30 and a SHGC or .20 or 0.18, depending upon
Evaluation and Measurement Report 54

Avista Idaho PY2024
the specific window. Window projects typically produce savings too low to measure using a facility-level
regression analysis, so the Evaluators used engineering algorithms and weather specific to the facility's
geographic location to verify expected savings estimates. In doing so,the Evaluators calculated 426
verified therms, leading to a 90.3% realization rate.
SSOP 140807:The project is a four-unit strip mall/freestanding retail facility whose owner increased
insulation levels from R5 to R38 over 2,600 square feet in four suites.Verified savings were measured
via billing data regression analysis. The results show only 369 of the expected 913 therms in savings, or
40.5%. The regression model showed an excellent fit and robust variables. Regressions of individual
units show similar results. Materials used to develop expected savings were not available,thus the
Evaluators are not able to determine the cause to the difference. Multiple factors could cause verified
savings to be lower than expected, including changes in usage patterns of the facilities (such as a
temporary closure) or a poorly sealed structure (which allows conditioned air to escape to
unconditioned spaces).
SSOP 121987:The project is a ski and mountain bike resort whose owners replaced four(4) existing
boilers with high efficiency models used to heat water primarily for the lodging portion of the resort.
Project documents included the facility-level regression analysis used to produce expected savings. The
Evaluators recreated the analysis and determined it to be conducted correctly and the savings to be
statistically significant. Further,the Evaluators also performed a second analysis using engineering
algorithms for boiler retrofits, whose results firmly support the results of the billing analysis. Verified
savings are 4,023 therms, 100%of expectations.
Verified savings were developed for each site. Table 5-15 presents realization at the site level, with
program-level savings.
Table 5-15:Site-Specific Expected,Adjusted and Verified Therm Savings by Project
ExpectedProject ID
SSOP 143056 472 426 90.3%
SSOP 140807 913 369 40.5%
SSOP_121987 41023 4,023 100.0%
Totals 5,408 4,818 89.1
5.2.4.3 Verified Savings
The Site-Specific Program in total displays a realization rate of 89.1%with 4,818 Therms verified natural
gas energy savings in the Idaho service territory, as displayed in Table 5-16.
Table 5-16:Site-Specific Impact Summary
Expected Therm Savings Adjusted Therm Savings Verified Therm Savinis--T-Realization Rate
5,408 5,408 4,818 89.1%
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Avista Idaho PY2024
6.Appendix A: Summary of Survey Respondents
This section summarizes additional insights gathered from the simple verification surveys deployed by
the Evaluators for the impact evaluation of Avista's Residential and Low-Income Programs in PY2023. As
detailed previously, the Evaluators utilized the response results from this survey effort to incorporate in-
service rates into the PY2024 verified savings estimates. A full process evaluation and verification survey
effort will be implemented in PY2025.
Survey respondents confirmed installing between one and three measures that were rebated by Avista,
displayed in Table 6-1.This table is missing information from 29 low-income, CEEP, and MFDI survey
respondents who did not indicate the number nor type of measures they received.
Table 6-1: Type and Number of Measures Received by Respondents
Measure Category Total Percent(n=305)
No Measures 304 13.8%
One Measure 1218 55.4%
Two Measures 440 20.0%
Three Measures 171 7.8%
Four Measures 47 2.1%
Five or more measures 20 0.9%
H VAC 289 13.1
Water Heater 136 6.2%
Smart Thermostat 515 23.4%
Clothes Washer 297 13.5%
Clothes Dryer 189 8.6%
The Evaluators asked respondents to provide information regarding their home, as displayed in Table
6-2. Similar to previous impact evaluation findings,the majority of respondents noted owning a single-
family home between 1,000-3,000 square feet with central air conditioning.
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Avista Idaho PY2024
Table 6-2:Survey Respondent Home Characteristics"
.. Percent
Own 93.8%
Rent 1.9%
Do you rent your home?(n=755) Own and rent to someone else 1.3%
1 don't know 0.1%
Prefer not to answer 2.9%
Single-family house detached 86.0%
Single-family house attached to 2 3%
one or more other houses
Mobile or manufactured home 8.2%
Which of the following best Apartment with 2 to 4 units 0.8%
describes your home? (n=755)
Apartment with 5+units 0.3%
Other 1.4%
1 don't know 0.2%
Prefer not to answer 0.7%
Does your home have central air Yes 72.6%
conditioning?(n=755)
Less than 1,000 ftZ 6.6%
1,000-1,999 ftZ 42.4%
About how many square feet is Z o
your home?(n=629) 2,000-2,999 ft 32.3/
3,000-3,999 ftZ 13.5%
4,000 ftZ or more 5.2%
Before 1950 20.0%
1950 to 1959 10.3%
1960 to 1969 6.6%
When was your home built? 1970 to 1979 15.3%
(n=719) 1980 to 1989 7.7%
1990 to 1999 15.3%
2000 to 2009 13.2%
2010 to 2019 4.7%
2020 to Present 5.6%
1 don't know 1.1%
Prefer not to answer 0.2%
is Four contractors or construction companies were not asked these questions.
Evaluation and Measurement Report 57

APPENDIX C - 2024 COST- EFFECTIVENESS TABLES
Electric
Electric Portfolio
Cost-Effectiveness Test
..
TRC $ 23,222,846 $ 28,252,370 0.82
UCT $ 23,222,846 $ 16,510,052 1.41
PCT $ 37,174,523 $ 25,693,995 1.45
RIM $ 23,222,846 $ 18,633,116 1.25
Electric Portfolio (Without Low-Income)
Cost-Effectiveness Test Benefits Costs
TRC $ 23,097,518 $ 28,003,903 0.82
UCT $ 23,097,518 $ 16,282,545 1.42
PCT $ 36,835,495 $ 25,459,335 1.45
RIM $ 23,097,518 $ 18,401,040 1.26
Commercial/industrial
Cost-Effectiveness Test Benefits Benefit/Cost Ratio
TRC $ 18,758,389 $ 26,148,400 0.72
UCT $ 18,758,389 $ 15,135,905 1.24
PCT $ 31,827,752 $ 24,081,858 1.32
RIM $ 18,758,389 $ 17,086,053 1.10
Residential
Cost-Effectiveness Test Benefits Costs Benefit/Cost Ratio
TRC $ 4,339,129 $ 1,855,502 2.34
UCT $ 4,339,129 $ 1,146,640 3.78
PCT $ 5,007,744 $ 1,377,477 3.64
RIM $ 4,339,129 $ 1,314,988 3.30
Low-Income
Cost-Effectiveness Test
TRC $ 125,328$ 248,467 0.50
UCT $ 125,328$ 227,507 0.55
PCT $ 339,028$ 234,660 1.44
RIM $ 125,328$ 232,075 0.54
2024 Idaho Annual Conservation Report Appendices

