20260831Exhibit No. 1 - Avista 2025 Idaho ACR - E.pdf

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Idaho `
2025
Annual �.h
Conservation a
Report
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August 31 , 2026

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.
2

Table of Contents
ExecutiveSummary......................................................................................................................7
IdahoAchievements .....................................................................................................................9
PortfolioTrends...........................................................................................................................9
Expenditures.............................................................................................................................. 11
Cost-Effectiveness...................................................................................................................... 13
ImpactEvaluation...................................................................................................................... 14
TariffRider Balances .................................................................................................................. 16
Commercial/Industrial Sector...................................................................................................... 17
Portfolio Performance................................................................................................................ 17
ImpactEvaluation...................................................................................................................... 18
Cost-Effectiveness..................................................................................................................... 19
Marketing................................................................................................................................... 19
Business Partner Program ........................................................................................................20
Commercial/Industrial Program Summaries ...............................................................................22
Site-Specific Program................................................................................................................22
Prescriptive Lighting Program ...................................................................................................25
Small Business Direct Install Lighting Program.........................................................................27
Commercial/Industrial Prescriptive Non-Lighting Programs......................................................29
Green Motors Rewind Program..............................................................................................29
Commercial Grocer Program..................................................................................................29
Commercial Prescriptive Shell Program.................................................................................30
MidstreamProgram...................................................................................................................32
Building Operator Certification Program....................................................................................34
ResidentialSector.......................................................................................................................35
Portfolio Performance................................................................................................................35
ImpactEvaluation......................................................................................................................36
Cost-Effectiveness.....................................................................................................................36
Marketing...................................................................................................................................37
Residential Program Summaries ................................................................................................39
MidstreamProgram...................................................................................................................39
PrescriptivePrograms ...............................................................................................................41
ENERGY STAR°/NEEM Manufactured Homes Program.......................................................41

Residential Appliances Program ............................................................................................43
Home Insulation Program.......................................................................................................45
Residential Fuel Conversion Program....................................................................................47
Home Energy Audit Program.....................................................................................................49
Low-Income Program..................................................................................................................51
PilotPrograms ............................................................................................................................57
Compressed Air Leak Detection................................................................................................57
Research and Development .......................................................................................................58
Regional Market Transformation.................................................................................................59
Electric Energy Savings Share..................................................................................................59
Natural Gas Energy Savings Share...........................................................................................60
Glossaryof Terms.......................................................................................................................61
Ust of Tables
Table 1 — Energy Efficiency Savings and Cost-Effectiveness Results..........................................8
Table 2 — Idaho Electric Achievements .........................................................................................9
Table 3 — Idaho Natural Gas Achievements..................................................................................9
Table 4 — Energy Efficiency Savings by Sector, Planned vs Achieved — Electric........................ 10
Table 5 — Energy Efficiency Savings by Sector, Planned vs Achieved — Natural Gas ................ 10
Table 6 —Annual Conservation Plan Budget to Actual Expenditures Comparison ..................... 11
Table 7 — Portfolio Cost-Effectiveness Results — Electric............................................................ 13
Table 8 — Portfolio Cost-Effectiveness Results — Natural Gas .................................................... 13
Table 9 —Tariff Rider Activity....................................................................................................... 16
Table 10 — Commercial/Industrial Verified vs Planned Savings — Electric .................................. 18
Table 11 — Commercial/Industrial Verified vs Planned Savings — Natural Gas ........................... 18
Table 12 — Commercial/Industrial Cost-Effectiveness Results — Electric.................................... 19
Table 13 — Commercial/Industrial Cost-Effectiveness Results — Natural Gas............................. 19
Table 14 — Commercial/Industrial Site-Specific Program Metrics ...............................................22
Table 15 — Commercial/Industrial Site-Specific Program Impact Findings — Electric..................24
Table 16 — Commercial/Industrial Site-Specific Program Impact Findings — Natural Gas ..........24
Table 17 — Commercial/Industrial Prescriptive Lighting Program Metrics...................................25
Table 18 — Commercial/Industrial Prescriptive Lighting Program Impact Findings — Electric .....26
Table 19 — Small Business Direct Install Lighting Program Metrics ............................................27
Table 20 — Small Business Direct Install Lighting Program Impact Findings — Electric...............28

Table 21 — Commercial/Industrial Prescriptive Non-Lighting Program Metrics...........................29
Table 22 — Commercial/Industrial Prescriptive Non-Lighting Program Impact Findings — Electric
....................................................................................................................................................31
Table 23 — Commercial/Industrial Prescriptive Non-Lighting Program Impact Findings — Natural
Gas .............................................................................................................................................31
Table 24 — Commercial/Industrial Midstream Program Metrics...................................................32
Table 25 — Commercial/Industrial Midstream Program Impact Findings — Electric.....................33
Table 26 — Commercial/Industrial Midstream Program Impact Findings — Natural Gas..............33
Table 27 — Building Operator Certification Program Metrics.......................................................34
Table 28 — Residential Programs Verified vs Planned Savings — Electric...................................35
Table 29 — Residential Programs Verified vs Planned Savings — Natural Gas ...........................36
Table 30 — Residential Cost-Effectiveness Results — Electric.....................................................36
Table 31 — Residential Cost-Effectiveness Results — Natural Gas..............................................36
Table 32 — Residential Midstream Program Metrics ...................................................................39
Table 33 — Residential Midstream Program Impact Findings — Electric......................................40
Table 34 — Residential Midstream Program Impact Findings — Natural Gas ..............................40
Table 35 — ENERGY STARNNEEM Manufactured Homes Program Metrics .............................41
Table 36 — ENERGY STARNNEEM Manufactured Homes Program Impact Findings — Electric
....................................................................................................................................................42
Table 37 — ENERGY STAR°/NEEM Manufactured Homes Program Impact Findings — Natural
Gas .............................................................................................................................................42
Table 38 — Residential Appliances Program Metrics...................................................................43
Table 39 — Residential Appliances Program Impact Findings — Electric .....................................44
Table 40 — Residential Appliances Program Impact Findings — Natural Gas..............................44
Table 41 — Home Insulation Program Metrics.............................................................................45
Table 42 — Home Insulation Program Impact Findings — Electric ...............................................46
Table 43 — Residential Fuel Conversion Program Metrics..........................................................47
Table 44 — Residential Fuel Conversion Program Impact Findings — Electric.............................48
Table 45 — Home Energy Audit Program Metrics........................................................................49
Table 46 — Home Energy Audit Program Impact Findings — Electric ..........................................50
Table 47 — Home Energy Audit Program Impact Findings — Natural Gas...................................50
Table 48 — Low-Income Program Metrics ...................................................................................52
Table 49 — Low-Income Program Reported Savings ..................................................................53
Table 50 — Low-Income Program Approved Measure List ..........................................................53

Table 51 — Low-Income Program Qualified Rebate Measure List...............................................53
Table 52 — Low-Income Program Cost-Effectiveness Results— Electric ....................................55
Table 53 — Low-Income Program Cost-Effectiveness Results— Natural Gas.............................55
Table 54 — NEEA Energy Savings and Participation Costs.........................................................59
List of Figures
Figure 1 — Electric and Natural Gas Service Areas.......................................................................7
Figure 2 — Commercial/Industrial "Power of Change"Ads..........................................................20
Figure 3 — Residential "Power of Change"Ads...........................................................................38
Figure 4 — Low Income Program Weatherization Flyer...............................................................55
List of Appendices and Supplements
Appendix A— 2025 Electric Impact Evaluation Report
Appendix B — 2025 Natural Gas Impact Evaluation Report
Appendix C —2025 Cost-Effectiveness Tables
Appendix D —2025 Expenditures by Program
Appendix E — 2025 Energy Efficiency Activity by Program
Appendix F — NEEA 2025 Annual Savings Report— Electric
Appendix G — NEEA 2025 Annual Savings Report— Natural Gas
Appendix H — NEEA 2025 Annual Savings Report Addendum
Appendix I — List of 2025 EEAG Meetings and Topics

Executive Summary
For almost five decades, Avista's energy efficiency programs have supported Idaho
customers in finding practical, innovative ways to reduce energy use, improve comfort,
operate businesses more efficiently, and lower energy costs. This 2025 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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In 2025,Avista's Idaho energy efficiency portfolio delivered strong overall savings results,
led by significant electric portfolio performance and continued savings contributions from
natural gas programs. Including regional market transformation savings from the
Northwest Energy Efficiency Alliance (NEEA), total electric savings reached 42,289 MWh,
while total natural gas savings reached 505,591 therms. Electric programs achieved
35,456 MWh, or 200 percent of planned savings, driven primarily by Commercial/
Industrial programs, especially Small Business Direct Install Lighting and Site-Specific
offerings. Natural gas programs achieved 203,384 therms, or 107 percent of planned
savings, with Residential Midstream accounting for the majority of verified gas savings.
Program expenditures exceeded planned budgets for both fuel types, reflecting higher-
than-expected participation, the cost of delivering verified savings, and broader market
conditions affecting customer projects. Electric expenditures totaled approximately $20.7
million compared with a planned budget of $10.6 million, consistent with the portfolio's
substantially higher savings achievement. Natural gas expenditures totaled
approximately $2.7 million compared with a planned budget of $1.8 million, despite
Avista's efforts to manage costs through reduced marketing, targeted program delivery,
and careful screening of participation amid continued cost-effectiveness pressures.
Cost-effectiveness results were mixed. The electric portfolio remained cost-effective,
achieving a Utility Cost Test (UCT) result of 1.40, supported by strong verified savings

from high-volume and cost-effective measures. Conversely, the natural gas portfolio
achieved a UCT of 0.84. Factors affecting natural gas cost-effectiveness included lower-
than-expected verified savings in certain Residential programs, limited participation in the
Site-Specific program, elevated delivery costs relative to avoided gas benefits, and
changes in verification methodologies and documentation requirements.
Impact evaluations reported a 100 percent realization rate for the electric portfolio and a
95 percent realization rate for the natural gas portfolio. From a funding perspective, tariff
rider balances ended the year with a significant electric underfunded balance of
approximately $24.6 million and a natural gas overfunded balance of approximately $2.5
million, resulting in an aggregate underfunded balance of approximately $22.1 million.
Energy efficiency remains one of the company's least-cost resources, and 2025
represented a particularly strong year for conservation, with programs achieving electric
savings well above targets. These results were built on portfolio changes implemented in
2024 that were designed to increase program participation, with additional programmatic
changes made during 2025 as described within this ACR. The table below provides a
summary of Avista's energy efficiency program results for 2025.
Table 1 - Energy Efficiency Savings and Cost-Effectiveness Results
Savings Costs Total Resource Utility Cost
Cost Test
Electric Actuals (kWh) 35,456,276 $20,688,852 1.12 1.40
Percent of Goal 200% 195%
Annual Planned Goal/Budget 17,696,834 $10,594,013
Natural Gas Actuals (Therms) 203,384 $2,742,431 0.64 0.84
Percent of Goal 107% 150%
Annual Planned Goal/Budget 189,434 $1,828,377
Throughout the portfolio, programs continued to prioritize affordability and flexibility while
emphasizing 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 NEEA. Reported energy conservation savings, cost-
effectiveness, and other related data, however, are specific to local programs unless
otherwise noted.

Idaho Achievements
For 2025, savings from NEEA's programs added an additional 6,833 MWh to the
company's electric savings achievements, bringing overall savings achieved from 35,456
MWh to 42,289 MWh. For natural gas, after including 302,207 therms from NEEA's
programs, the overall savings achieved in 2025 was 505,591 therms. The tables below
provide a breakdown of Avista's 2025 savings achievements by program.
Table 2 - Idaho Electric Achievements
Savings Achieved (MWh)
Commercial/Industrial 32,679
Residential 2,635
Low-Income 142
Total Local Program 35,456
NEEA 6,833
Total 42,289
Table 3 - Idaho Natural Gas Achievements
Savings Achieved (Therms)
Commercial/Industrial 31,143
Residential 168,408
Low Income 3,833
Total Local Program 203,384
NEEA 302,207
Total 505,591
Portfolio Trends
In 2025, Avista delivered electric energy savings that substantially exceeded
expectations. The key savings drivers were concentrated in the Commercial/Industrial
portfolio, which accounted for the vast majority of total electric savings. The largest
individual contributors were the Small Business Direct Install Lighting and Site-Specific
programs. The Small Business Direct Install Lighting program's high participation of 1,924
projects and strong verified savings — 18,962,969 kWh with a 102 percent realization rate
— suggest the program effectively reaches customers with common, high-impact lighting
opportunities and delivers savings that closely align with expectations. The direct-install
model also removes common barriers for small businesses, such as limited staff time,
upfront project complexity, and uncertainty about savings, by making participation easy
and accessible. The Site-Specific program was successful in delivering substantial
verified savings of 9,511,607 kWh. The program's custom approach also allowed
evaluators to apply the most appropriate assessment method for each project, helping
capture large, project-specific savings opportunities that standard prescriptive programs
may not address.