NATURAL GAS
Natural Gas Portfolio
Cost-Effectiveness Test
TRC $ 2,052,929$ 1,660,247 1.24
UCT $ 2,052,929$ 1,962,187 1.05
PCT $ 3,633,250$ 1,020,983 3.56
RIM $ 2,052,929$ 2,090,636 0.98
Natural Gas Portfolio (Without Low-Income)
Cost-Effectiveness Test Ben.fit/Cost Rti.
TRC $ 2,03a335$ 1,452,188 1.40
UCT $ 2,03a335$ 1,773,443 1.15
PCT $ 3,432,627$ 815,639 4.21
RIM $ 2,03a335$ 1,901,087 1.07
Commercial/Industrial
I Cost-Effectiveness Test
TRC $ 238,463$ 300,269 0.79
UCT $ 23a463$ 235,653 1.01
PCT $ 429,759$ 236,108 1.82
RIM $ 23a463$ 255,005 0.94
Residential
Cost-Effectiveness Test
TRC $ 1,799,871 $ 1,151,918 1.56
UCT $ 1,799,871 $ 1,537,790 1.17
PCT $ 3,002,867$ 579,530 5.18
RIM $ 1,799,871 $ 1,6%082 1.09
Low-Income
Cost-Effectiveness Test
TRC $ 14,594$ 208,059 0.07
UCT $ 14,594$ 188,744 Q08
PCT $ 200,624$ 205,345 0.98
RIM $ 14,594$ 189,549 Q08
2024 Idaho Annual Conservation Report Appendices

APPENDIX D - 2024 EXPENDITURES BY PROGRAM
Program Natural Gas Total
Energy Efficiency
Low-Income/CEEP
Low-Income $ 213,700$ 186,030$ 399,73
Residential
Shell $ 161,589$ 430,006$ 591,594
Fuel-Efficiency $ 30,300$ -$ 3Q300
ENERGY STAR/NEEM Manufactured Housing Program $ 26,000$ -$ 26
Appliances $ 50,726$ 63,340$ 114,066
Midstream $ 400,000$ 709,650$ 1,109,E
Home Energy Audit $ _$ _ $
On-Bill Repayment $ _$ $
Commercial/industrial
Prescriptive Lighting $ 2,297,810$ $ 2,297,81
Small Business Direct-Install Lighting $ 9,497,604$ $ 9,497,604
Commercial Prescriptive HVAC VFD Retrofit $ 12,443$ $ 1 Z44
Commercial Grocer $ 4,400$ $ 4,
Commercial Shell $ 9,814$ 28,340$ 154
Green Motors Rewind $ $ $
Midstream $ 84,815$ 144,028$ 228,84
Site-Specific $ 1,162,477$ 18,928$ 1,181,40
Building Operator Certification $ _$ _ $
Energy Efficiency Total $ 13,951,677$ 1,580,322$ 15,531,
Market Transformation
Northwest Energy Efficiency Alliance $ 679,292$ 188,004$ 867,29
Market Transformation Total $ 679,292$ 188,004$ 867,2
Other Programs and Activities
General Implementation $ 757,200$ 27,639$ 784,83
Labor Costs $ 1,597,621 $ 223,797$ 1,821,41
Marketing and Outreach $ 285,997$ 31,644$ 317,64
Third-Party Implementation $ 203,524$ 130,423$ 333,946
Pilot Programs $ 4,941 $ 573$ 5,51
EM&V/CPA $ 144,091 $ 75,883$ 219,97
Other $ 30$ 7$ 3
Other Programs and Activities Total $ 2,993,404$ 489,966$ 3,483,37
Grand Total $ 17,624,373$ 2,258,292$ 19,882
2024 Idaho Annual Conservation Report Appendices

APPENDIX E - 2024 ENERGY-EFFICIENCY ACTIVITY BY PROGRAM
Electric Natural Gas W
Evaluated
Energy-Efficiency Program Participants Savings Utility Cost Utility Cost
7 (kWh)__ IMEM
Weatherization 34 Homes 20,703 $ 85,894 13 Homes 428 $ 1Z840
HVAC 8 Units 44,074 $ 116,320 14 Units 871 $ 107,902
Water Heat - Units - $ - 3 Units 81 $ 12,67
Lighting 10 Units 62 $ 286 - NA - $ -
Health and Safety I I HHS - $ 23,003 9 HHS $ 55,33
ENERGY STAR Refrigerator I Units 39 $ 2,005 - NA $
Low-Income Total 64 64,878 $ 227,507 39 1,380 $ 188,744
Residential
Units Units
Shell 899 (Measures) 107,769 $ 194,083 511 (Measures) 20,905 $ 487,91
ENERGY STAR/NEEM 26 Homes 77,951 $ 68,628 - Homes - $ -
Manufactured Housing Program
Units Units
Multifamily Weatherization 65 (Measures) 108,911 $ 85,265 23 (Measures) 1,166 $ 8,204
Appliances 575 Units
nit sures) 92,354 $ 53,240 495 Units cures) 19,327 $ 82,892
(MeUnits Units
Midstream 897 (Measures) 1,891,168 $ 697,996 1,640 (Measures) 144,315 $ 958,776
Units
Fuel-Efficiency IS (Measures) 103,207 $ 47,308 - NA - $ -
Home Energy Audit 120 Homes 9,418 $ 120 263 Homes $
Units -
On-Bill Repayment (Measures) $ (Measures) $
Residential Total Z597 2,390,778 $ 1,146,640 2,932 185,712 $ 1,537,790
Units
Prescriptive Lighting 68,780 (Measures) 6,888,637 $ 2,822,203 NA $
Small Business Direct-Install 618 Projects 15,161,166 $ 10,553,584 NA $
Lighting
Commercial Prescriptive HVAC 2 Projects 1 15,1 1 1 $ 18,096 Projects $
VFD Retrofit
Commercial Grocer 58 Projects 37,199 $ 7,659 Projects $ -
Commercial Shell 7 Projects 16,263 $ I Z 157 7 Projects 3,600 $ 34,495
Motor
Green Motors Rewind - Rewind - $ - - NA - $ -
Midstream 105 Projects 172,150 $ 99,033 130 Projects 24,769 $ 176,961
Site-Specific 18 Projects 5,185,350 $ 1,619,545 3 Projects 4,818 $ 24,197
Building Operator Certification I Projects 119,000 $ 3,628 - NA - $ -
Commercial/Industrial Total 69,589 27,694,876 $ 15,135,905 140 33,187 $ 235,653
Energy Efficiency Total 72,250 30,150,532 $ 16,510,052 3,1 1 1 220,279 $ 1,962,187
2024 Idaho Annual Conservation Report Appendices

APPENDIX F - NEEA 2024 ANNUAL SAVINGS REPORT - ELECTRIC
Memorandum >>
March 26, 2025 neea
TO: Nicole Hydzik, Director of Energy Efficiency,Avista Utilities; Meghan Pinch, Manager
of Program Managers,Avista Utilities; Kim Boynton, Manager of Planning and
Analytics,Avista Utilities
CC: Becky Walker,Chief Program Officer;Stephanie Rider; Director Portfolio
Management, Data Strategy and External Reporting, Nathan Martinez,Director,
Market Analytics, Research and Evaluation;Virginia Mersereau,Vice President of
Corporate Strategy and Communications
FROM: Christina Steinhoff, Principal Planning Analyst, NEEA Data, Planning and Analytics
SUBJECT: Final 2024 Annual Savings Report
NEEA is an alliance of utilities and energy efficiency organizations that pools resources and shares
risks to transform markets toward energy efficiency that benefits consumers and businesses in the
Northwest. At its heart, NEEA is a collaborative organization that works with all parts of the
market to enable efficient technology choices for consumers:gathering and analyzing data to
inform both regional power planning and utility programs,leveraging its relationships with mid
and upstream market actors like manufactures and retailers,and improving how products are
tested and perform in real life applications.Activities include:
• Providing data and insights to understand how the market is responding to the technology
solutions to inform resource planning and identify new opportunities and product options
for energy efficiency.
• Providing Avista with an up-to-date,neutral,and representative characterization of existing
Northwest building stock and energy trends,which inform market transformation
programs and identify opportunities for private sector investment.
• Leveraging trusted relationships with the supply chain to share insights on how well new
technologies perform,save energy,and reduce waste.
• Creating product specifications to guide how companies can voluntarily adjust their
products to be more efficient and meet various needs throughout the region,getting as
much energy savings as possible while ensuring products deliver customer benefits. In
tandem, NEEA works midstream with retailers and distributors to expand the range of
customer options in Montana stores and collect information on what's being sold in Avista
Utilities' Idaho service territory.
• Aggregating and leveraging the power of the region to identify and vet emerging
technologies and then create the market conditions necessary for them to take hold.The
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2024 Idaho Annual Conservation Report Appendices

alliance also helps Avista Utilities Idaho capture energy savings through these voluntary
interventions and by informing codes and standards that represent consumer and business
needs.
One outcome of NEEA's work over time is energy savings in Avista Utilities' Idaho service territory.
For 2024,NEEA is reporting 0.79 aMW of first-year energy savings. This value is an increase of
16%over what NEEA reported in 2023.
Some of the highlights of NEEA's work bringing direct benefit to Avista Utilities' Idaho customers
include:
• Adding two new distributors of efficient pumps in Idaho to the program,providing
additional data and influence in the local market
• Working with manufacturers to bring low cost,efficient clothes dryers to the market
• Completing several studies that Avista Utilities can access to provide data and intel for their
local efforts
This memo provides more information about:
1. 2024 savings estimates based on the market transformation work of NEEA affecting Idaho
and eastern Oregon over the past years.
2. 2023 Updates based on new market and technical data showing additional savings in
Avista Utilities' Idaho service territory.
3. Other updates highlighting work NEEA completed in 2024 to support Avista Utilities' Idaho
energy and program planning needs.
Details about allocation, baseline,and technical assumptions are in the attached Excel
spreadsheet.
Please contact Christina Steinhoff,Principal Analyst,at [e-mail] with any questions
about this report.
Final 2024 Savings Estimate Summary
NEEA estimates Avista Utilities' Idaho 2024 annual electric energy savings associated with its
initiatives is 0.79 aMW(Table 1).To calculate the savings, NEEA removes an estimate of savings
occurring from naturally occurring adoption based on baseline trends in the Northwest,and
savings reported through Avista Utilities' Idaho local incentive programs(Appendix A).
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2024 Idaho Annual Conservation Report Appendices

Table 1:2024 Annual Report Savings Estimates(aMW)
Residential 0.40
Commercial 0.35
Industrial 0.04
Agricultural 0.00
Notes:The values represented are rounded to the hundredth decimal in this summary table. See the
accompanying excel workbook for the detailed figures.These are site-based,first year electric savings.Net
Market Effects=Total Regional Savings-Local Program Savings-Baseline Savings,
2023 Annual Report Updates
NEEA updates its historical savings estimates based on new data. For 2023,the savings increased
from 0.68 to 0.69 aMW based additional data. NEEA was able to match additional models to
ENERGY STAR qualifying levels based on new data for both clothes dryers and televisions.Savings
increased by 0.01 aMW.
More details about the updates are available in the attached spreadsheet Variance 2023
worksheet.
2024 Highlights
NEEA works with all parts of the market to enable efficient technology choices for consumers:
gathering and analyzing data to inform both regional power planning and utility programs,
leveraging its relationships with mid and upstream market actors like manufactures and retailers,
and improving how products are tested and perform in real life applications.This work brings
more efficient products and options to the market,which are made available to consumers and
business across the Northwest through their local utilities.The sections below highlight that work
for 2024.
Consumer Products
NEEA works with extra-regional program administrators and national retailers to utilize midstream
incentives that signal energy efficient options in the supply chain while gaining access to full-
category sales data.The incentives encourage manufacturers and retailers to build,purchase,
stock and promote high-efficiency products. Products include white goods,air cleaners,
Net Market Effects is savings above the Naturally Occurring Market Baseline established at the start of a program net of
utility program savings.
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2024 Idaho Annual Conservation Report Appendices