Within the Residential portfolio, the Midstream program was the primary savings driver,
contributing more than 84 percent of verified residential portfolio savings. Its success was
supported by collaboration between Avista and its evaluators to review and verify
methodologies, helping ensure reliable savings estimates and strong program
performance. The Midstream program was also bolstered by increased participation in
2025.
Table 4— Energy Efficiency Savings by Sector, Planned vs Achieved -Electric
Planned Savings I Achieved Savings'L�%. of Plan Achieved
Commercial/Industrial 12,890,865 32,678,682 254%
Residential 4,684,420 2,635,482 56%
Low-Income 121,549 142,112 117%
Total 17,696,834 35,456,276 200%
Natural gas programs also delivered substantial therm savings, reaching 107 percent of
the company's planned savings goal. Residential programs drove most verified gas
savings, with the Midstream program contributing more than 87 percent of verified
savings. Significant savings were also achieved through the Residential Shell program
and the Commercial/Industrial Midstream program.
Realization rates were generally strong for 2025 but varied significantly by program.
Some measures and programs underperformed due to methodology and documentation
issues, particularly Appliances, which experienced a 74 percent realization rate, and
Commercial/Industrial Shell, which amounted to 27 percent. Diminishing participation in
gas programs is evident in the relatively small project counts across several program
offerings and the concentration of savings in only a few high-volume programs. The
Residential portfolio had 3,008 gas projects, but most activity was concentrated in
Midstream, which accounted for 1,891 projects. Commercial/Industrial programs
accounted for 83 total projects, of which 79 were Midstream.
Table 5 - Energy-Efficiency Savings by Sector, Planned vs Achieved—Natural Gas
Planned Savings Achieved Savings % of Plan Achieved
(Therms) (Therms)
Commercial/Industrial 28,130 31,143 111%
Residential 157,066 168,408 107%
Low-Income 4,239 3,833 90%
Total 189,434 203,384 107%
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Expenditures
As part of Avista's annual business planning process, the company sets an expectation
to pursue all cost-effective measures possible. Because of this mandate, variances may
exist between planned and actual spending each year. In 2025, expenditures forAvista's
conservation programs significantly exceeded planned budgets for both fuel types. In the
electric portfolio, actual spending was approximately twice the planned amount,
consistent with achieving 200 percent of planned kWh savings. In the natural gas
portfolio, actual spending reached approximately 150 percent of the planned amount,
while savings achieved 107 percent of planned therm savings.
Overall, Avista experienced higher-than-expected expenditures across nearly every
category, driven primarily by the level and mix of customer participation, the cost of
delivering verified savings, and broader market conditions affecting customer projects.
Electric incentives increased from approximately $6.2 million planned to $15.8 million
spent, and natural gas incentives, which increased from approximately $1.2 million
planned to $1.8 million spent. Higher electric incentive expenditures are primarily
attributed to the actual participation and savings achievements substantially exceeding
what was planned, particularly in high-volume and high-performing programs such as the
Small Business Lighting and Commercial/Industrial Site-Specific programs. Higher
natural gas incentive expenditures were the result of the Residential Midstream and Low-
Income programs.
The table below provides a detailed comparison of budgeted to actual energy efficiency
expenditures by fuel type.
Table 6 -Annual Conservation Plan Budget to Actual Expenditures Comparison
2025 Planned Expenses 2025
2025 Electric Planned vs Actual Expenses
Incentives $6,152,749 $15,777,768
Non-Incentives and Labor $3,213,619 $3,769,799
MT, CPA, EM&V $1,227,644 $1,141,285
Total Expenditures $10,594,013 $20,688,852
Incentives $1,176,065 $1,815,377
Non-Incentives and Labor $348,735 $446,912
MT, CPA, EM&V $303,577 $480,143
Total Expenditures $1,828,377 $2,742,431
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For the natural gas portfolio, Avista took a targeted approach to reducing expenditures
where possible in response to continuing cost-effectiveness pressures.' The company
implemented a variety of cost controls throughout 2025, including reducing marketing and
broad outreach activities, narrowing program delivery to a more limited set of offerings,
and continuing to screen and manage participation with cost-effectiveness considerations
in mind. Despite these efforts, natural gas expenditures exceeded the planned budget
because completed projects and customer participation were concentrated in measures
and programs that required incentives, technical review, implementation support, and
measurement and verification activities to produce verified savings.
Even with the more constrained natural gas portfolio and active efforts to limit
discretionary implementation activities, costs supporting natural gas programs continued
at an elevated pace as Avista achieved 107 percent of its planned therm savings.
Incentive costs increased as eligible customer projects were completed and paid in
accordance with program requirements, while non-incentive costs reflected the technical
and administrative effort necessary to support program administration, project review,
evaluator coordination, and compliance activities. These costs do not always decline in
direct proportion to participation levels, particularly when savings are concentrated in in
a smaller number of measures or when custom and midstream offerings continue to
require substantial administrative oversight.
External market conditions also likely contributed to higher project costs across both
sectors. While supply chain disruptions that affected the market from 2020 through 2023
continued to ease, commercial and industrial customers still faced elevated equipment
and project costs, labor costs, contractor availability constraints, tariff-related uncertainty,
and higher borrowing costs. These factors increased the cost of completed efficiency
projects and may have influenced the number, timing, and type of projects completed
during the year. Some customers decided to move forward on larger or higher-savings
projects that had strong economic or significant savings potential, while others may have
delayed or deferred smaller opportunities. Taken together, the 2025 cost increases reflect
strong electric portfolio performance, necessary delivery costs for verified savings, and
market conditions outside of Avista's direct control.
As described within Avista's Application to temporarily suspend its natural gas demand side management
(DSM) programs in Case No.AVU-G-26-01 and noted cost-effectiveness pressures within the natural gas
portfolio are attributed to declining avoided cost values, increasing program delivery costs,and the resulting
challenge of maintaining portfolio cost-effectiveness while continuing to acquire cost-effective therm
savings.
12

Cost-Effectiveness
Avista evaluates its energy efficiency portfolio throughout implementation and again at
the end of each program year to assess cost-effectiveness. These tests help determine
whether programs provide value from both the company and customer perspectives. For
the electric and natural gas portfolios, Avista's cost-effectiveness target is a UCT result
greater than 1.00, indicating that utility benefits exceed the costs of program delivery.
Table 7 - Portfolio Cost-Effectiveness Results—Electric
Cost-Effectiveness Test J Benefits Benefit/Cost Ratil
Utility Cost Test(UCT) $26,734,655 $19,039,212 1.40
Total Resource Cost(TRC) $26,734,655 $23,820,458 1.12
Participant Cost Test (PCT) $42,092,287 $20,138,877 2.09
Ratepayer Impact (RIM) $26,734,655 $21,535,882 1.24
The electric portfolio's UCT of 1.40 was primarily attributed to strong verified savings from
high-volume programs, particularly Lighting and Midstream, where realization rates were
close to or slightly above 100 percent. While some smaller programs produced lower
realization rates, their impact was outweighed by the larger savings contributions from
cost-effective measures across the portfolio.
Table 8 - Portfolio Cost-Effectiveness Results— Natural Gas
Cost-Effectiveness Test Benefit/Cost Ratio
Utility Cost Test(UCT) $1,892,976 $2,254,067 0.84
Total Resource Cost(TRC) $1,892,976 $2,937,888 0.64
Participant Cost Test(PCT) $3,700,568 $2,491,413 1.49
Ratepayer Impact(RIM) $1,892,976 $2,372,664 0.80
As further described in Avista's request to suspend its natural gas demand side
management (DSM) programs (the "Suspension Application") in Case No.AVU-G-26-01,2
the company developed a portfolio for the 2025 program year that was cost-effective
under then-current planning assumptions, although only marginally so. In the end,
however, lower-than-expected verified gas savings in several Residential programs and
program costs that were high relative to avoided natural gas benefits ultimately limited
the company's ability to maintain portfolio cost effectiveness. As a result, the 2025 natural
gas portfolio achieved a UCT of 0.84.
One example of lower-than-expected verified savings involved natural gas furnaces.
While Avista had hoped to better stabilize the tight cost-effectiveness margins of its 2025
2 Application to Suspend Natural Gas Demand-Side Management Programs, Case No. AVU-G-26-01,
Idaho Public Utilities Commission, available at IPUC Filing.

portfolio through the use of billing analysis methods to estimate furnace savings, rather
than relying solely on Regional Technical Forum (RTF) baselines, the Company ultimately
moved away from that methodology in response to PUC Staff comments regarding the
validity of that methodology for planning purposes.3 Consequently, verified therm savings
within the Residential Midstream program were lower than expected, reducing portfolio
benefits included in the UCT calculation, while program costs remained largely
unchanged. This placed downward pressure on cost-effectiveness.
Limited customer participation, particularly within the Site-Specific program, also
contributed to reduced portfolio cost-effectiveness. The program, which typically delivers
significant custom commercial and industrial savings opportunities, completed only two
natural gas projects during 2025, generating 2,838 verified therms of savings and $10,508
in incentive payments.Although these projects achieved a 95 percent realization rate and
generally performed as expected, the low participation level limited the program's
contribution to overall portfolio savings. As a result, fewer therm savings were available
to offset ongoing administrative, implementation, and evaluation costs, reducing the
overall benefits reflected in the UCT. While the individual projects performed well, the
project pipeline was insufficient to meaningfully improve portfolio-level cost-effectiveness.
Finally, more granular RTF verification methodologies reduced savings for certain
measures relative to planning assumptions, and some claimed measures did not meet
required documentation or efficiency standards. Although several programs performed
well, including Residential Midstream and most Commercial and Industrial offerings,
those results were insufficient to offset lower realization rates and the broader cost-
effectiveness pressures affecting the natural gas portfolio.
Throughout the year, the company regularly engaged with Idaho Public Utilities
Commission (IPUC) staff and its Energy Efficiency Advisory Group (EEAG) regarding
concerns about the natural gas portfolio's cost effectiveness.4 Avista provided updates on
program performance, discussed factors contributing to declining cost-effectiveness, and
highlighted the importance of strong participation in the Site-Specific program to support
overall portfolio results.
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: 100 percent realization rate and 35,456,276 kWh in annual verified
savings.
s Case No.AVU-G-25-09, Order No. 36975.
a The cost effectiveness of the Idaho natural gas portfolio was discussed at both the March 4 and June 25,
2025, EEAG meetings, in addition to multiple meetings with IPUC staff.
14

Natural Gas: 95 percent realization rate and 203,384 therms in annual gross
savings.
Impact evaluations were completed by Avista's contracted third-party evaluator, ADM, a
Qualus Company. See Appendix A for the 2025 Electric Impact Evaluation Report and
Appendix B for the 2025 Natural Gas Impact Evaluation Report.

Tariff Rider Balances
At the beginning of 2025, the aggregate Idaho electric and natural gas tariff rider balance
was underfunded by approximately $6,986,781. During the year, Avista collected
$8,360,174 in tariff rider revenue to support energy efficiency programs and incurred
$23,431,283 in program expenditures. By year-end, the electric portfolio had an
underfunded balance of $24,563,489, while the natural gas portfolio had an overfunded
balance of$2,505,600.
For electric programs, the underfunded balance was primarily influenced by higher-than-
expected participation in the Small Business Direct Install Lighting program, which
resulted in increased program costs. The Prescriptive Lighting program also experienced
participation above forecasted levels, contributing to additional cost increases, though to
a lesser extent than the Small Business Direct Install Lighting program. The
Commercial/Industrial Site-Specific program also contributed to higher incentive costs,
though participation remained generally consistent with initial projections.
The overfunded balance in natural gas programs was primarily attributable to lower-than-
expected participation across both residential and commercial offerings. This reduced
participation was influenced by several factors, including the significant decline in avoided
costs described within this ACR. Participation in the Site-Specific program was especially
limited in 2025, likely due in part to lower avoided costs, which typically result in longer
project payback periods and reduce the economic attractiveness of efficiency
investments.
The table below illustrates 2025 tariff rider activity by fuel type.
Table 9 -Tariff Rider Activity
F Natural Gas Total
Beginning Balance (Underfunded)/Overfunded ($8,792,454) $1,805,673 ($6,986,781)
Energy-Efficiency Funding Collected in 2025 $4,917,816 $3,442,358 $8,360,174
Total Funding Available in 2025 ($3,874,638) $5,248,031 $1,373,393
Energy-Efficiency Expenditures $20,688,852 $2,742,431 $23,431,283
Ending Balances (Underfunded)/Overfunded ($24,563,489) $2,505,600 ($22,057,890)
16

Commercial/Industrial Sector
Avista offers commercial and industrial customers multiple pathways to participate in its
energy efficiency programs. Through the Midstream Program, Avista works with
distributors to increase the availability of energy-efficient HVAC, hot water, and
foodservice equipment for contractors. Prescriptive measures provide a streamlined
option for common improvements, including lighting, building shell upgrades, variable
frequency drives (VFDs), and grocer-related measures. Projects that do not fit within the
Midstream or Prescriptive offerings may be evaluated through the Site-Specific program,
which supports unique or more complex projects requiring custom 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 some cases,
Avista uses a performance-based approach, with incentives paid based on measured
building performance over a multiyear period.
In 2025, Avista also continued its Direct Install Lighting program for small businesses,
providing low- to no-cost lighting upgrades for Schedule 11 and Schedule 12 customers.
The program continued to be well received by both customers and trade allies and
represented more than half of the electric savings achieved during the year. Within the
Commercial/Industrial natural gas portfolio, the Midstream program delivered the majority
of therm savings.
In addition to program offerings, there are several energy efficiency resources available
to Avista's commercial and industrial customers, including the Building Operator
Certification Program, a national training and certification which helps participants
develop skills in commercial building operation, with an emphasis on no-cost and low-
cost solutions. An additional option, Trade Ally Connect, is designed to connect utilities
with certified trade allies—such as contractors, installers, and energy professionals—to
deliver energy-efficient products and services to customers while supporting business
growth for trade allies and energy savings for utilities.
Portfolio Performance
The electric portfolio achieved over 250 percent of its 2025 savings goal, with over half of
the savings coming from the Small Business Direct Install Lighting program. Other high
performers include the Prescriptive Lighting and Site-Specific, all of which achieved at
least double their planned savings goal.
The table on the next page shows savings goals established for Avista's Commercial/
Industrial Programs for 2025, as well as reported savings and percentage of goal
achieved.
17

Table 10 -Commercial/Industrial Verified vs Planned Savings—Electric
Program Planned Sa - Achieved Savings Percentage of
(kWh):n (kWh) Planned Savings
Building Operator Certification - 119,000 N/A
Green Motors - 7,625 N/A
Grocer 30,145 2,919 10%
Commercial/Industrial Midstream 300,329 163,691 55%
Prescriptive Lighting 2,001,191 3,900,750 195%
Small Business Lighting 6,744,200 18,962,969 281%
Commercial/Industrial Shell 15,000 10,121 67%
Site-Specific- Lighting 38,000 91,700 241%
Site-Specific- Other 3,762,000 9,419,907 250%
Total Commercial/Industrial 12,890,865 32,678,682 254%
The Commercial/Industrial Natural Gas Portfolio achieved 111 percent of planned savings
in 2025. The Midstream program exceeded expectations, achieving nearly one-and-a-
half times its planned savings, while the Shell and Site-Specific programs produced lower-
than-expected results. Midstream accounted for 90 percent of Commercial/Industrial
therm savings, with Shell and Site-Specific programs representing the remaining 10
percent.
The table below shows planned savings established for Avista's Commercial/Industrial
Natural Gas programs for 2025, as well as verified savings and percentage of planned
savings achieved.
Table 11 -Commercial/Industrial Verified vs Planned Savings— Natural Gas
Percentage7— Program Planned Savings I Achieved Savings .
(therms) (therms) Planned Savings
Commercial/Industrial Midstream 19,868 28,137 142%
Commercial/Industrial Shell 3,326 169 5%
Site-Specific- Other 4,936 2,838 57%
Total Commercial/Industrial 28,130 31,143 111%
Impact Evaluation
In 2025, the Commercial/Industrial Electric Portfolio reported savings of 32,450 MWh and
achieved evaluated savings of 32,679 MWh, resulting in a realization rate of 101 percent.
The Natural Gas Portfolio reported 31,833 therms and achieved evaluated savings of
31,143 therms, resulting in a 98 percent realization rate (see the program 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 ACR.

Cost-Effectiveness
The two tables below show the Commercial/Industrial Portfolio's cost-effectiveness
results by fuel type.
fable 12 -Commercial/Industrial Cost-Effectiveness Results— Electric
�1llllllllllllllllllECost-Effectiveness Test Benefit/Cost Ratio
Total Resource Cost(TRC) $23,083,221 $18,131,300 1.27
Utility Cost Test (UCT) $23,083,221 $16,337,239 1.41
Participant Cost Test (PCT) $36,707,090 $15,417,930 2.38
Ratepayer Impact(RIM) $23,083,221 $18,638,323 1.24
Table 13 -Commercial/Industrial Cost-Effectiveness Results—Natural Gas
• • • Benefit/Cost Ratio
Total Resource Cost(TRC) $224,764 $440,627 0.51
Utility Cost Test(UCT) $224,764 $288,827 0.78
Participant Cost Test(PCT) $347,746 $274,782 1.27
Ratepayer Impact(RIM) $224,764 $306,987 0.73
Marketing
In 2025, Avista continued a robust, integrated approach to commercial and industrial
energy efficiency marketing, combining relationship-based outreach with expanded digital
and paid media tactics. Marketing efforts focused on increasing awareness of energy
efficiency opportunities and available rebate programs across a broad range of business
types, sizes, and industries.
Business customers were reached through a mix of paid, owned, and earned channels,
including digital and search advertising, streaming and broadcast media, social media,
print advertising, and the Avista website. Regional Account Executives, energy engineers,
and community outreach staff continued to play a central role in building program
awareness and supporting participation through ongoing customer relationships and
project development.
Power of Change
Power of Change was the first large-scale paid social media advertising campaign in
Avista's history. The decision to enter the paid social media market was the result of
changing customer communication preferences and demographics. Ads ran on Meta, X,
Linkedln, TikTok, and YouTube, in addition to digital display and streaming. The
campaign was also leveraged in the company's sponsorship activations at local sporting
events. Ads ran in six-week phases, with a total of six business ads per phase.