televisions and other home electronics.The data retailers provide allows NEEA to identify the most
promising affordable energy efficiency opportunities and gain insights that improve energy test
procedures,helping consumers distinguish between products.The program saw momentum for
both laundry and television products in 2024.
• Laundry:The sales volume of residential laundry centersz has increased by 62%from 2023
to 2024(41,000 regional sales in 2024),driven in large part by products that incorporate a
heat pump dryer which make up 30%of the laundry center sales in 2024. NEEA influenced
advancement of heat pump drying technology as part of its Super-Efficient Dryers program
dating back to 2012.Additionally,the market share for ENERGY STAR dryers in the
standalone market rose from approximately 45%to 47%.This change indicates an upward
trend in market share growth for ENERGY STAR dryers.
• Televisions: NEEA is continuing to expand its data pipeline to effectively track the market
adoption of ENERGY STAR version 9 televisions—a specification developed by NEEA and its
partners. Using product test data that was recently published in the California Energy
Commission's Appliance Efficiency Database and sales data NEEA purchases for the
Northwest region,the Retail Products Portfolio program can estimate that as much as 26%
of the sales meet the ENERGY STAR criteria. NEEA's Retail Products Portfolio is now adding
televisions to its midstream program to increase certification levels and gather more
market intelligence.
Water Heating
NEEA influenced early adoption of heat pump water heaters in the Northwest by promoting
awareness of the product's benefits and building a strong foundation in the Northwest.3 In May
2024,the Department of Energy published a final rule mandating a shift for most electric storage
water heaters to heat pump technology by 2029. NEEA's ongoing engagement is crucial for
addressing market barriers and preparing the region to adopt and benefit from the recently
adopted federal standard. NEEA is supporting the Northwest market by working to strengthen the
workforce and engage both regionally and nationally to identify solutions to increase adoption of
these water heaters across the region,with particular focus on areas with slower adoption rates.
Space Heating
NEEA has been working in the residential space-heating market since the early 2000s starting with
ductless heat pumps and now moving toward advanced heat pumps.The Ductless Heat Pumps
2 A single product that does both washing and drying,either in the form of a connected,stacked machine or an all-in-one
combo unit.
3 NMR Group,Inc.2023.Heat Pump Water Heater Market Progress Evaluation Report#7.
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2024 Idaho Annual Conservation Report Appendices

program accelerated market acceptance and adoption of inverter-driven ductless heat pumps in
electrically heated homes through establishing relationships with manufacturers,distributors,and
retailers to enhance product design and availability. NEEA is now leveraging these relations to
work on a set of low-and no-cost improvements that meaningfully increase installed heat pump
system efficiency. In 2024, NEEA focused on building the market's awareness and capacity for
competitively differentiating these advanced heat pump improvements,with efforts on several
fronts.
NEEA's leadership and participation in 2024 contributed to updated specifications adopted into: 1)
to the Consortium for Energy Efficiency Residential Electric HVAC Specification,2)ENERGY STAR
Product Specification v.6.2 for Central Air Conditioners and Heat Pump Equipment,and 3)the U.S.
Department of Energy(DOE)amendment to the Federal test procedure for central air conditioners
and heat pumps.
NEEA's Low Load Efficiency(LLE) laboratory research study was concluded,with six units tested in
UL labs over the summer of 2024,followed by a physical"tear down"of units to help identify the
mechanical source of LLE savings.These efforts actively engaged a broad spectrum of
manufacturers,with the project receiving donated heat pumps from several manufacturers,along
with manufacturer staff time to commission products on site.To fully leverage recent studies,
NEEA has initiated updated field and lab data analysis and energy modeling to refine estimates of
savings rates for advanced heat pump improvements.A Request for Proposals was launched in
2024 for this effort.
In December, NEEA kicked off a new collaboration of technical experts,two national laboratories
and manufacturers to build consensus on a new heat pump connected commissioning
specification. NEEA expects to report savings from this program in 2025/2026.
Commercial Lighting
NEEA engages commercial lighting manufacturers and their supply chain to enhance promotion
and luminaire level lighting controls sales in the Northwest. In 2024, NEEA added a manufacturer
to the program that serves Montana and Idaho territories. Including these sales made a significant
difference to total observed sales. NEEA works with manufacturers by partnering with
manufacturer representatives to educate lighting specifiers, lighting engineers and installers the
capabilities and value of luminaire level lighting controls. Recently, NEEA influenced the
Illuminating Engineering Society's Lighting Practice committee to add these controls to its
Recommended Practice standards. Many lighting designers and building managers reference this
standard when making lighting decisions.
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2024 Idaho Annual Conservation Report Appendices

New Construction
NEEA's efforts support and encourage innovation within the supply chain and inform voluntary
specifications and codes ensuring that consumers and building owners have choices/options for
products that are proven to perform well and save energy. In 2024,NEEA started a code
compliance evaluation for Idaho commercial code.The study assesses the path(s)by which and
degree to which code compliance is achieved with the amended 2018 International Energy
Conservation Code(IECC)in newly constructed buildings and measures the energy performance of
a subset of these buildings as compared with the average energy performance of buildings
constructed under previous code.The results of the analysis and studies will inform NEEA's market
intervention strategies for new construction including its training and education programs.
Emerging Technology
NEEA aggregates and leverages the power of the region,creating economies of scale to identify
and vet emerging technologies,bringing forward new products that are proven to perform well
and save energy.Two major products saw ENERGY STAR specification changes in 2024:Air Source
Heat Pumps and Room Air Conditioners. NEEA provided support and suggestions for ENERGY STAR
to amend the Air Source Heat Pump specification,increasing the performance stringency to
achieve ENERGY STAR Most Efficient performance levels,which went into effect on December 4.
NEEA also provided feedback to ENERGY STAR in developing a test method for room air
conditioners with heat pump heating modes.This update went into effect in November and more
accurately captures the energy efficiency benefits of the emerging category of room heat pumps.
Additionally, ENERGY STAR began revisions of the Residential Clothes Dryer Specification,in which
NEEA provided substantial feedback and data from its numerous laundry efforts, including heat
pump dryer testing,field laundry research,and laundry pair testing. Increasing the availability of
high-performing efficient technologies in the market gives customers more and better options
when it comes to the products and technologies they can purchase.
Building Stock Assessments
NEEA has five regional studies that hit milestones in 2024.The 2022 Residential Building Stock
Assessment was completed,and the study's final report and datasets were posted to neea.org.
The design phase of the 2025 Commercial Building Stock Assessment finished and the study began
collecting data through commercial building site visits.The Home Energy Metering Study and
Commercial Energy Metering Studies both completed their metering installations and continue to
capture metering data on hundreds of buildings. Last, NEEA began designing a new study on
motor-driven system characteristics named the 2027 Motor-Systems Stock Assessment.
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2024 Idaho Annual Conservation Report Appendices

Market Data and Research
NEEA's Market Research and Evaluation team managed nearly 40 third-party research and
evaluation studies to support alliance Market Transformation programs.Seven program market
progress evaluations launched or concluded in 2024, including Manufactured Homes, Retail
Product Portfolio, Extended Motor Products,Commercial and Residential Building Codes,
Luminaire Level Lighting Controls,and two Commercial HVAC programs.These mixed method,
longitudinal evaluations are instrumental to understanding the market opportunity for these
measures,as well as for tracking NEEA's progress toward its Market Transformation goals.These
evaluations together with several market research studies exploring emerging market
transformation program themes including consumer use and attitudes toward connected
consumer products and the market for agricultural pumps,can deliver high-value and actionable
market intelligence for Avista Utilities going forward.
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2024 Idaho Annual Conservation Report Appendices

Appendix A
Allocation Methodology
Avista Utilities Idaho requested that NEEA use a service territory allocation approach where
possible starting in 2023. NEEA uses the best available data to estimate these shares. More details
about the allocation approaches by program is available on the Service Territory Shares worksheet
of the attached spreadsheet.
Baseline and Technical Assumptions
This report follows NEEA's method of measuring electric energy savings from market
transformation efforts. The baseline is an estimate of the market adoption for the region without
intervention by NEEA,the Bonneville Power Administration,the Energy Trust of Oregon,and
utilities and its partners. Prior to reporting the savings above the baseline, NEEA removes the
savings counted through the local programs.This effort avoids double counting energy savings.
The technical assumptions come from third-party research including NEEA-contracted research
and the Regional Technical Forum.
More details about the assumptions are available here:
neea.org
Go to the Portal Login-->Savings Reports
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2024 Idaho Annual Conservation Report Appendices

APPENDIX G - NEEA 2024 ANNUAL SAVINGS REPORT - NATURAL GAS
Memorandum �>
March 27, 2025 neea
TO: Nicole Hydzik, Director of Energy Efficiency,Avista Utilities; Meghan Pinch,Manager
of Program Managers,Avista Utilities; Kim Boynton, Manager of Planning and
Analytics,Avista Utilities
CC: Becky Walker,Chief Program Officer;Stephanie Rider; Director Portfolio
Management, Data Strategy and External Reporting, Nathan Martinez, Director,
Market Analytics, Research and Evaluation;Virginia Mersereau,Vice President of
Corporate Strategy and Communications
FROM: Christina Steinhoff, Principal Planning Analyst, NEEA
SUBJECT: Final 2024 Annual Natural Gas Savings Report
................................................................................
NEEA is an alliance of utilities and energy efficiency organizations that pools resources and shares
risks to transform markets toward energy efficiency that benefits consumers and businesses in the
Northwest. At its heart, NEEA is a collaborative organization that works with all parts of the
market to enable efficient technology choices for consumers:gathering and analyzing data to
inform both regional power planning and utility programs,leveraging its relationships with mid
and upstream market actors like manufactures and retailers,and improving how products are
tested and perform in real life applications.Activities include:
• Providing data and insights to understand how the market is responding to the technology
solutions to inform resource planning and identify new opportunities and product options
for energy efficiency.
• Providing Avista Utilities Idaho with an up-to-date,neutral,and representative
characterization of existing Northwest building stock and energy trends,which inform
market transformation programs and identify opportunities for private sector investment.
• Leveraging trusted relationships with the supply chain to share insights on how well new
technologies perform,save energy,and reduce waste.
• Aggregating and leveraging the power of the region to identify and vet emerging
technologies and then create the market conditions necessary for them to take hold.The
alliance also helps the regional capture natural gas energy savings through these voluntary
interventions and by informing codes and standards that represent consumer and business
needs.
NEEA is currently building its portfolio for natural gas energy efficiency programs.
2024 Idaho Annual Conservation Report Appendices