The Power of Change campaign continued in 2025 as a component of commercial energy
efficiency marketing. The campaign delivered seasonally relevant, approachable
messaging designed to make energy efficiency more relatable to everyday business
operations. Messaging promoted energy-saving behaviors, rebates and programs, and
was delivered across digital display, search, streaming, social media, and video
platforms, including YouTube. Creative assets were refreshed throughout the year, and
both static and motion ads were used across channels.
Figure 2 -Commercial/Industrial "Power of Change"Ads
�THE t THE
POWER A POWER
OF �OF
TA
.. .
Rebate and program promotion remained a consistent focus throughout the year. Digital
advertising served as the primary paid tactic, supported by print placements in select local
publications. Several commercial programs were also marketed in coordination with third-
party implementers and trade allies, extending the reach of program information and
supporting customer awareness.
Community engagement and sponsorships also supported commercial energy efficiency
awareness in 2025, with messaging integrated into select events, materials, and partner
touchpoints. These efforts reinforced awareness of energy efficiency programs in familiar,
trusted settings. Overall, Avista's 2025 commercial and industrial energy efficiency
marketing efforts emphasized consistent, year-round visibility, alignment with evolving
customer communication preferences, and coordination across customer-facing teams
and paid outreach. These efforts were intended to support broader awareness of Avista's
Idaho commercial and industrial energy efficiency programs.
Business Partner Program
The Business Partner Program (BPP) assists rural small business customers to better
understand and access Avista's energy efficiency resources, including high-level energy
"audits" at no cost to the business owner, budget billing options, and available rebates.
20

Designed as a concierge-style program, BPP provides hands-on support by having the
Program Manager participate in onsite visits when contractors are engaged.
During these visits, customers receive verbal conservation recommendations and written
baseline bids for proposed efficiency measures, giving them clear, practical information
to evaluate potential energy-saving improvements. This personalized approach
strengthens the customer experience and reflects Avista's commitment to delivering
responsive, high-quality service to small businesses. In 2025, six site visits were
conducted in communities including Coeur d'Alene, Wallace, and Kamiah.
Through BPP, Avista continues to offer the Trade Ally Bid program, which connects
customers with qualified vendors such as lighting, HVAC, window, and insulation
providers to develop cost estimates for energy efficiency upgrades. By working closely
with trade ally partners, Avista is able to provide energy assessments, help customers
navigate the efficiency incentive process, and support access to competitive project bids.
This added guidance helps small businesses overcome common barriers, including
limited time, budget constraints, and difficulty accessing contractors, while empowering
them to move forward with meaningful energy efficiency improvements.
21

Commercial/Industrial Program Summaries
Site-Specific Program
Description
The Site-Specific program provides custom incentives for energy efficiency projects that
do not meet the eligibility requirements of Avista's Prescriptive or Midstream
offerings. Incentives are based on verified first-year energy savings, excluding behavioral
changes, and are available for measures with an expected useful life of at least 10 years.
Incentive levels are determined using the simple payback of each individual project.
Avista Account Executives work directly with customers to identify and develop Site-
Specific efficiency opportunities across a variety of applications, including building shell
improvements, lighting upgrades, appliances, compressed air systems, industrial
processes, and non-prescriptive motors. Most projects completed through the program
involve lighting and building shell measures.
As part of the Site-Specific portfolio, Avista also offers a Pay-for-Performance option for
commercial and industrial customers. This performance-based approach rewards
customers for implementing whole-building energy improvements that deliver measurable
reductions in energy consumption at the meter level. Participants receive incentive
payments over a three-year period based on verified energy savings achieved each year,
with payments issued annually at a predetermined incentive rate.
Table 14-Commercial/Industrial Site-Specific Program Metrics
Site-Specific— Electric
Participation, Savings, and Costs
Conservation Projects 15
Overall kWh Savings 9,511,607
Incentive Spend $1,971,896
Non-Incentive Utility Costs $869,613
Idaho Energy-Efficiency Rider Spend $2,841,509
Site-Specific—Gas
Participation, Savings, and Costs
Conservation Projects 2
Overall Therm Savings 2,838
Incentive Spend $10,509
Non-Incentive Utility Costs $12,059
Idaho Energy-Efficiency Rider Spend $22,568
22

Program Activities
The Site-Specific Program continued to deliver strong electric savings in 2025. Projects
in 2025 were generally large, savings-intensive custom projects, particularly within the
non-lighting or "Other" project category. The natural gas Site-Specific program
experienced lower participation and savings in 2025 than expected, achieving only 2,838
therms. Because custom natural gas projects often require technical review and
administrative support regardless of project size, lower project volume can result in higher
non-incentive costs on a per-therm basis. Despite lower than expected savings, the 2025
natural gas impact findings showed a 95 percent realization rate, indicating that
completed projects performed close to expected levels.
Program Changes
No program changes were made in 2025.
Program Marketing
Customer engagement efforts for the Site-Specific and Pay-for-Performance programs
focused on targeted outreach by Avista Account Executives and the Program Manager
to identify and develop energy efficiency opportunities for Avista's commercial
customers. These efforts included participation in chamber of commerce events,
commercial association events, presentations to business and community organizations,
event tabling, and direct customer engagement throughout Avista's service
territory. Program awareness was further expanded through referrals from the Small
Business Partner Program when customer projects were better aligned with Site-Specific
or Pay-for-Performance offerings.
Positive customer experiences and resulting word-of-mouth referrals helped increase
program visibility and encourage participation among local businesses. The Power of
Change business ads were the most widely used and comprehensive business marketing
assets, with consistent placement across digital, social, broadcast, streaming, and
connected TV channels, including high-visibility events such as NFL games and March
Madness. The campaign also appeared regularly in Avista's monthly How's Business
digital newsletter and quarterly in the Spokane Homebuilders Association's Builders
Overview publication, which reaches readers in both Washington and Idaho. In addition,
Avista ran year-round digital and search campaigns promoting specific rebate programs
in Washington and Idaho. Idaho ads targeted Idaho ZIP codes and business customers
and directed customers to rebates for measures such as lighting, insulation, and HVAC.
Together, these outreach and marketing activities supported customer awareness,
engagement, and adoption of energy efficiency improvements.
Impact Evaluation
The tables on the next page show reported and evaluated electric and natural gas savings
for the Site-Specific Program in 2025.

Table 15 -Commercial/Industrial Site-Specific Program Impact Findings—Electric
Program Expected Savings Achieved Savings Realization Rate
Site-Specific- Lighting 101,225 91,700 91%
Site-Specific- Other 9,746,501 9,746,501 100%
Total Site Specific 9,847,726 9,838,201 100%
Table 16 -Commercial/Industrial Site-Specific Program Impact Findings— Natural Gas
Expected Savings Achieved Savings Realization Rate
(therms) (therms)
Site-Specific- Other 3,003 2,838 95%
Recommendations
Evaluators noted that some expected savings methodologies could not be fully reverse
engineered from the available documentation, requiring alternative approaches, such as
billing analysis, to estimate verified savings. To improve future evaluations, it is suggested
that Avista provide the original expected savings Excel calculators or tools whenever
possible, as these would support more complete and accurate verified savings
calculations for complex custom measures. Avista will consider this approach to support
more accurate savings calculations.
Plans for 2026
In 2026, Avista plans to continue offering the Site-Specific and Pay-for-Performance
programs to Idaho electric customers, while discontinuing participation for gas customers
who are not under contract by year-end 2026.
Avista will continue evaluating its measurement and verification processes to identify
opportunities for improvement, strengthen program performance, and support effective
delivery of verified energy savings. The company will also continue offering the Small
Business Partner Program, including the Trade Ally Bid component, as part of its business
customer energy efficiency portfolio.
Avista will support continued participation through targeted customer outreach, proactive
account management, and coordination with trade allies and business partners to
promote program awareness and identify qualifying energy efficiency opportunities.

Prescriptive Lighting Program
Description
The Commercial/Industrial Prescriptive Lighting Program encourages business
customers to upgrade inefficient lighting systems through standardized, per-unit financial
incentives for qualifying measures. The program simplifies participation by offering
pre-determined incentives for common lighting retrofits, supporting the adoption of
high-efficiency LED lighting and advanced controls across Avista's commercial and
industrial customer base.
Table 17 -Commercial/Industrial Prescriptive Lighting Program Metrics
Prescriptive Lighting— Electric
Participation, Savings, and Costs
Conservation Projects 471
Overall Therm Savings 3,900,750
Incentive Spend $835,378
Non-Incentive Utility Costs $323,828
Idaho Energy-Efficiency Rider Spend $1,159,206
Program Activities
In 2025, the Prescriptive Lighting Program continued to provide a stable and efficient
pathway for commercial and industrial customers to pursue cost-effective lighting
upgrades. Inflationary pressures on labor and materials persisted, and Avista maintained
its incentive structure to help offset these costs and support continued customer
participation. As anticipated, overall project throughput remained moderated as eligible
small business customers were increasingly served through the Direct-Install Lighting
Program; however, the Prescriptive Program continued to play an important role in
serving mid-size and larger customers. Program delivery remained steady throughout the
year, supported by ongoing trade ally engagement, Account Executive outreach, and the
expanded use of online tools to streamline customer participation and maintain progress
toward annual savings goals.
Program Changes
Revisions to incentive amounts, measure eligibility, and baseline assumptions, effective
January 1, 2025, were developed through Avista's annual review of market conditions,
energy savings assumptions, and program performance. Advance notice and transition
provisions were provided to customers and trade allies to ensure continuity and clear
understanding of updated program requirements.
Program Marketing
The success of the Prescriptive Lighting Program continues to depend on clear
communication with lighting distributors, electricians, trade allies, and customers
regarding program requirements, incentive opportunities, and application processes.

Marketing efforts in 2025 included maintaining program information on Avista's website,
direct outreach to participating contractors, targeted email communications regarding
program updates, and support from regionally based Account Executives who help
connect commercial and industrial customers with available incentives. Program changes
were communicated through website updates and direct stakeholder communications,
with advance notice provided to allow customers and contractors time to plan and
complete projects under existing program requirements.
Impact Evaluation
The table below shows reported and evaluated electric savings for the Prescriptive
Lighting Program in 2025.
Table 18 -Commercial/Industrial Prescriptive Lighting Program Impact Findings— Electric
Expected Savings Achieved Savings
(kWh) (kWh) Realization Rate
. .
Prescriptive Lighting 3,818,500 3,900,750 102%
Recommendations
The Prescriptive Lighting Program evaluation found a realization rate of 102 percent,
indicating that expected and verified energy savings were closely aligned. Evaluators
recommended that Avista consider applying an in-service rate to expected savings
calculations to account for efficient lighting equipment that may be purchased but not
ultimately installed. Avista acknowledges this recommendation and will consider its
applicability in future program planning; however, given the close alignment between
projected and verified savings, the current methodology continues to provide a
reasonable balance between reporting accuracy and administrative simplicity.
Plans for 2026
Avista will continue to refine and maintain the program to reflect evolving market
conditions, technology availability, and customer needs. Leveraging the measure-level
detail available in iEnergy, the company will review lighting measures and incentive
offerings to ensure they remain aligned with current product performance and market
adoption trends. Avista will also continue evaluating opportunities to incorporate
additional cost-effective lighting technologies into the program where appropriate.

Small Business Direct Install Lighting Program
Description
Small business customers served under rate schedules 11 and 12 are eligible to
participate in the Direct Install Lighting Program, which helps reduce energy use and
improve lighting quality through a complimentary on-site assessment to identify cost-
effective efficiency opportunities. Qualified low- and no-cost measures, such as high-
efficiency lamps, fixtures, and lighting controls, are installed directly at the facility, and
customers are provided with energy efficiency educational materials to support ongoing
savings.
Table 19 -Small Business Direct Install Lighting Program Metrics
Small Business Lighting—Electric
Participation, Savings, and Costs
Conservation Projects 1,924
Overall kWh Savings 18,962,969
Incentive Spend $10,726,872
Non-Incentive Utility Costs $1,498,769
Idaho Energy-Efficiency Rider Spend $12,225,641
Program Activities
In 2025, the Small Business Direct Install Lighting Program continued to perform strongly,
with participation and energy savings exceeding expectations. Customer engagement
was primarily influenced by in-person outreach from participating trade allies, while
information featured on the Avista website helped expand program awareness and
support self-initiated enrollment. Higher-than-expected demand required adaptive
program management, including enhanced coordination with trade allies to balance
installation capacity and minor equipment substitutions to address limited supply
availability. These actions ensured consistent service delivery, minimized installation
delays, and supported continued achievement of cost-effective energy savings
throughout the year.
Program Changes
Beginning in early 2025, several program modifications were implemented to better
manage spending, improve cost-effectiveness, and align with evolving efficiency
standards. Customer eligibility was refined to focus on small commercial customers,
including the removal of municipalities, universities, schools, and hospitals in February
2025, followed by additional exclusions in June 2025 for certain franchise businesses,
landlords with vacant tenant spaces, and parking lot projects. A program-wide threshold
of $0.72 cost per kWh was also established in February 2025 to prioritize higher-value
projects.

In response to efficiency standard updates, product eligibility criteria were tightened to
reflect the sunset of ENERGY STAR° lamp and luminaire specifications and the adoption
of more stringent Design Lights Consortium requirements, reducing the pool of qualifying
equipment. Collectively, these changes were not originally anticipated, however, they
were implemented to ensure continued regulatory compliance, fiscal stewardship, and
alignment with program intent.
Program Marketing
The success of the program continued to rely primarily on participating trade allies to
identify eligible customers and promote program participation through direct outreach and
customer referrals. Additional program awareness was supported through the Avista
website and regional Account Executive outreach. Program marketing emphasized the
streamlined customer experience, including complimentary facility assessments and low-
to no-cost lighting upgrades made possible through direct application of incentives to
contractor invoices. Co-branded program materials and ongoing trade ally engagement
helped build customer trust, increase program visibility, and support participation
throughout Avista's service territory.
Impact Evaluation
The table below shows reported and evaluated electric savings for the Small Business
Direct Install Lighting Program in 2025.
Table 20 -Small Business Direct Install Lighting Program Impact Findings— Electric
Expected Savings Achieved Savings I Realization Rate
Small Business Lighting 18,592,356 18,962,969 102%
Recommendations
The impact evaluation identified no significant recommendations specific to the Small
Business Direct Install Lighting Program. Evaluators found no major data quality or
tracking issues within the sampled projects and reported a verified realization rate of 102
percent, indicating that program savings closely aligned with, and slightly exceeded,
tracked savings.
Plans for 2026
To support cost-effective program delivery and ensure that funding is available to serve a
broad cross-section of small businesses, additional review and approval requirements will
be implemented for incentive requests over $50,000. Program performance, market
conditions, and evaluation findings will continue to be reviewed throughout the year and
incorporated into future program planning as part of Avista's regular annual review cycle.