This memo provides more information about:
1. 2024 savings estimate based on the early market transformation work of NEEA in
commercial and residential new construction as well as its new Efficient Rooftop Units
program.
2. Regional Gas Portfolio Update highlighting work NEEA completed in 2024 to build out the
gas portfolio.
Please contact Christina Steinhoff at [e-mail] with any questions about this report.
2024 Savings Estimate
NEEA estimates Avista Utilities' Idaho 2024 annual natural gas energy savings associated with its
initiatives is 285,431 Annual Therms'(Table 1).The Efficient Rooftop Units program is still in early
market development;so,no savings above baseline were tracked. Residential values are above a
natural market baseline and allocated based on service territory shares(Appendix A).
Table 1:2024 Annual Report Net Market Effects Savings*Estimates(Annual Therms)
•
Efficient Rooftop Units" -
Residential 285,431
New Construction(Codes) 285,431
*Net Market Effects=Total Regional Savings-Local Program Savings-Baseline Savings
**The Efficient Rooftop Units program is early in NEEA's Market Development phase(Appendix B),resulting is limited savings
above the natural market baseline.Savings will increase and the program's market influence increases.
Regional Gas Portfolio Update
NEEA is developing and advancing new energy efficiency measures to add to its savings portfolio.
Annual gas savings will increase over time as programs in the portfolio advance into full-scale
market development(Appendix B).Table 2 lists NEEA's expectations for gas savings.The following
section provides more detail about the progress toward meeting these goals.
'The term Annual Therms refers to the fact that NEEA reports first-year savings only in order to represent a sustained reduction in
load.
z NEEA estimates Baseline as the savings that would have occurred without NEEA,utility,and the Energy Trust of Oregon's market
intervention.
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2024 Idaho Annual Conservation Report Appendices

Table 2:Savings Expectations
Commercial New Inform future codes in NEEA's efforts support and encourage innovation within
Construction Idaho the supply chain and inform voluntary specifications and
Residential New Specific proposals codes ensuring that consumers and building owners have
Construction advanced in 2018 choices/options for products that are proven to perform
International well and save energy.In 2024,NEEA started a code
Conservation Code in compliance evaluation for Idaho commercial code.The
Idaho&future codes results of the analysis and studies will inform NEEA's
market intervention strategies for new construction
including its training and education programs.
Efficient Rooftop Efficient Rooftop Units The program accelerates the adoption of efficient gas
Units(ERTU) (ERTU) rooftop units in the like-for-like replacement market while
working to influence the adoption of improved test
procedures.NEEA is reporting savings from this program.
In 2024,NEEA updated the specification to emphasize a
fuel-neutral approach focusing on ERTU cabinet design and
shell measures. This adjustment should help to gain better
attention in the supply chain to secure commitments to
this product and increase speed of market adoption
Standards Commercial Kitchen NEEA compiles critical market data and insights that inform
Equipment(WA) voluntary local,state,and federal standards.No additional
savings from newstandards occurred in 2024.
Advanced Gas Heat Pump Water The program moved into the Program Development stage
Commercial Heaters of NEEA's Initiative Lifecycle(Appendix B)and is investing
Water Heating in research and field demonstrations that will inform
market transformation strategy while validating the
product performance and energy savings.NEEA will report
any savings from field demonstration projects in 2025,
with additional savings starting as early as 2026.
Gas High- Gas High-efficiency This program will focus on transforming the market for
efficiency Dedicated Outdoor Air commercial gas hydronic systems.Due to the ability to
Dedicated Systems(DOAS) build off the market relationships and progress made by
Outdoor Air the existing Very High Efficiency(VHE)DOAS program in
Systems(DOAS) the electric portfolio,NEEA is expecting to propose this
program for advancement directly into the Market
Development phase of the Lifecycle(Appendix B)in 2025.
Residential Dual- Dual-fuel system with This program will be brought forward for consideration to
fuel Heating a heat pump and gas advance to the Program Development phase of the
Ventilation and furnace with Initiative Lifecycle(Appendix B)in Q3 2025.
Air Conditioning controller
(HVAC)
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2024 Idaho Annual Conservation Report Appendices

Efficient Rooftop Units
The Efficient Rooftop Units program advanced to Market Development3 in late 2022.The
program's goal is to accelerate the adoption of efficient gas rooftop units in the like-for-like
replacement market while working to influence the adoption of improved test procedures and
more stringent federal standards.
In 2024,the program updated its measure specification to emphasize a fuel-neutral approach that
focuses on the rooftop unit cabinet design and shell measures-cabinet insulation, low-leakage
dampers,and heating/energy recovery.This new specification aligns with how builders select
rooftop units where the heating type provided is an option after choosing product line and feature
sets.The program made the change to enhance NEEA and partner influence to increase adoption
of the most efficient options.
The program also worked to encourage manufacturers to develop and promote efficient rooftop
units for the light commercial market. In 2024,one light commercial manufacturer designed and
worked to bring an energy recovery ventilator product to market for use in their light commercial
rooftop units.The manufacturer started production on initial products. NEEA continues to vet and
support development of additional product lines to expand qualified choices to customers and
drive down costs of efficient options.
Finally,the program completed a performance monitoring study for two efficient rooftop units
installed in Portland in 2023.The study found that the efficient rooftop unit features contributed
to the expected efficiency/energy savings,though it highlighted cost and compatibility barriers
that need to be addressed to reach the like-for-like replacement market.
To measure savings, NEEA collects sales data annually from HVAC distributors and manufacturers
in addition to data from the annual local utility program survey. NEEA is working to recruit
additional distributors and manufacturer reps to gain a better view into efficient unit sales and
expects improvement in market insight overtime.
3 The purpose of this phase is to create lasting market change through direct market interventions designed to remove
barriers,leverage market opportunities and tap influencers and existing channels for diffusion.Interventions are strategic,
planned and adaptively managed as market dynamics change and more information is gained.During annual planning,
NEEA staff look for the most impactful market levers and activities that could bolster or accelerate the achievement of
alliance MT goals.
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2024 Idaho Annual Conservation Report Appendices