Commercial/Industrial Prescriptive Non-Lighting Programs
Description
The Commercial/Industrial Prescriptive Non-Lighting Programs provide simple,
standardized incentives for a variety of commercial and industrial energy efficiency
measures. In 2025, this group of programs included the Green Motors Rewind Program,
Commercial Grocer Program, and Commercial Prescriptive Shell Program. These
offerings help customers reduce energy consumption through efficient motor repair,
commercial refrigeration improvements, and building shell insulation upgrades while
providing a streamlined participation experience.
Table 21 -Commercial/Industrial Prescriptive Non-Lighting Program Metrics
Prescriptive Non-Lighting—Electric
Participation, Savings, and Costs
Conservation Projects 5
Overall kWh Savings 20,664
Incentive Spend $15,583
Non-Incentive Utility Costs $1,302
Idaho Energy-Efficiency Rider Spend $16,886
Prescriptive Non-Lighting—Natural Gas
Conservation Projects 2
Overall Therm Savings 169
Incentive Spend $5,909
Non-Incentive Utility Costs $1,018
Idaho Energy-Efficiency Rider Spend $6,927
Program Activities
Green Motors Rewind Program: In 2025, the Green Motors Rewind Program
successfully transitioned to in-house administration following the discontinuation of the
regional Green Motors Practices Group in late 2024. To minimize disruption for customers
and service centers, Avista maintained the existing incentive structure, eligibility
requirements, and RTF savings methodology. Participating service centers continued
providing instant rebates at the time of service and submitted documentation directly to
Avista. Although participation remained limited, the program preserved a pathway for
future qualifying motor rewind projects and maintained continuity for participating
vendors.
Commercial Grocer Program: In 2025, the Commercial Grocer Program continued
supporting energy efficient refrigeration upgrades at grocery and food retail facilities. The
program received applications from national grocery chains implementing equipment
improvements across multiple store locations. Standardized refrigeration equipment and

design practices enabled efficient project review and delivery, allowing the program to
maintain steady participation and verified energy savings while supporting ongoing
customer engagement.
Commercial Prescriptive Shell Program: In 2025, the Commercial Prescriptive Shell
Program supported customers completing insulation improvements in walls, attics, and
roofs as part of renovation, replacement, and code compliance projects. Program
participation and savings remained generally consistent with expectations, and ongoing
coordination with customers and trade allies helped ensure timely project completion and
effective program administration. The program continued to provide a straightforward
incentive pathway for eligible insulation projects while supporting building energy
performance improvements.
Program Changes
In 2025, the Commercial Prescriptive Shell Program was transitioned to the
Commercial/Industrial Site-Specific Program. The change was made to provide greater
flexibility in evaluating insulation projects that did not align well with standardized
prescriptive assumptions and to better accommodate project-specific conditions, savings
calculations, and customer needs. Following this transition, commercial insulation
projects were administered through the Commercial/Industrial Site-Specific Program
rather than the Prescriptive Non-Lighting portfolio.
Additionally, the Green Motors Rewind Program transitioned to in-house administration
following the discontinuation of utility program services previously provided by the Green
Motor Practices Group in late 2024. Program design, incentive levels, and savings
methodologies were maintained to minimize impacts to participating customers and
service centers.
Program Marketing
In 2025, these programs were promoted through Avista's website, Account Executive
outreach, trade ally engagement, and broader commercial energy efficiency marketing
efforts. Account Executives and energy engineers worked directly with customers to
identify project opportunities and increase awareness of available incentives. Marketing
activities also leveraged company-wide conservation campaigns and digital resources to
help customers and contractors identify eligible measures and understand program
requirements.
Impact Evaluation
The table on the next page shows the reported and evaluated electric savings for the
Prescriptive Non-Lighting Program path, as well as realization rates between the
evaluated and reported savings for 2025. Overall, the programs achieved a 90%
realization rate.
30

Table 22 - Commercial/Industrial Prescriptive Non-Lighting Program Impact Findings— Electric
Program Expected Savings Achieved Savings Realization Rate
Green Motors 10,529 7,625 72%
Grocer 2,919 2,919 100%
C/1 Prescriptive Shell 14,280 14,280 100%
Total Commercial/Industrial 27,728 24,825 90%
As shown in the table below, natural gas programs achieved a realization rate of 27%.
Table zs -Commerciainnaustriai vrescriptive Non-Lignting vrogram impact Findings— Natural
Gas
Expected Savings Achieved Savings Realization Rate
(therms) (therms)
C/1 Prescriptive Shell 628 169 277%
Recommendations
Regarding the 27 percent realization rate for the Prescriptive Shell program, evaluators
determined that differences between expected and verified savings methodologies
contributed to the variance. In response, Avista transitioned commercial insulation
projects to the Commercial/Industrial Site-Specific Program in 2025 to allow greater
flexibility in project evaluation and savings determination. Avista will continue to review
program tracking requirements and documentation practices to improve data quality and
support future evaluations.
Plans for 2026
In 2026, Avista will continue supporting eligible Green Motors Rewind and Commercial
Grocer projects while monitoring participation, savings performance, and customer
engagement. Commercial insulation projects will continue to be administered through the
Commercial/Industrial Site-Specific Program, allowing for greater flexibility in project
evaluation and savings determination. Avista will also continue reviewing program
performance and evaluation findings to identify opportunities for process improvements
and effective delivery of commercial and industrial energy efficiency offerings.

Midstream Program
Description
Avista's Commercial/Industrial Midstream program incentivizes the purchase of high-
efficiency HVAC and water heating systems, pumps, and commercial food-service
products and works to ensure these products are always in stock for customers. The
program involves working directly with distributors, who influence the majority of
equipment sales in any given region.
fable /-4 -%,ommercial/Industrial Midstream Program Metrics
Commercial/industrial Midstream—Electric
wEarticiDation. Savinas. and Cost
Conservation Projects 69
Overall kWh Savings 163,691
Incentive Spend $74,140
Non-Incentive Utility Costs $17,373
Idaho Energy-Efficiency Rider Spend $91,513
Commercial/industrial Midstream— Natural Gas
Participation, av n Costs
Conservation Projects 79
Overall Therm Savings 28,137
Incentive Spend $106,564
Non-Incentive Utility Costs $152,768
Idaho Energy-Efficiency Rider Spend $259,332
Program Activities
By working closely with the implementor and evaluator, Avista made key program
adjustments in 2025 that significantly improved realization rates, better aligning expected
savings with program performance. Program participation continues to increase.
Program Changes
In 2025, the program began incentivizing Pump Energy Index (PEI) pumps and heat
pumps for space constrained environments such as manufactured homes. Within the
commercial food service space, new measures included conveyor broilers, gas cooktops,
and pressure fryers. Fryers, steamers and dishwashers were removed from the program
in 2025, along with electric cooktops and natural gas griddles. Only AHR12 and dual-rated
heat pumps were eligible for incentives.
Program Marketing
Midstream program marketing took place primarily through participating distributors. In-
person events, trainings, signage, counter mats and collateral were used to highlight the

program to contractors. Email communication was used for sharing key program
information and deadlines.
Impact Evaluation
The tables below show reported and evaluated electric and natural gas savings for the
Midstream Program in 2025.
Table 25 -Commercial/Industrial Midstream Program Impact Findings—Electric
Expected Savings Achieved Savings
�� -0��� (kWh) (kWh) 1� Realization Rate
Commercial/Industrial 163,821 163,691 100%
Midstream
Table 26 -Commercial/Industrial Midstream Program Impact Findings— Natural Gas
Program Expected Savings Achieved Savings Realization Rate
Commercial/Industrial 28,202 28,137 100%
Midstream
Plans for 2026
In 2026, Avista will consider adjusting incentives as needed to ensure a cost-effective
program. Avista will also add condensing gas unit heaters and radiant heaters while
discontinuing commercial gas rack ovens.

Building Operator Certification Program
Description
Building Operator Certification (BOC) is a national training and certification program which
helps participants develop skills in commercial building operation, with an emphasis on
no- and low-cost solutions. Competency is demonstrated through project work involving
the participants' own buildings and equipment.
Table 27 -Building Operator Certification Program Metrics
Operator
. . ion,
Conservation Projects 1
Overall kWh Savings 119,000
Incentive Spend $0
Non-Incentive Utility Costs $2,484
Idaho Energy-Efficiency Rider Spend $2,484
Building Operator
!Pa rtici patio n, Savings, and Cos?W IL
Conservation Projects -
Overall Therm Savings -
Incentive Spend $0
Non-Incentive Utility Costs $0
Idaho Energy-Efficiency Rider Spend $0
Program Activities
Avista continued partnering with Building Potential to offer all customers managing
commercial buildings a discount on BOC training, which is offered both virtually and in
person throughout the year. Given the opportunity to offer in-person BOC training in the
Spokane area in 2025, Avista actively recruited commercial customers to participate.
Program Changes
No program changes were made in 2025.
Program Marketing
Program staff worked directly with Account Executives to share the program with potential
participants. Program availability is highlighted on an ongoing basis on the Building
Potential website.
Plans for 2026
Avista will continue to highlight this opportunity to interested commercial customers in
2026.

Residential Sector
Avista offers a broad portfolio of residential programs designed to help customers reduce
energy use while improving comfort in their homes. The portfolio is structured to support
the equitable distribution of clean, efficient, and affordable energy benefits across
customer segments throughout the company's Idaho service territory. In 2025, nearly$2.1
million in rebates and direct benefits were provided to Idaho residential customers,
helping offset project costs and enabling customers to complete desired energy efficiency
upgrades. Collectively, programs within the residential portfolio achieved 2,635,482 kWh
and 168,408 therms in energy savings.
Portfolio Performance
The electric portfolio achieved 56 percent of its 2025 planned savings, supported by
strong results from the Residential Shell program, which met 71 percent of planned
savings, and the Midstream program, which achieved 53 percent. While no planned
savings were anticipated for the Fuel Conversion, Home Energy Audit, and Home
Insulation programs, each produced measurable savings that will help to inform future
program planning. The Appliances and ENERGY STAR° Homes programs also
generated measurable savings, though results were below expectations.
The table below shows planned savings assigned to Avista's residential programs for
2025, as well as verified savings and the percentage of planned savings achieved.
Table 28 - Residential Programs Verified vs Planned Savings—Electric
Planned Savings Achieved Savings Percentage of
(kWh) (kWh) Planned Savings
Appliances 109,924 26,382 24%
ENERGY STAR®Homes 108,796 44,243 41%
Fuel Conversion - 82,406 0%
Home Energy Audit - 86,914 0%
Home Insulation Program - 11,436 0%
Residential Midstream 4,254,544 2,234,477 53%
Residential Shell 211,155 149,624 71%
Total Residential _ 4,684,420 2,635,482 56%
The residential natural gas portfolio exceeded its 2025 planned savings, achieving 107
percent of target. Performance was driven primarily by the Appliances program, which
substantially surpassed expectations at 808 percent of planned savings, along with the
Midstream and Shell programs, both of which exceeded 100 percent of planned savings.
Although no savings were planned for the ENERGY STAR' Homes program in 2025, the
program still contributed a modest 301 therms to overall natural gas portfolio savings.

The table below shows planned savings assigned to Avista's residential natural gas
programs for 2025, as well as verified savings and percentage of planned savings
achieved.
Table 29 - Residential Programs Verified vs Planned Savings— Natural Gas
Planned Savings Achieved Savings Percentage of
(therms) (therms) Planned Savings
Appliances 511 4,123 808%
ENERGY STAR®Homes - 301 0%
Residential Midstream 139,458 142,775 102%
Residential Shell 16,975 21,209 125%
Total Residential 5 7 0
Impact Evaluation
The residential sector saw high realization rates in 2025, due primarily to high realization
rates for the ENERGY STAR° Homes and Midstream programs for both electric and
natural gas. See program summaries, as well as Appendices A and B, Electric and Natural
Gas Impact Evaluation Reports, for additional information.
Electric: Verified savings of 2,635,482 kWh, resulting in a realization rate of 98
percent.
Natural Gas: Verified savings of 163,005 therms, resulting in a realization rate of
94 percent.
Cost-Effectiveness
The tables below show residential cost-effectiveness results by fuel type.
Table 30 - Residential Cost-Effectiveness Results— Electric
Cost-Effectiveness Test Benefit/Cost Ratio
Total Resource Cost(TRC) $3,467,119 $4,796,677 0.72
Utility Cost Test(UCT) $3,467,119 $1,699,667 2.04
Participant Cost Test(PCT) $4,358,880 $3,988,771 1.09
Ratepayer Impact(RIM) $3,467,119 $1,885,246 1.84
Table 31 - Residential Cost-Effectiveness Results— Natural Gas
-.LCost-Effectiveness Test Benefits Costs Benefit/Cost Ratio
Total Resource Cost (TRC) $1,623,210 $2,058,662 0.79
Utility Cost Test (UCT) $1,623,210 $1,465,266 1.11
Participant Cost Test(PCT) $2,831,136 $1,801,322 1.57
Ratepayer Impact(RIM) $1,623,210 $1,563,467 1.04
36

Marketing
In 2025, Avista continued to evolve its residential energy efficiency marketing approach
to better align with how customers seek out and engage with information. Building on
prior-year efforts, the company emphasized digital-first, audience-informed tactics while
maintaining a mix of owned, paid, and earned channels to support broad awareness of
energy-saving behaviors, rebates, and programs.
Seasonal education remained a core strategy, with campaigns such as "winter bill" and
general energy-saving tips helping customers better understand actions they could take
to manage energy use and costs during higher-demand periods. These messages were
reinforced through email outreach, bill inserts (where timing allowed), Avista's customer
newsletter, social media, and targeted digital advertising.
Program promotion was delivered consistently throughout the year through the "rebates"
campaign. While the campaign was primarily digital, print ads also ran in local
publications. Digital content was promoted in both English and Spanish, increasing
awareness of Avista's incentive programs designed to help make energy-efficient
equipment upgrades more accessible.
Avista also leveraged its website as a key engagement tool, making ongoing updates and
improvements to residential energy efficiency content to reflect current programs, clarify
customer pathways, and align with paid and organic outreach. Web content supporting
residential energy efficiency programs continued to be available in Spanish, with Russian
added later in the year. Energy efficiency pages remained among the most-viewed pages
on myavista.com, with paid advertising contributing to traffic and engagement.
In addition to paid and owned channels, residential energy efficiency awareness was
supported through community sponsorships and local events, where messaging was
integrated into programs, signage and in-venue placements. These efforts helped
reinforce energy efficiency concepts in trusted, familiar settings.
Overall, Avista's 2025 residential marketing efforts focused on increasing exposure to
energy efficiency information, improving message relevance, and maintaining consistent,
year-round visibility across platforms customers already use. The overarching goal of
these efforts was to support broader awareness of Idaho residential energy efficiency
programs.
Power of Change
A primary focus in 2025 was the continuation of Avista's Power of Change campaign,
which ran in multiple phases throughout the year. The campaign delivered seasonally
relevant, benefits-driven messaging designed to make energy efficiency relatable to
everyday life. Power of Change residential messages offered tips on low-cost ways to
save energy that were delivered in a light-hearted and humorous tone. It was designed
37

to increase customer awareness and engagement with energy efficiency, helping drive
program participation.
Creative assets were refreshed and optimized throughout the year based on performance
insights, with messaging tailored by season and delivered through digital display, search,
social media, streaming and video platforms, including YouTube and connected TV. Ads
ran in six-week phases, with a total of six ads per phase.
Figure 3 - Residential "Power of Change"Ads
THE
POWER POWER POWER
OF OF OF
CHANqF
of the YtIor,
"wis TA
38

Residential Program Summaries
Midstream Program
Description
Avista's Residential Midstream program incentivizes the purchase of high-efficiency
HVAC and water heating equipment and works to ensure these products are always in
stock for customers. The program involves working directly with distributors, who
influence the majority of equipment sales in any given region.
cable 32 -Residential Midstream Program Metrics
Residential Midstream — Electric
Participation, Savings, and Costs
Conservation Projects 1,147
Overall kWh Savings 2,234,477
Incentive Spend $560,250
Non-Incentive Utility Costs $670,887
Idaho Energy-Efficiency Rider Spend $1,231,137
Residential Midstream—Natural Gas
Participation, Savings' and Costs
Conservation Projects 1,891
Overall Therm Savings 142,775
Incentive Spend $738,100
Non-Incentive Utility Costs $202,057
Idaho Energy-Efficiency Rider Spend $940,157
Program Activities
By focusing efforts on distributors, the Midstream program leverages their recognized
influence over contractors and specific equipment sales while mitigating many
participation barriers. Distributors work with contractors to submit claims for Avista
customers, and claims are then paid promptly. This approach benefits both the customer
as well as the company. Customers have improved access, as they may receive an
incentive without having to complete any paperwork or have background knowledge of
the rebate program, and Avista gains additional savings without the burden of customers
having to submit paperwork to the utility.
Program participation continues to increase, and Midstream was a top performing
program in both the electric and natural gas portfolios. For 2025, the program achieved
2.2 million kWh in verified savings, as well as 142,775 therms in verified savings, which
was over 100 percent of planned savings.

Program Changes
By working closely with the implementor and evaluator, Avista made key program
adjustments in 2025 that significantly improved realization rates, better aligning expected
savings with program performance. Additionally, the program began incentivizing heat
pumps for space constrained environments, such as manufactured homes. Both AHR12
and dual-rated heat pumps were eligible for incentives.
Program Marketing
Midstream program marketing takes place primarily through participating distributors. In-
person events, trainings, signage, counter mats and collateral are utilized to highlight the
program to contractors. Email communication was used for sharing key program
information and deadlines.
Impact Evaluation
The tables below show reported and evaluated electric and natural gas savings for the
Midstream Program in 2025.
Table 33 - Residential Midstream Program Impact Findings— Electric
Expected Savings IlLJ Achieved Savings Realization Rate
Residential Midstream 2,231,463 2,234,477 100%
Table 34 - Residential Midstream Program Impact Findings— Natural Gas
Expected Savings Achieved Savings Realization Rate
(therms) (therms)
Residential Midstream 147,031 142,775 97%
Recommendations
In 2025, Idaho PUC staff encouraged Avista to change its evaluation method for
residential furnaces from a treatment-only billing data regression analysis used by the
evaluator to a post-program regression analysis, resulting in a slight decrease in verified
savings per residential furnace'. Staff stated the revised methodology would reduce bias
by considering program participants and statistically similar non-participants The baseline
and expected full-load hours values for residential boilers were also adjusted to account
for boiler sizes at the recommendation of the evaluator.
Plans for 2026
In 2026, Avista will consider adjusting incentives as needed to ensure a cost-effective
program.
5 See Order No.36975(Case Nos.AVU-E-25-12 and AVU-G-25-09)

Prescriptive Programs
Prescriptive programs provide customers with a streamlined path to implement qualifying
energy efficiency upgrades through pre-defined incentives, eligibility requirements, and
savings values. In 2025, the program supported a variety of residential energy-saving
opportunities designed to reduce energy consumption, improve customer comfort, and
lower utility costs. Prescriptive measures are evaluated using standardized savings
assumptions based on typical installations and operating conditions rather than project-
specific analyses. These measures are generally characterized by consistent
performance, broad applicability, and a level of complexity that does not warrant a
customized approach, making them well-suited for standardized program delivery.
ENERGY STAR°/NEEM Manufactured Homes Program
Description
The Idaho Manufactured Home Rebate program provides incentives to customers who
purchase qualifying ENERGY STAR° certified manufactured homes through NEEM 2.0.
Eligible homes must be new primary residences and use Avista-provided electricity for
space heating and/or water heating. The program supports the adoption of high-efficiency
manufactured homes that reduce energy use, lower utility costs, and improve customer
comfort.
Table 35 -ENERGY STAR°/NEEM Manufactured Homes Program Metrics
ENERGY .a
Homes— Electric
Karticipation, Savings, and Costs
Conservation Projects 12
Overall kWh Savings 44,243
Incentive Spend $12,000
Non-Incentive Utility Costs $22,617
Idaho Energy-Efficiency Rider Spend $34,617
STAR'ENERGY
Homes— Natural Gas
Participation, Savings, and Costs
Conservation Projects 2
Overall Therm Savings 301
Incentive Spend $1,200
Non-Incentive Utility Costs $739
Idaho Energy-Efficiency Rider Spend $1,939
Program Activities
In 2025, the Idaho Manufactured Home Rebate program continued to support the
adoption of high-efficiency manufactured homes for residential customers. Avista
monitored the updated RTF to measure guidance during the year and evaluated the
impact of revised baseline assumptions on program offerings. This review helped inform

program adjustments to maintain alignment with current savings assumptions while
continuing to provide customers with an energy efficiency rebate pathway.
Program Changes
In 2025, Avista evaluated updates to the Idaho Manufactured Home Rebate program in
response to revised measure requirements and savings assumptions. Planned updates
included transitioning the program from an electric and natural gas offering to an electric-
only structure, updating eligibility from NEEM v1.1 to NEEM v2.0 certified homes, and
introducing tiered incentives based on home size. These planned changes were intended
to allow Avista to continue offering the program while better aligning with current measure
requirements and available savings assumptions.
Program Marketing
Marketing efforts throughout the year were primarily focused on planning updates to
program materials, including rebate applications, web content, and customer-facing
flyers. The program did not have a dedicated direct marketing campaign but remained
available through Avista's main rebate webpage and broader Power of Change rebate
messaging, where customers can view the manufactured home rebate alongside other
residential offerings.
Impact Evaluation
The tables below show reported and evaluated electric and natural gas savings for the
ENERGY STAR°/NEEM Manufactured Homes program in 2025.
Table 36 - ENERGY STAR°/NEEM Manufactured Homes Program Impact Findings—Electric
Program Expected Savings Achieved Savings Realization Rate
ENERGY STAR' Homes 39,487 44,243 112%
Table 37 - ENERGY STAR®/NEEM Manufactured Homes Program Impact Findings— Natural Gas
Expected Savings Achieved Savings Realization Rate
(therms) (therms) I
ENERGY STAR° Homes 268 301 112%
Recommendations
The evaluators found the ENERGY STAR° Homes program performed well in 2025, with
verified savings exceeding projected levels. Their primary recommendation was forAvista
to continue strengthening the alignment between its savings assumptions and applicable
RTF inputs, including customer location, heating zone, and fuel type. Avista will review
these recommendations and update program assumptions and tracking practices where
appropriate.

Plans for 2026
In 2026, Avista plans to continue the Idaho Manufactured Home Rebate program with
updates informed by 2025 program performance, revised RTF measure guidance, and
evaluator feedback. Planned changes include transitioning to an electric-only offering,
updating eligibility to NEEM v2.0 certified homes, and aligning incentives by home size.
Avista will also continue reviewing savings assumptions and tracking practices to support
consistency with applicable RTF inputs and evaluation requirements.
Residential Appliances Program
Description
The Residential Appliances program provides rebates to qualified residential customers
who purchase eligible ENERGY STAR' certified appliances. Eligible measures include
refrigerators, freezers, front-load washers, and front-load dryers. The program offers a
prescriptive pathway for customers to adopt higher-efficiency appliances that reduce
household energy use.
Table 38 - Residential Appliances Program Metrics
Appliances— Electric
Participation, Savings, and Costs
Conservation Projects 569
Overall kWh Savings 26,382
Incentive Spend $45,553
Non-Incentive Utility Costs $4,709
Idaho Energy-Efficiency Rider Spend $50,261
Appliances
Participation, Savings, and Costs
Conservation Projects 283
Overall Therm Savings 4,123
Incentive Spend $29,194
Non-Incentive Utility Costs $2,454
Idaho Energy-Efficiency Rider Spend $31,648
Program Activities
In 2025, the Residential Appliances program continued to offer a prescriptive rebate
pathway for qualifying ENERGY STAR' certified appliances. Avista reviewed program
performance and evaluator feedback and began planning updates to the clothes washer
and clothes dryer offerings to better align program eligibility, documentation, and savings
assumptions with current measure requirements.

Program Changes
During the year, Avista began evaluating updates to the Residential Appliances program
based on program performance, market conditions, RTF values, and evaluator feedback.
Planned updates focused on clarifying eligibility requirements for clothes washer and
clothes dryer rebates, including service and fuel-type requirements needed to better align
with current savings assumptions. The smart thermostat measure was discontinued in
2025. These changes were intended to improve program clarity, support more accurate
reporting, and maintain alignment with applicable measure requirements.
Program Marketing
Marketing efforts for the Residential Appliances Program were maintained through
Avista's main rebate webpage and broader residential rebate communications.
Customers could view appliance rebates alongside other available residential offerings
through Avista's online rebate resources and general Power of Change rebate
messaging. Avista also began planning updates to program materials to reflect changes
to eligible measures and customer requirements.
Impact Evaluation
The tables below show reported and evaluated electric and natural gas savings for the
Residential Appliances program in 2025.
Table 39 - Residential Appliances Program Impact Findings— Electric
Expected Savings 1 Achieved Savings Realization Rate
Appliances 106,215 26,382 25%
Table 40 - Residential Appliances Program Impact Findings— Natural Gas
Expected Savings Achieved Savings Realization Rate
(therms) (therms)
Appliances 5,595 4,123 74%
Recommendations
The 2025 electric and gas evaluations found that Residential Appliances realization rates
were impacted by differences between Avista's expected savings assumptions and the
more detailed RTF measure requirements. Evaluators recommended improving
alignment with applicable RTF inputs, including equipment efficiency, fuel type, water
heating type, and product documentation. Avista will apply these recommendations and
update program eligibility, documentation requirements, and tracking practices as
appropriate.
Plans for 2026
In 2026, Avista plans to continue the Residential Appliances program with updates
informed by program performance, market conditions, and evaluator feedback. Planned

updates include revised eligibility requirements for clothes washer and clothes dryer
rebates to better align with current savings assumptions and applicable fuel-type
requirements. Avista will also continue reviewing documentation and tracking practices to
support improved consistency between reported and verified savings. While the smart
thermostat measure was discontinued in 2025, Avista is evaluating whether a future
offering may be appropriate under updated program criteria.
Home Insulation Program
Description
Avista's Home Insulation Program (HIP) encourages residential customers to improve
their home's building envelope by adding insulation and reducing air leakage to lower
energy use and improve comfort. The program provides incentives for qualifying attic,
wall, floor, and duct insulation, as well as duct sealing. In 2025, insulation measures were
initially offered through a prescriptive pathway before transitioning to a direct-install model
in August 2025. Under this model, participating contractors assess the home, confirm
eligibility, install qualifying measures, and handle required documentation, with rebates
applied upfront to reduce customer costs.
Table 41 - Home Insulation Program Metrics
ProgramHome Insulation
Participation, Savings, and Costs
Conservation Projects 8
Overall kWh Savings 11,436
Incentive Spend $8,754
Non-Incentive Utility Costs $5,846
Idaho Energy-Efficiency Rider Spend $14,600
Program Activities
Through July 2025, insulation measures were offered through a prescriptive pathway,
providing customers with a straightforward way to complete qualifying insulation projects
and receive incentives based on predefined savings and eligibility requirements. This
pathway continued to deliver reliable energy savings and comfort improvements, with
impact evaluation results showing insulation savings closely matching or slightly
exceeding expected values across both the electric and gas evaluations.
Building on concerns raised in 2024 regarding contractor practices and quality of work,
Avista completed its third-party insulation inspection effort in 2025 to verify installation
quality and program compliance. The results of this quality assurance work reinforced the
need for closer coordination with participating contractors and stronger program
oversight. In response, Avista transitioned insulation measures to a direct-install model
under the HIP in August 2025 to simplify participation and improve customer experience.
Under this model, participating contractors assess the home, confirm eligibility, install

qualifying measures, and handle required documentation, with rebates applied upfront to
reduce customer costs, allowing Avista and its third-party implementation team to
adaptively manage the program while making the pathway easier for customers to
complete.
Program Changes
In August 2025, Avista transitioned long-standing insulation measures from a prescriptive
pathway to a direct-install model, in an effort to simplify participation and improve
customer experience. Under the direct-install model, participating contractors assess the
home, confirm eligibility, install qualifying measures, and handle required documentation,
with rebates applied upfront to reduce customer out-of-pocket costs. This change was
informed by program performance and quality assurance findings and was intended to
strengthen contractor oversight while making the pathway easier for customers to
complete. In Idaho, the program was offered for electrically-heated homes.
Program Marketing
Avista supported the HIP through customer communications and outreach efforts,
including a series of three emails preparing customers for the end of the previous offering
and introducing the new direct-install model, along with advertising placement, bill inserts,
and promotion at outreach events. The program is delivered in partnership with a third-
party implementer who took a lead role in marketing, while participating installers
conducted their own outreach to promote their businesses and generate customer
interest.
Impact Evaluation
The tables below show reported and evaluated electric and natural gas savings for the
HIP in 2025.
Table 42 - Home Insulation Program Impact Findings— Electric
Expected Savings Achieved Savings Realization Rate
Home Insulation Program 11,327 11,436 101%
Recommendations
For 2025, the evaluators found the HIP performed well, with insulation savings closely
matching or slightly exceeding expected values. The primary recommendation was to
continue aligning expected savings with applicable RTF inputs, including heating zone,
heating equipment, and the appropriate insulation R-value change. The evaluators also
recommended assigning savings to the nearest RTF insulation bucket to improve
consistency between expected and verified savings, and continuing to verify project
documentation to confirm measure eligibility and accurate fuel-type assignment. Avista
will apply these recommendations as it continues to refine the program while updating
savings assumptions and tracking practices where appropriate.
46

Plans for 2026
In 2026, Avista plans to continue delivering the program. Building on 2025 program
performance, quality assurance findings, and evaluator feedback, Avista will continue
refining program processes, contractor oversight, and documentation practices.
Residential Fuel Conversion Program
Description
Avista's Residential Fuel Conversion program provides qualifying Idaho Schedule 1
residential electric customers with an incentive to convert electric straight-resistance
space and water heating to high-efficiency natural gas equipment. Eligible conversions
include electric baseboard or forced-air furnace heat to a natural gas forced-air furnace,
as well as electric furnace and water heater combinations to natural gas. To qualify,
annual pre-upgrade usage must show 4,000 kWh or more of electric heating use and less
than 340 therms of natural gas use. Equipment must be installed by a licensed contractor,
with required documentation including project invoices and AHRI certification. Rebates
are paid to the customer after installation and receipt of documentation.
Table 43 - Residential Fuel Conversion Program Metrics
Fuel Conversion— Electric
Participation, Savings, and Costs
Conservation Projects 11
Overall kWh Savings 82,406
Incentive Spend $26,100
Non-Incentive Utility Costs $24,848
Idaho Energy-Efficiency Rider Spend $50,948
Program Activities
In 2025, the Residential Fuel Conversion program continued to support customers
converting electric straight-resistance space and water heating to high-efficiency natural
gas equipment through its contractor-installed delivery model, with eligibility confirmed
through a review of customer energy usage. Impact evaluation results reinforced the
program's strong performance, with verified savings closely matching expected values for
most measures. The evaluators identified a small number of installed water heaters that
fell slightly below the required efficiency level, which Avista can address through
continued documentation review and verification of equipment specifications prior to
incentive payment.
Program Changes
No significant changes were made to the Residential Fuel Conversion program during
2025. The program continued to operate under its existing eligibility requirements,
incentive structure, and prescriptive pathway.