Advanced Commercial Water Heating
NEEA's Advanced Commercial Water Heating program centers on utilizing gas heat pumps as the
primary heat source in commercial central water heating systems.A gas heat pump functions by
transferring heat from one area to another while intensifying the heat during this process. NEEA
anticipates the technology will enable water heating applications to achieve efficiencies of greater
than 1.0 Thermal Efficiency and hold the technical potential to save the Northwest region more
than 22 million Therms over a 20-year projection.
NEEA completed market research in 2024 indicating that most decision makers see gas heat
pumps as an exciting new option and are impressed with their features,such as good return on
investment and low operating costs.4 Findings from the research will inform NEEA's market
transformation program planning and help identify key target markets for possible inclusion in
future program efforts.
During 2025, NEEA is launching a North American Commercial Gas Hater Heating Market
characterization funded by the North American Gas Heat Pump Collaborative and led by NEEA and
is in the screening and selection process for 2 sites for field demonstrations of the technology.
Gas High-Efficiency Dedicated Outdoor Air Systems
NEEA's goal is to build a portfolio of the most impactful market transformation opportunities for
HVAC systems across gas and electric technologies/practices. In 2024, NEEA started a plan to add
a gas option to its Very High Efficiency Dedicated Outdoor Air System specification and
program. The addition will allow NEEA to more swiftly transform the commercial market through
broader market engagement and demand creation. NEEA expects to publish the first Market
Progress and Evaluation report for the program in 2025.
Residential Dual-Fuel HVAC
This program is currently in the Concept Assessment phase of the Initiative Lifecycle(Appendix B).
The solution would pair a heat pump with a gas furnace to deliver an efficient combined HVAC
system. To date, NEEA has partnered on multiple dual-fuel modeling,lab and field-testing projects
in addition to convening regional stakeholders to share information about the pilot projects
underway. NEEA is expecting to build off these findings to bring forward a proposal to advance to
the Program Development Phase in 2025.
°Lieberman Research.2025.Market Research on Existing Water Heater in Select Commercial Buildings.
Northwest Energy Efficiency Alliance
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2024 Idaho Annual Conservation Report Appendices

Efficient Residential Gas Water Heaters
In 2024, NEEA responded to policy directives in Washington by evolving the Natural Gas Market
Transformation Portfolio to prioritize dual-fuel,fuel neutral,and commercial opportunities
relevant to all funders. Because of this,as well as market headwinds that these products have
been experiencing, NEEA is winding down activities in Efficient Residential Gas Water Heating.
NEEA will continue engagement with North American Gas Heat Pump Collaborative,other utilities,
and industry groups as a part of scanning to track the commercialization and market response to
this product and its viability for inclusion in future building codes or product standards.
Northwest Energy Efficiency Alliance
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2024 Idaho Annual Conservation Report Appendices

Appendix A: Methodology to Forecast Savings
Allocation Methodology
NEEA allocates code savings for gas measures using a state/service territory approach (Table 3).
The approach uses EIA residential consumer sales for Residential Codes and nonresidential volume
for Commercial Codes.
Table 3:State Code Savings Allocation Share
Sector WA OR ID
Residential 0.00% 0.00% 18.33%
Commercial 0.00% 0.00% 15.38%
NEEA used service territory allocations for the Efficient Rooftop Units savings because the program
is new to the market and is tracking installations by service territory.
Baseline, Local Programs and Technical Assumptions
This report follows NEEA's method of measuring gas energy savings from market transformation
efforts. The baseline is an estimate of market adoption without intervention by NEEA, Energy
Trust of Oregon and utilities. Prior to reporting the savings above the baseline, NEEA removes the
savings counted through the local programs.This effort helps funders avoid double counting
energy savings.
The technical assumptions come from third-party research including NEEA contracted research
and the Regional Technical Forum. Details are available within the spreadsheet accompanying this
memo.
Northwest Energy Efficiency Alliance
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503.688.5400 1 Fax [phone] Page 7 of 8
2024 Idaho Annual Conservation Report Appendices

Appendix B: Initiative Life Cycle
NEEA has a robust stage-gate process for managing its programs called the "initiative lifecycle".
The ILC provides a set of core business processes&tools that ensure standardized management of
investment,risk and best practices. Figure 1 shows how initiatives move through the cycle(from
left to right)as NEEA learns more about their promise and potential for the region,the barriers
preventing that promise from being achieved,and ways to leverage the power of the region to
remove those barriers.The end of each phase is marked by a formal management review called a
milestone. NEEA formally solicits approval from Natural Gas Advisory Committees at key program
milestones.
Figure 1:Initiative Lifecycle
concept development program development market transformation
+ d d
Advisory Covumdtee Vote. Adrrsmy CanmNee Vole: Advisory Committee Vote:
Concept Advancement Program Advaneemenr rransRron to Momformt
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2024 Idaho Annual Conservation Report Appendices

APPENDIX H - IDAHO FURNACE BILLING ANALYSIS MEMORANDUM
Avista Idaho Furnace Billing Analysis Memorandum
7/14/2025
Introduction
ADM Associates(ADM)conducted a billing analysis to assess the natural gas savings associated
with Avista Utilities'(Avista)Idaho gas furnace program participants from 2022 through 2024.As
detailed below,ADM tested a variety of diJerent data cleaning scenarios and regression models,
but ultimately the analysis ADM selected suggested that furnace installation in Avista's Idaho
service territory was associated with annual gas savings of 80.6 therms or 10.3%of average annual
gas usage.This memorandum provides an outline of ADM's methodology,details scenarios tested,
and presents final savings results.
Avista shared raw data with ADM that contained monthly bills from August 2021 through June 2025
for 9,105 customers installing gas furnaces between 2022 and 2025.After reviewing the raw data,
ADM conducted a billing analysis that can be split into three components,standard data
preprocessing,cleaning scenario testing,and regression analyses.
Standard Data Preprocessing
ADM follows a standard data preprocessing pipeline to ensure that only relevant customers with
suJicient data are included in analyses.In the case of this analysis,preprocessing included the
following steps:
1. Identify any customers in both the midstream and downstream billing datasets and assign
them to only one.355 customers in both datasets were removed from the downstream and
included in the midstream dataset.
2. Remove customers who participated in other energy eJiciency programs during the
analysis period,this decreased the billing data customer count from—9,100 to—6,100.
3. Remove customers who installed furnaces prior to 2022 or after 2024,these customers will
inevitably have insuJicient billing data for analysis.
4. Filter billing data to only include gas usage.While filtering billing data ADM identified 89
customers who had bills with nearly identical usage for a given billing period,so an average
of those bills was taken.
5. Calendarize billing data and remove any customers with>1 day diJerence in total billed
duration after calendarization.l
6. Remove bills with<24 billed days or>31 billed days.Each billed month included in ADM's
analysis should be representative of nearly all if not all days of a month.
Calendarization is a process by which raw customer bills are aggregated into clean monthly buckets.
2024 Idaho Annual Conservation Report Appendices