Program Marketing
In 2025, marketing efforts were maintained through Avista's main rebate webpage and
broader residential rebate communications, where customers could view the fuel
conversion rebate alongside other available offerings.
Impact Evaluation
The table below shows reported and evaluated electric savings for the Residential Fuel
Conversion program in 2025.
Table 44 - Residential Conversion Program Impact Findings—Electric
Expected Savings Achieved Savings Realizatio:n R!!e
. .
"FuelConversion 90,844 82,406 91%
Recommendations
Evaluators found the Residential Fuel Conversion program performed well in 2025, with
verified electric savings closely matching expected values across most measures. The
main finding was that two sampled water heaters in the electric-to-natural gas furnace
and water heater combination measure did not meet the required efficiency level, lowering
that measure's realization rate. The evaluators recommended verifying equipment
efficiency through AHRI documentation and full model information prior to incentivizing
installation and continuing to review tracking data for accurate heating fuel and equipment
information. Avista will apply these recommendations and update documentation and
tracking practices as appropriate.
Plans for 2026
In 2026, Avista plans to continue offering the Residential Fuel Conversion program to
qualifying Idaho customers, incorporating impact evaluation feedback to strengthen
program delivery. Building on 2025 evaluation findings, Avista will focus on verifying
equipment efficiency through AHRI documentation and complete model information prior
to incentive payment, as well as continuing to review tracking data for accurate heating
fuel and equipment details. These efforts are intended to support accurate savings
reporting and ensure that incentivized equipment meets applicable efficiency
requirements.

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 +z) - nome r-nergy(audit Program Metrics
ome Energy Audit—Electric
Partic pat on, Savings, ancrCosts
Conservation Projects 108
Overall kWh Savings 86,914
Incentive Spend $-
Non-Incentive Utility Costs $2,512
Idaho Energy-Efficiency Rider Spend $2,512
Home Energy Audit—Natural Gas
Participation, Savings, and Costs
Conservation Projects 190
Overall Therm Savings -
Incentive Spend $-
Non-Incentive Utility Costs $-
Idaho Energy-Efficiency Rider Spend $-
Program Activities
The program remained popular in 2025 and approximately 40 audits were conducted
each week. The waitlist time ranged from two to six months; this variability was due to
marketing efforts that caused surges of applications.
Program Changes
There were no program changes in 2025.
Program Marketing
A marketing push using targeted emails resulted in a surge in applications during the
summer months of 2025.
Impact Evaluation
The tables on the next page show reported and evaluated electric and natural gas savings
for the Home Energy Audit program in 2025.

Table 46 - Home Energy Audit Program Impact Findings—Electric
Program Expected Savings Achieved Savings Realization Rate
Home Energy Audit - 86,914 NA%
Table 47 - Home Energy Audit Program Impact Findings— Natural Gas
Expected Savings Achieved Savings Realization Rate
(therms) (therms)
Home Energy Audit - - NA%
Recommendations
Initially, Avista planned to continue the program into 2026; however, after reviewing its
cost-effectiveness, it was determined that continuing to offer the program to Idaho natural
gas customers would not be cost-effective.
Plans for 2026
Offering home energy audits for Idaho natural gas-heated homes proved not to be cost-
effective, and customers were notified that the program would end beginning in March
2026.

Low-Income Program
Description
Avista partners with a Community Action Partnership (CAP) agency, CAP Lewiston, to
deliver weatherization and energy efficiency services to income-qualified households
across ten counties in the company's Idaho service territory. Through this partnership,
customers gain access to a comprehensive network of programs and funding sources
designed to improve home energy performance, reduce utility costs, and enhance comfort
and safety. After confirming income qualification, CAP provides home energy
assessments, conservation education, and installation of eligible energy-efficiency
measures.
Program Activities
In 2025, Avista provided CAP Lewiston with $875,000 in weatherization funding, along
with an additional $75,000 dedicated to conservation education and customer outreach
activities. This funding supports a wide range of electric and natural gas efficiency
improvements tailored to the specific needs of each participating household.
CAP Lewiston maintains flexibility in allocating program funds between electric and
natural gas measures, allowing services to be targeted where they will provide the
greatest benefit. To qualify for residential shell improvements, such as insulation,
windows, and air sealing measures, participating homes must meet minimum annual
energy-use thresholds for Avista electric or natural gas service. Eligibility requirements
also apply to heating system upgrades, including conversions from electric resistance
heating to heat pumps or natural gas furnaces. These requirements help ensure that
installed measures deliver meaningful energy savings and long-term value for customers.
The annual funding allocation includes reimbursement for administrative and program
support activities, enabling the agency to effectively deliver services throughout Avista's
Idaho service territory. In addition, a portion of available funding may be used for eligible
health and safety improvements and necessary home repairs that support the successful
installation of energy-efficiency measures.
During 2025, the program served income-qualified electric and natural gas customers
throughout Avista's Idaho service territory, delivering a portfolio of cost-effective
weatherization and energy efficiency improvements. Program achievements are
measured through the installation of energy-saving measures, including insulation, air
sealing, heating system upgrades, and other qualifying improvements that reduce energy
consumption and improve home comfort for participating households.
51

Table 48 - Low-Income Program Metrics
Low Income— Electric
Participation, Savings, and Costs
Conservation Projects 124
Overall kWh Savings 142,112
Incentive Spend $842,002
Non-Incentive Utility Costs $160,305
Idaho Energy-Efficiency Rider Spend $1,002,306
Low Income— Natural Gas
Participation, Savings, and Costs
Conservation Projects 134
Overall Therm Savings 3,833
Incentive Spend $476,684
Non-Incentive Utility Costs $23,290
Idaho Energy-Efficiency Rider Spend $499,974
Avista continued to reimburse CAP for 100 percent of the cost of installing most approved
weatherization and energy efficiency measures throughout 2025. This funding structure
enables agencies to deliver comprehensive weatherization services to income-qualified
customers while maximizing energy savings and improving home comfort.
Program results in 2025 demonstrated strong energy savings across both electric and
natural gas customer segments. Because weatherization services are provided based on
customer eligibility and available program capacity rather than heating fuel type, annual
savings can vary between electric and natural gas measures. Program performance is
largely influenced by the characteristics of homes served, the condition of existing
equipment, and the specific energy efficiency opportunities identified during the home
assessment process.
CAP Lewiston may also receive partial reimbursement for measures included on the
acceptable measures list that do not independently meet cost-effectiveness
requirements. In these cases, reimbursement is based on the avoided-cost energy value
associated with the improvement. This approach encourages agencies to prioritize
measures that deliver the greatest energy savings and value from a utility perspective
while maintaining flexibility to address customer needs.
To support comprehensive home improvements, agencies may also utilize approved
health and safety funding to cover eligible costs associated with measures that would
otherwise receive only partial reimbursement. This flexibility helps ensure that critical
upgrades can be completed when necessary, allowing agencies to address both energy

efficiency and health and safety concerns while delivering lasting benefits to participating
households.
Table 49 - Low-Income Program Reported Savings
Program
Planned Savings
Electric(kWh) 121,549 142,112 117%
Natural Gas (Therms) 4,239 3,833 90%
Table 50 - Low-Income Program Approved Measure List
Electric Efficiency Measures Natural Gas Efficiency Measures
Air infiltration Boiler(96% AFUE)
Attic insulation Doors—ENERGY STAR'-rated Furnace (95%
Doors— ENERGY STAR°-rated Duct insulation AFUE)
Duct sealing Water heater(storage) <55 gallons .65 EF
Electric to air-source heat pump (9 HSPF) Water heater(tankless) .82 EF
Electric to ductless heat pump (10 HSPF) Windows— ENERGY STAR'-rated, U-factor .30
Electric to natural gas furnace conversion Floor or less
insulation
LED lamps
Refrigerator— ENERGY STAR'-rated Wall
insulation
Windows— ENERGY STAR°-rated, U-factor .30
or less
Table 51 - Low-Income Program Qualified Rebate Measure List
Electric Efficiency Measures Natural Gas Efficiency Measures
Air-source heat pump replacement(9 HSPF): Air infiltration: $73.44
$636.45 Attic insulation: $1.25/sq ft
Door sweep: $3 Door sweep: $1/sq ft
Electric to natural gas space and water heat: Duct insulation: $.096/sq ft
$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: $.75/sq ft
Marketing and Outreach
Customers receiving weatherization services are typically referred through a partner
agency's energy assistance program or through Avista's internal customer support
channels. Internal referrals may come from the company's Energy Efficiency department
or Customer Service organization, including the Customer Assistance Referral and
53

Evaluation Services (CARES) team. CARES provides specialized assistance to
customers who are elderly, have disabilities, are income-qualified, or are experiencing
financial, employment-related, or health-related challenges, and may identify customers
who could benefit from weatherization services.
Avista also helps connect customers to weatherization services through community
outreach efforts. The Community and Economic Vitality team collaborates with Energy
Efficiency staff and community partners to educate and support income-qualified
customers, seniors, veterans, and individuals with disabilities. Through key outreach
activities including energy conservation workshops, participation in food banks and
community resource events, mobile outreach efforts, and direct customer education,
customers receive regarding available assistance programs, low- or no-cost
weatherization opportunities, and practical energy-saving strategies that can improve
home comfort and reduce energy costs.
Throughout 2025, outreach efforts in Idaho continued to expand through Avista's
partnership with the CAP Lewiston. Agency staff dedicated approximately 1,150 hours to
conservation education and customer engagement activities. A combination of phone
calls, emails, flyers, presentations, videos, community events (including the North Idaho
Student Health & Wellness Fair, and the Idaho Foodbank's North Central Annual Partner
Conference), food banks, mobile pantries, and in-person interactions reached more than
3,700 community members with energy efficiency and weatherization information. These
events provided opportunities to educate customers on low-cost weatherization
strategies, energy-saving habits, and available Avista assistance programs.
In addition to broader community outreach, agency staff provided personalized
conservation education to customers through one-on-one conversations in person and
over the phone. More than 80 customers received individualized guidance on reducing
energy consumption, improving home comfort, and making effective use of
weatherization materials. CAP Lewiston also distributed hundreds of conservation
education and weatherization kits containing items such as window film, door weather
stripping, LED lighting, and other energy-saving products.
Throughout the year, CAP Lewiston continued to refine its outreach approach based on
customer feedback and program experience. Preassembled conservation education kits
with instructional materials proved to be an effective strategy, allowing staff to spend more
time engaging directly with customers while ensuring consistent distribution of energy-
saving resources. Agency staff also observed strong customer interest in weatherization
products such as window film and door sealing materials, which provide immediate and
tangible benefits for improving comfort and reducing energy use. These insights will
continue to inform outreach and conservation education efforts moving forward.
54

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The Tables below show the low-income sector cost-effectiveness results by fuel type.
Table 52 -Low-Income Program Cost-Effectiveness Results—Electric
Cost-Effectiveness Test Benefits Benefit/Cost Ratio
Total Resource Cost(TRC) $184,315 $892,480 0.21
Utility Cost Test(UCT) $184,315 $1,002,306 0.18
Participant Cost Test(PCT) $1,026,316 $732,175 1.40
Ratepayer Impact(RIM) $184,315 $1,012,313 0.18
Table 53 - Low-Income Program Cost-Effectiveness Results—Natural Gas
Cost-Effectivenes;�Test —Benefits Costs Benefit/Cost Ratio
Total Resource Cost(TRC) $45,002 $438,599 0.10
Utility Cost Test(UCT) $45,002 $499,974 0.09
Participant Cost Test(PCT) $521,686 $415,309 1.26
Ratepayer Impact(RIM) $45,002 $502,209 0.09
Impact Evaluation and Recommendations
On the electric side, the Low-Income Program's impact evaluation showed verified
savings below expected savings, with a relatively low realization rate. The main reason
for the lower realization rate was that Avista's expected savings methodology was less

granular than the RTF unit energy savings workbooks used by the evaluators. Evaluators
also noted that low-income tracking data and documentation were often missing key
measure details, which required assumptions about factors such as heating equipment
type and baseline versus installed equipment efficiency. The evaluators recommended
improving tracking data completeness and consistency, especially for heating type,
measure quantities, and measure-specific attributes, so future evaluations can rely less
on secondary data and conservative assumptions.
For natural gas, the Low-Income Program's impact evaluation found the program
performed very close to expected savings. The primary issue identified was not program
performance, but data quality and tracking limitations. Differences between reported and
verified savings were primarily tied to inconsistent measure quantity fields, missing details
like exterior door square footage and installed window type, and the need to apply single-
family RTF values to manufactured and multifamily homes when more specific data was
unavailable. The evaluator's recommendation was to improve future tracking by
standardizing measure-specific fields, capturing key RTF inputs, and adding eligibility
checks — such as confirming ENERGY STAR°certification for storage tank water heaters
— to reduce assumptions and improve future realization rate accuracy.
Plans for 2026
Avista will continue advancing weatherization efforts in Idaho through its partnership with
CAP Lewiston. Through the intake and eligibility review process, the agency will identify
households with high energy burdens, and Avista will support customer identification,
outreach, and engagement efforts to ensure eligible customers can access available
energy efficiency services. The company will also consider the evaluator's impact
evaluation recommendations and will make changes to reporting process to capture
additional detail as needed.

Pilot Programs
Compressed Air Leak Detection
Description
The Compressed Air Leak Detection Pilot program tests a vendor-supported approach to
identifying and verifying compressed air leaks at Idaho commercial and industrial
customer facilities using acoustic imaging technology. The pilot provides compressed air
system scans, leak identification, repair support, and follow-up verification scans to help
customers reduce compressed air waste while allowing Avista to evaluate program
delivery, customer participation, and future program potential.
Program Activities
In 2025, Avista continued implementation of the Compressed Air Leak Detection Pilot for
Idaho commercial and industrial customers. The pilot used a vendor-supported approach
to identify and verify compressed air leaks through acoustic imaging technology.
Participating customers received an initial system scan to detect leaks, support for
completing repairs, and a follow-up verification scan to confirm that identified leaks had
been addressed. This approach allowed Avista to evaluate customer participation,
program delivery processes, and the effectiveness of using acoustic imaging to identify
energy-saving opportunities in compressed air systems.
Throughout the year, the program team worked closely with the pilot vendor and internal
engineering staff to review scan results, verify reporting assumptions, and refine analysis
methods used to estimate savings. Lessons learned from customer participation, repair
verification, reporting requirements, and program administration helped inform potential
future program design and delivery approaches.
Activities in 2025 focused on refining the pilot delivery model and improving data
collection processes. During the year, the program implemented a customer participation
agreement that standardized participation requirements and collected key compressed
air system information to support project evaluation and savings analysis. The pilot also
transitioned away from customer self-reported repair activities, instead emphasizing
verified repair completion and follow-up leak detection scans to improve consistency, data
quality, and program oversight. These enhancements helped Avista better evaluate
customer participation, program administration, and opportunities for future program
development.
Plans for 2026
This Pilot will continue into 2026.
57

Research and Development
Consistent with Order No. 35129 in Case Nos. AVU-E-20-13 and AVU-G-20-08, Avista
has continued to evaluate research and development (R&D) opportunities that could
provide benefits to its Idaho customers and include measurable objectives and
performance metrics. While the company has not sought to re-establish R&D funding for
any projects to date, it remains committed to identifying and pursuing appropriate
opportunities. Should such an opportunity arise, Avista will submit a proposal to the IPUC
for review and approval.

Regional Market Transformation
Avista's local energy efficiency portfolio includes programs and supporting infrastructure
designed to increase and accelerate adoption of energy efficiency measures across its
service territory. These efforts are delivered through a combination of financial incentives,
technical assistance, program outreach, and customer education.
Avista alone cannot independently create meaningful impacts in regional or natural
markets. As a result, utilities across the Pacific Northwest have collaborated through
NEEA to address opportunities that extend beyond the scope or reach of any individual
utility. NEEA is an alliance of utilities and energy efficiency organizations that pools
resources and shares risk to advance energy efficiency. It supports market transformation
by using data and market relationships to influence business practices, improve product
testing and performance, and help make efficient products and practices more widely
available.Avista has participated in and funded NEEA since the organization was founded
in 1997.
Utilities, energy efficiency administrators, and the RTF benefit from NEEA's work through
shared knowledge, new conservation measures, and market changes that generate
energy savings. Over time, these efforts help make energy efficiency a self-sustaining
market standard.
The table below presents 2025 NEEA savings and associated Idaho costs, excluding
Avista's internal administrative costs related to participation in NEEA activities and
studies. NEEA costs include 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 administrative costs.
Table 54 - NEEA Energy Savings and Participation Costs
Pr FuelType 2025 NEEA Energy 2025 NEEA ri Avista 2025-2029
1 Savings I Participation Costs Funding Share
Electric 6,833 MWh $792,741 2.18%
(0.78 aMW)
Natural Gas 302,207 therms $202,425 3.82%
Avista will continue to collaborate closely with NEEAand other regional partners to identify
shared priorities and objectives, while also advancing a more comprehensive and
customized local market transformation strategy that includes additional investment in,
and direct coordination with, the supply chain.
Electric Energy Savings Share
Values provided in NEEA's 2025 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).
In 2025, 2,978 MWh were attributed to residential initiatives, and 3,416 MWh were
attributed to commercial initiatives. The remaining 438 MWh were attributed to industrial
and agricultural initiatives.
Natural Gas Energy Savings Share
Over 99 percent of the 302,207 therms acquired through NEEA natural gas savings in
Idaho in 2025 were attributed to residential codes related to new construction. The
remaining savings were attributed to indirect gas savings (envelope measures for
manufactured homes and extended motor products).

Glossary of Terms
Advanced Metering Infrastructure (AMI): Systems that measure, collect and analyze energy
usage, from advanced devices such as electricity meters, natural gas meters and/or water meters
through various communication media on request or on a predetermined schedule.
advisory group:Avista's group of external interested persons and efficiency program experts who
advise on the company's planned energy efficiency activities, as well as activities under
consideration.
Air-Conditioning, Heating, and Refrigeration Institute (AHRI): The trade association
representing manufacturers of HVAC and water heating equipment within the global industry.
aMW: 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 National Standards Institute (ANSI): A source for information on national, regional,
and international standards and conformity assessment issues.
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 Report (ACR): An Avista-prepared resource document that summarizes
its annual energy efficiency achievements.
Annual Fuel Utilization Efficiency (AFUE): A measurement on how efficient an appliance is in
converting the energy in its fuel to heat over the course of a typical year.
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, which would have occurred without
implementation of the subject energy efficiency activity. Baseline conditions are sometimes
referred to as "business-as-usual" conditions.
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 energy 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 the
energy efficiency activity takes place.
Business Partner Program (BPP): An outreach effort designed to raise awareness of utility
programs and services that can assist small business customers in managing their energy bills.
British Thermal Unit(Btu):The amount of heat energy necessary to raise the temperature of one
pound of water one degree Fahrenheit (3,413 Btu are equal to one kilowatt-hour).
61

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 is capable of carrying
under specified conditions.
Community Action Agency (CAA): An agency (local nonprofit or public organization) that
provides programs and services to help low-income individuals and families achieve self-
sufficiency and overcome poverty.
Community Action Partnership (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 agencies and other funding sources (e.g. utility
constitutions).
conservation:According to the Northwest Power Act, any reduction in electric power consumption
as a result 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 Integrated Resource Planning (IRP) process.
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.
customer/customer classes:A category, or categories, of customers 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.
deemed savings: Primarily referenced as unit energy savings, 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, expressed in cubic feet, therms, Btu or multiples
thereof, for a designated period of time such as during 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 means using less while still having
the same useful output of function.
62

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.
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.
end-use:A term referring to the final use of energy; it often refers to the specific energy services
(for example, space heating), or the type of energy-consuming equipment (for example, motors).
Energy Efficiency Advisory Group (EEAG): A group which advises investor-owned utilities on
the development of integrated resource plans and conservation programs.
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."
evaluation: The performance of a wide range of assessment studies and activities aimed at
determining the effects of a program (and/or portfolio)and understanding or documenting program
performance, program or program-related markets and market operations, program-induced
changes in energy efficiency markets, levels of demand or energy savings, or program cost-
effectiveness. Market assessment, monitoring and evaluation, and verification are aspects of
evaluation.
Evaluation, Measurement, and Verification (EM&V): Catch-all term for evaluation activities at
the measure, project, program and/or portfolio level; can include impact, process, market and/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."
external evaluators (i.e., third-party evaluators): Independent professional efficiency person or
entity retained to conduct EM&V activities. Consideration will be made for those who are Certified
Measurement and Verification 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.
gross savings: The change in energy consumption and/or demand that results from energy
efficiency programs, codes and standards, and naturally occurring adoption which have a long-
lasting savings effect, regardless of why they were enacted.
63

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 ductless heat pump equipment.
Heating, Ventilation, and Air Conditioning (HVAC): Sometimes referred to as climate control,
the HVAC is particularly important in the design of medium to large industrial and office buildings
where humidity and temperature must all be closely regulated whilst maintaining safe and healthy
conditions within.
HOU: Hours of use (an annual estimation of lighting or HVAC equipment operation hours).
Idaho Public Utilities Commission (1PUC): Regulators of investor-owned or privately owned
utilities that provide natural gas, water, electricity, or some telephone services for profit.
impact evaluation: Determination of the program-specific, directly or indirectly induced changes
(e.g., energy and/or demand usage) attributable to an energy efficiency program.
implementer: Avista employees 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.
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 commissions 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 (www.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 one pound of water one degree
Fahrenheit; the prefix kilo- stands for 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,
64

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 levelizing 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.
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 of a single piece of equipment,
subsystem or system, or single modification of equipment, subsystem, system, or operation at an
end-use energy consumer facility, for the purpose of reducing energy and/or demand (and, hence,
energy and/or demand 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 that is 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, and/or computer
simulation modeling. M&V approaches are defined in the International Performance Measurement
and Verification Protocol (IPMVP available at www.evo-world.org).
Megawatt (MW): The electrical unit of power that equals one million watts or one thousand
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 and/or demand that is attributable to an energy
efficiency program. This change in energy use and/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 and/or in adjustments to gross savings values.
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 environment
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
65

supplies capital to a customer to fund energy efficiency, renewable energy, or other generation
projects. It is repaid through regular payments on an existing utility bill.
Participant Cost Test(PCT):The PCT measures quantifiable costs and benefits to the customer
participating in a program. 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, 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 for 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 Northwest Power and Conservation Council established in
1999 to develop standards to verify and evaluate energy efficiency savings.
realization rate: 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(1)
ex-ante gross reported savings to ex-post gross evaluated savings, or (2) 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
66

savings will be based on best available information.
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. These are the residential,
commercial (e.g., retail stores, office and institutional buildings), industrial, and agriculture (e.g.
dairy farms, irrigation) sectors.
service territory:The areas in Idaho, Washington, and Oregon served by Avista to provide either
natural gas or electric service (or both).
Site-Specific (SS): 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, nor other investment
opportunities.
spillover:Reductions in energy consumption and/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 and/or non[participant
spillover (sometimes referred to as "free drivers"). Participant spillover is the additional energy
savings that occur as a result 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 as a result of a program's influence.
Technical Reference Manual (TRM): An Avista-prepared resource document that contains
Avista's (ex-ante)savings estimates, assumptions, sources for those assumptions, guidelines, and
relevant supporting documentation for its natural gas and electricity energy efficiency prescriptive
measures. This is populated and vetted by the RTF and third-party evaluators.
Total Resource Cost(TRC):A cost-effectiveness test that assesses the impacts of a portfolio of
67

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.
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 a majority of the high-voltage, long-distance transmission lines.
Uniform Energy Factor(UEF):A measurement of how efficiently a water heater utilizes its fuel.
Unit Energy Savings (UES): Defines the 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 1
divided by the R-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 benefit is 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 electro-mechanical 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 the program
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, and/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. It may include review of
commissioning or retro-commissioning documentation. Verification 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.
Weighted Average Cost of Capital(WACC):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.
68

8,760: Total number of hours in a year.

Appendices and Supplements
Appendix A— 2025 Electric Impact Evaluation Report
Appendix B — 2025 Natural Gas Impact Evaluation Report
Appendix C — 2025 Cost-Effectiveness Tables
Appendix D — 2025 Expenditures by Program
Appendix E — 2025 Energy Efficiency Activity by Program
Appendix F — NEEA 2025 Annual Savings Report — Electric
Appendix G — NEEA 2025 Annual Savings Report — Natural Gas
Appendix H — NEEA 2025 Annual Savings Report Addendum
Appendix I — List of 2025 EEAG Meetings and Topics

Appendix A: 2025 Electric Impact Evaluation Report

Impact Evaluation of Avista
Utilities' Idaho Electric
PY2025 Residential , Low
Income, and Non Residential
Energy Efficiency Programs
Submitted By: Qualus
Submitted On: April 15, 2026
Submitted To: Avista Utilities
Qualus Avista Utilities
100 Colonial Center Parkway, Suite 400 1411 E. Mission Ave.
Lake Mary, FL 32746 Spokane, WA 99252