7. Add heating degree day(HDD)and cooling degree day(CDD)weather data to billing data.
ADM sources weather data from the National Oceanic and Atmospheric Administration's
(NOAA)Global Hourly Integrated Surface Database.'Weather data from the closest
available weather station to each customer zip code was used. HDD and CDD calculations
assumed a 65°F setpoint.
8. Remove customers who had>1 furnace installed based on available tracking data.While
some of these customers could have suJicient billing data for analysis,ADM avoided
potential confounding factors by excluding them.
9. Subset billing data to only include 12 months prior to and 12 months after furnace
installation for each customer(i.e.,12 months of pre period and 12 months of post-period
data).
Cleaning Scenario Testing
After running these nine data preprocessing steps,ADM then tested a variety of data cleaning
scenarios and regression models.The data cleaning scenarios ADM tested involved varying the
following five variables:
■ Number of pre-period months of billing data required (e.g., 8, 10, or 12)
■ Number of post-period months of billing data required (e.g., 8, 10, or 12)
■ Customer track(e.g.,downstream,midstream,or both)
■ Customer state(e.g.,ID,WA,or both)
■ Customer furnace installation year(e.g.,2022,2023,2024,or all years)
Ultimately,ADM selected the following data cleaning scenario.To be included in the final regression
analysis,customers had to have at least 10 months of pre-period and post-period billing data,
could be a part of either track,and had to reside in Idaho.Within these parameters,ADM assessed
savings results by furnace installation year and across all years combined.
Regression Analysis
ADM tested six diJerent regression models but selected the following one since it maximized
adjusted R-squared across all cleaning scenarios and included both temporal and weather
controls.
Equation 0-1.Fixed Effect Pre/Post Regression Model Specification
AAAAAAp =aaq+PPg(PPPPPPPP) +PPa1o(HHAAAA)!'+flQ&(PPPPPPPP x HHAAAA)p"+PP.(MMPR(,fh)-,
+flg((AACCPPPPPPCCCCCC AACCC(CCDD)!+EE,��
https://www.ncei.noaa.gov/data/global-hourly
2024 Idaho Annual Conservation Report Appendices

Where:
■ i=the ith household
■ t=the first,second,third,etc.month of the analysis period
■ AAAAAAr=Average daily gas usage in month t for household i
■ PPPPPPPP,,,=A dummy variable indicating pre-or post-period designation during period t
at facility i
■ HHAAAAr.=Average heating degree days during period t at the nearest weather station to
household i
■ MMPPMMPPh..=A categorical variable indicating the month during period t
■ AACCPPPPPPCCCCCC AACCCCCCDD,=a customer-specific dummy variable isolating individual household
eJ ects
■ esr-=The error term
■ aay=The model intercept
■ ##$)(=Coe.licients determined via regression
Results and Conclusions
Results of this regression analysis by measure installation year and across all three years are
presented below.
Table 1.Idaho Furnace Billing Analysis Results
Year Customers Included Estimated Annual Percentage p-value
in Analysis Savings(therms) Savings
2022 43 58.59 7.01% 0.010
2023 491 75.66 9.50% 0.000
2024 337 90.00 11.81% 0.000
All(2022-2024) 871 80.58 10.26% 0.000
This billing analysis suggests that between 2022 and 2024,gas furnaces installed in Idaho and
rebated by Avista were associated with savings of 80.6 therms annually.These savings were
statistically significant at the 0.05 alpha,as were the savings for all years assessed individually.
From 2022 to 2024,estimated savings seem to have steadily increased from 58.6 therms in 2022 to
75.7 therms in 2023 to 90.0 therms in 2024.
It is unclear exactly why estimated savings were substantially lower in 2022 than in 2024,but the
small sample size of 43 customers in 2022 is likely a contributing factor.With only 43 customers
included in that analysis,if a few of them took winter vacations in the pre-period(after not travelling
during the COVID-19 pandemic)or had increased occupancy in the post-period,that could have
contributed to decreased estimated savings. Furthermore,diJerences in baseline Annual Fuel
Utilization EJiciency(AFUE)for customers installing furnaces in 2022 as compared to other years
could have contributed to decreased estimated savings.While Avista does not track baseline
2024 Idaho Annual Conservation Report Appendices

furnace AFUE(i.e.,the eJiciency of furnaces being replaced)customers in 2022 might have had
baseline furnaces with higher AFUEs than customers in 2023 or 2024. It is likely that some
combination of these factors contributed to the 2022 furnace billing analysis yielding estimated
savings of 58.6 therms.
An assessment of customer household geography did not reveal any dramatic diJerences by year.
Across 2022,2023,and 2024 most customers installing furnaces resided near Coeur d'Alene.
Similarly,an analysis of Regional Technical Forum (RTF) Heating Zone distribution by year did not
reveal dramatic diJerences in customer Heating Zone assignment.Collectively this indicates that
geography is likely not the main cause of diJerences in furnace savings estimates by year.ADM also
assessed the average eJicient AFUE(i.e.,the eJiciency of newly installed furnaces)and did not
identify any major diJerences by year.Customers in 2022 had an average eJicient AFUE of 0.956
while customers in 2023 and 2024 had average eJicient AFUEs of 0.957.This diJerence in average
eJicient AFUE by year is small enough that it is unlikely to cause a substantial diJerence in savings.
Ultimately,this analysis suggests that as of 2024,furnace installations by Avista's ID customers
yielded gas savings of 90.0 therms or around 11.8%of average annual gas usage.Furthermore,
eJicient furnaces installed by Avista customers in Idaho between 2022 and 2024 seem to be
associated with savings of 80.6 therms.These annual savings estimates are substantially higher
than the single family household deemed savings estimates between 36.3 and 44.9 therms
included in the RTF Residential Gas Furnace UES workbook v3.1.3 Based on this analysis,in the
future it may be most pragmatic for Avista to calculate furnace gas savings based on a pre vs.post
billing analysis as opposed to either a post-only heating load estimation methodology or a deemed
savings method per RTF data.
3 https:Hrtf.nwcouncil.org/measure/residential-gas-furnaces/
2024 Idaho Annual Conservation Report Appendices

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