Avista Idaho Electric PY2025 Qualus
Table of Contents
1. Executive Summary..............................................................................................................................6
1.1 Savings Results............................................................................................................................................6
1.2 Conclusions and Recommendations...........................................................................................................7
2. General Methodology........................................................................................................................13
2.1 Glossary of Terminology...........................................................................................................................13
2.2 Summary of Approach..............................................................................................................................14
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..............................................................................................48
4.1 Simple Verification Results.......................................................................................................................48
4.2 Program-Level Impact Evaluation Results................................................................................................50
5. Non Residential Impact Evaluation Results........................................................................................54
5.1 Database& Document Verification..........................................................................................................55
5.2 Survey Verification....................................................................................................................................55
5.3 Program-Level Impact Evaluation Results................................................................................................56
6. Appendices.........................................................................................................................................82
6.1 Appendix A: Billing Analysis Results.........................................................................................................82
6.2 Appendix B:Site Specific M&V Plans and Supplementary Information...................................................83
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List of Tables
Table 1-1: Residential Verified Impact Savings by Program .........................................................................6
Table 1-2: Low Income Verified Impact Savings by Year..............................................................................6
Table 1-3: Non Residential Verified Impact Savings by Program..................................................................7
Table 2-1: Document-based Verification Samples and Precision by Program ...........................................18
Table 2-2: Survey-Based Verification Sample and Precision by Program...................................................19
Table 3-1: Residential Verified Impact Savings by Program .......................................................................28
Table 3-2: Residential Costs by Program ....................................................................................................28
Table 3-3: Residential ISRs by Measure......................................................................................................29
Table 3-4: Appliances Program Measures ..................................................................................................30
Table 3-5:Appliances Program Verified Electric Savings............................................................................31
Table 3-6:Appliances Program Costs by Measure .....................................................................................31
Table 3-7: ENERGY STAR° Homes Program Measures ...............................................................................33
Table 3-8: ENERGY STAR' Homes Program Verified Electric Savings.........................................................33
Table 3-9: ENERGY STAR° Homes Program Costs by Measure...................................................................33
Table 3-10: Fuel Conversion Program Measures........................................................................................35
Table 3-11: Fuel Conversion Program Verified Electric Savings .................................................................35
Table 3-12: Fuel Conversion Program Costs by Measure...........................................................................35
Table 3-13: Home Energy Audit Program Verified Electric Savings............................................................37
Table 3-14: Home Energy Audit Program Billing Analysis Results..............................................................38
Table 3-15: Home Insulation Program Measures.......................................................................................39
Table 3-16: Home Insulation Program Verified Electric Savings.................................................................39
Table 3-17: Home Insulation Program Costs by Measure ..........................................................................39
Table 3-18: Midstream Program Measures................................................................................................41
Table 3-19: Midstream Program Verified Electric Savings..........................................................................42
Table 3-20: Midstream Program Incentive Costs by Measure ...................................................................42
Table 3-21: Shell Program Measures..........................................................................................................44
Table 3-22: Shell Program Verified Electric Savings....................................................................................45
Table 3-23: Shell Program Costs by Measure.............................................................................................45
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Avista Idaho Electric PY2025 Qualus
Table 4-1: PY2025 Low Income Verified Impact Savings by Program Year.................................................48
Table 4-2: PY2025 Low Income Costs by Program Year..............................................................................48
Table 4-3: Low Income Program Measures ................................................................................................50
Table 4-4: PY2024 Low Income Program Claimed Electric Savings ............................................................51
Table 4-5: PY2024 Low Income Program Claimed Costs by Measure ........................................................51
Table 4-6: PY2025 Low Income Program Claimed Electric Savings ............................................................52
Table 4-7: PY2025 Low Income Program Claimed Costs by Measure ........................................................52
Table 5-1: Non Residential Verified Impact Savings by Program................................................................54
Table 5-2: Non Residential Costs by Program.............................................................................................54
Table 5-3: Prescriptive Lighting In-Service Rates........................................................................................55
Table 5-4: Building Operator Certification Program UES Sources..............................................................56
Table 5-5: BOC Program Verified Electric Savings ......................................................................................56
Table 5-6: BOC Program Costs by Measure................................................................................................57
Table 5-7: Green Motors Program Measures.............................................................................................58
Table 5-8: Green Motors Program Verified Electric Savings.......................................................................58
Table 5-9: Green Motors Program Costs by Measure................................................................................58
Table 5-10: Grocer Program Measures.......................................................................................................60
Table 5-11: Grocer Program Verified Electric Savings................................................................................60
Table 5-12: Grocer Program Costs by Measure..........................................................................................60
Table 5-13: Grocer Verification Precision...................................................................................................61
Table 5-14: Non Residential Midstream Program Measures......................................................................62
Table 5-15: Non Residential Midstream Program Verified Electric Savings...............................................63
Table 5-16: Non Residential Midstream Program Costs by Measure.........................................................63
Table 5-17: Prescriptive Lighting Program Measures.................................................................................65
Table 5-18: Prescriptive Lighting Program Verified Electric Savings...........................................................65
Table 5-19: Prescriptive Lighting Program Costs by Measure ....................................................................67
Table 5-20: Small Business Lighting Program Measures.............................................................................70
Table 5-21: Small Business Lighting Program Verified Electric Savings......................................................71
Table 5-22: Small Business Lighting Program Costs by Measure................................................................72
Table 5-23: Non Residential Shell Program Measures................................................................................75
Table 5-24: Non Residential Shell Program Verified Electric Savings.........................................................75
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Avista Idaho Electric PY2025 Qualus
Table 5-25: Non Residential Shell Program Costs by Measure...................................................................75
Table 5-26: Non Residential Shell Program Verification Precision.............................................................76
Table 5-27: Site-Specific Program Verified Electric Savings........................................................................78
Table 5-28: Site-Specific Program Costs .....................................................................................................78
Table 5-29: Site-Specific Program Sample Design ......................................................................................79
Table 5-30: Site-Specific Expected,Adjusted and Verified kWh Savings by Sampled Project....................80
Table 6-1: Regression Savings, Home Energy Audit Program.....................................................................82
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1. Executive Summary
This report is a summary of the impact evaluation of Avista Utilities' (Avista) 2025 program year
(PY2025) Residential, Low Income, and Non Residential Electric Energy Efficiency Portfolio in the
Idaho service territory.The evaluation, measurement, and verification (EM&V) of PY2025 Idaho
Electric portfolio was administered by Qualus, a leading pure-play power services firm. (herein
referred to as the "Evaluators").
1.1 Savings Results
The Evaluators conducted an impact evaluation of Avista's Residential, Low Income, and Non
Residential programs for PY2025.The verified Residential portfolio savings amounted to
2,635,481.73 kWh with a 98.09% realization rate.The PY2025 verified Low Income portfolio savings
amounted to 142,111.79 with a 54.20% realization rate. Of note,the Evaluators also assessed
PY2024 savings associated with the Low Income program. The PY2025 Non Residential portfolio
savings amounted to 32,678,682.11 kWh with a 100.70% realization rate.The Evaluators summarize
the Residential, Low Income, and Non Residential portfolio verified savings in Table 1-1 through
Table 1-3, respectively.
Table 1-1: Residential Verified Impact Savings by Program
Project Expected Verified Realization Incentive
Program Count Savings Savings Rate Costs
Appliances 569 106,215.00 26,381.67 24.84% $45,552.70
ENERGY STAR Homes 12 39,487.00 44,242.97 112.04% $12,000.00
Fuel Conversion 11 90,844.00 82,405.74 90.71% $26,100.00
Home Energy Audit 108 0.00 86,914.01 NA $0.00
Home Insulation Program 8 11,327.14 11,436.27 100.96% $8,754.00
Residential Midstream 1,147 2,231,462.71 2,234,476.95 100.14% $560,250.00
Residential Shell 234 207,488.24 149,624.12 72.11% $239,104.50
Residential Total 2,089 2,686,824.08 2,635,481.73 98.09% $891,761.20
Table 1-2:Low Income Verified Impact Savings by Year
Program Expected Verified Realization Incentive
Year Project Count Savings Savings Rate Costs
(therms) (therms)
2024 64 64,877.67 45,074.37 69.48% $213,699.98
2025 124 262,202.29 142,111.79 54.20% $842,001.56
Total 188 327,079.96 187,186.16 57.23% $1,055,701.54
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Table 1-3:Non Residential Verified Impact Savings by Program
Program Project Expected Verified Realization Incentive Costs
Count � Savings(kWh) Savings(kWh) Rate
Building Operator Certification 1 0.00 119,000.00 NA $0.00
Green Motors 2 10,529.00 7,625.21 72.42% $1,400.00
Grocer 1 2,919.00 2,918.58 99.99% $300.00
Non Residential Midstream 69 163,821.00 163,691.23 99.92% $74,140.00
Prescriptive Lighting 471 3,818,500.45 3,900,750.23 102.15% $835,378.12
Small Business Lighting 1,924 18,592,355.85 18,962,968.96 101.99% $10,726,871.91
Non Residential Shell 2 14,280.42 10,120.54 70.87% $13,883.38
Site Specific-Lighting 6 101,225.00 91,700.23 90.59% $19,639.61
Site Specific-Other 9 9,746,501.06 9,419,907.14 96.65% $1,952,256.22
Total 2,485 32,450,131.78 32,678,682.11 100.70% $13,623,869.24
Details on the varied methodologies used to calculate verified savings associated with each measure can
be found in the Residential, Low Income, and Non Residential program-level impact evaluation results
sections below.
1.2 Conclusions and Recommendations
The following section details the Evaluators' conclusions and recommendations for each the Residential,
Low Income, and Non Residential program evaluations.
1.2.1 Conclusions
Key program-specific and overarching conclusions are presented in the following subsections.
1.2.1.1 Residential Programs
The Evaluators provide the following conclusions regarding Avista's Residential electric programs:
The Evaluators found the Residential Portfolio had total verified savings of 2,635,481.73 kWh
with a realization rate of 98.09%. This suggests strong consistency in expected and verified
savings methodologies, particularly so for the Residential Midstream program which made up
over 84%of total verified residential savings.
The Appliances and Residential Shell programs yielded realization rates of 24.84%and 72.11%,
respectively. Lower realization rates for these programs were driven by differences in the
granularity of the Northwest Power and Conservation Council's Regional Technical Forum (RTF)
measure deemed savings estimates as compared to the expected values employed by Avista.
The RTF differentiates deemed savings values by a variety of factors including location (per RTF
heating/cooling zone), installed equipment efficiency(e.g., window U-factor, insulation R-value,
appliance ENERGY STAR most efficient certification), heating fuel (e.g., gas vs. electric), and
household heating equipment type (e.g., heat pump vs. electric furnace). In contrast, Avista's
expected savings values were more often averaged values with less differentiation by the
aforementioned factors. While less granularity in measure differentiation can make it more
straightforward to determine ex-ante savings, averaged values can be less precise than the RTF's
savings differentiation. This difference in deemed savings value differentiation was a key driver
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Avista Idaho Electric PY2025 Qualus
of lower realization rates. In addition to this difference in methodological granularity,the
Evaluators also found several instances in which installed equipment did not meet claimed
efficiency standards which also contributed to lower program-wide realization rates.
■ The ENERGY STAR Homes Program yielded a realization rate of 112.04% primarily due to
differences in savings methodologies for gas&electric manufactured homes.The ex-ante
methodology seemed to assign a prescriptive savings value to these households that averages
across RTF heating zones. In contrast, the Evaluators assigned savings based on the actual
location of customers' homes. Since many customers purchased homes in the RTF's Heating
Zone 3 (the coldest of the three heating zones),the verified savings were higher than the
expected savings yielding a realization rate slightly above 100%.
■ The Fuel Conversion Program yielded a realization rate of 90.71% primarily due to the fact that
two of the four water heaters included in the "E Electric to Natural Gas Furnace &Water Heat"
measure did not meet efficiency requirements. Outside of this issue, all other sampled measures
yielded a 100% realization rate.
■ The Home Energy Audit Program did not include expected savings and as such has no realization
rate; however,the program yielded 86,914.01 kWh in verified savings for an average of 804.76
kWh per household. This represents substantial electric energy savings and suggests that
customers participating in the Home Energy Audit program in PY2025 have made substantial
changes to their electric energy usage behavior as compared to 2024.
■ The Home Insulation Program yielded a realization rate of 100.96% highlighting how verified
savings estimates matched expected savings estimates very closely.The non-100% realization
rate was due to slight differences in how Avista and the Evaluators applied the RTF's LIES savings
values for attic insulation.
■ The Residential Midstream Program yielded verified savings of 2,234,476.95 kWh with a
realization rate of 100.96%. Across 2024 and 2025 the Evaluators have collaborated with Avista
to review and verify the methodologies used to develop the midstream section of Avista's TRM.
This realization rate of close to 100% highlights Avista's accurate application of reviewed savings
values across the Midstream program.
1.2.1.2 Low Income Programs
The Evaluators provide the following conclusions regarding Avista's Low Income electric programs:
■ In 2025 the Evaluators conducted evaluations for the PY2024 and PY2025 Low Income Program.
In PY2024,the Low Income Program displayed verified savings of 142,111.79 with a 54.20%
realization rate. In PY2025,the Low Income Program displayed verified savings of 45,074.37
kWh with a 69.48% realization rate.The lower realization rate was primarily explained by
differences in the granularity of Avista expected deemed savings methodologies and RTF
deemed savings values per unit energy savings workbooks. In addition to RTF deemed savings
estimates being more granular, Low Income tracking data and documentation often was missing
key measure information which required the Evaluators to make assumptions regarding factors
like heating equipment type and the difference between baseline and installed equipment
efficiency.
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Avista Idaho Electric PY2025 Qualus
1.2.1.3 Non Residential Programs
The Evaluators provide the following conclusions regarding Avista's Non Residential electric programs:
■ The Evaluators found the Non Residential portfolio had total verified savings of 32,678,682.11
kWh with a realization rate of 100.70%. All programs except for the Green Motors and Non
Residential Shell programs had realization rates between 90%and 105%.The Green Motors
program had a realization rate of 72.42%while the Non Residential Shell program had a 70.89%
realization rate. Broadly there was good consistency between expected and verified savings for
the Non Residential portfolio.
■ The Building Operator Certification program did not yield a realization rate due to no expected
savings being claimed; however, the Evaluators identified 119,000.00 kWh verified savings
associated with the program.
■ The Green Motors program yielded a realization rate of 72.42% primarily due to different
assumptions regarding the efficiency improvements associated with motor rewinds between the
Avista TRM and the RTF UES workbook. Avista's expected savings were 4,535.00 kWh and
5,994.00 kWh for a 300 and a 400 HP motor, respectively. In contrast,the RTF suggests savings
of 3,284.11 kWh for the former and 4,341.10 for the latter.
■ The Grocer and Non Residential Midstream program yielded realization rates of 99.99%and
99.92%suggesting excellence consistency between expected and verified savings
methodologies. Slight differences in assumptions regarding equipment capacity and rounding
differences led to realization rates slightly lower than 100%; however, broadly these programs
seem to have yielded savings almost identical to Avista's expected savings estimates.
■ The Prescriptive Lighting and Small Business Lighting programs had realization rates of 102.15%
and 101.99% primarily due to differences in assign facility type which affects assumed hours of
use and calculated lighting savings. Broadly, expected and verified savings matched closely for
both of these programs.
■ The Non Residential Shell Program had a realization rate of 70.87%.This lower realization rate
is explained by the fact that the Evaluators employed an engineering equation with weather
inputs specific to Sandpoint, ID to assess measure savings.The integration of actual 2025
weather data into the verified analysis likely contributed to lower savings values than
generalized estimates used by Avista for expected savings.
■ The Site Specific program yielded an overall realization rate of 96.59%, suggesting strong
consistency in ex-ante and ex-post evaluation methodologies across most custom projects. In
several instances, expected savings methodologies could not be reverse engineered with
available documentation and as such the Evaluators employed a different analysis methodology
(e.g., a billing analysis)to assess project savings. In a few cases these alternative analysis
methodologies yielded lower verified savings than expected which contributed to a realization
rate slightly less than 100%.
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Avista Idaho Electric PY2025 Qualus
1.2.2 Recommendations
Key program-specific and overarching recommendations are presented in the following subsections.
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.
■ The Evaluators also found several instances in which RTF heating zone or household heating fuel
included in the tracking data did not match rebate documentation. The Evaluators would
recommend Avista regularly review tracking data and compare it to available databases to
improve accuracy where possible.
■ In addition,there were many instances in which Avista's expected savings values did not align
with the more granular estimates included in RTF unit energy savings workbooks.The Evaluators
appreciate there is a balance between the ease of applying a single savings value to an installed
measure and the improved precision of differentiating savings based on a variety of factors.
However, at a minimum the Evaluators would recommend differentiating savings based on
location (e.g.,via RTF heating/cooling zone) and measure efficiency in the future to ensure
expected savings values are as precise as possible.
■ Lastly,the Evaluators would suggest Avista include key fields in tracking data across all
programs. Certain fields are always used in savings evaluation and without them simplifying
assumptions are often required which may reduce the accuracy of savings estimates.The
Evaluators appreciate that customers may not completely fill out rebate application forms,
which may make tracking data completeness a challenge; however, tracking data should ideally
include the following fields at a minimum:
o A unique identifier for each measure installed
o Household space heating fuel and equipment type (e.g., heat pump vs. electric furnace)
o Household water heating fuel and equipment type
o Household address including zip code
o Whether or not the household has cooling equipment
o Measure installation quantity and square footage for relevant measures like windows
and insulation
o Measure baseline conditions including efficiency and configuration (e.g., the type of
windows being replaced—single vs. double pane)
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Avista Idaho Electric PY2025 Qualus
o Installed measure equipment efficiency and configuration
o Installed measure equipment model numbers
o Expected savings estimates
o Incentive and measure costs associated with the installed equipment
1.2.2.2 Low Income Programs
The Evaluators offer the following recommendations regarding Avista's Low Income electric programs:
■ Within the Low Income Program,the Evaluators recommend prioritizing improvements to
tracking data completeness and consistency, particularly for heating type, measure quantities,
and measure-specific attributes, and enhancing data collection protocols to align more closely
with RTF input requirements, in order to reduce reliance on secondary data sources and
conservative assumptions in future impact evaluations.
1.2.2.3 Non Residential Programs
The Evaluators offer the following recommendations regarding Avista's Non Residential electric
programs:
■ The Evaluators found several instances in which RTF heating zone or household heating fuel
included in the tracking data did not match rebate documentation.The Evaluators would
recommend Avista regularly review tracking data and compare it to available databases to
improve accuracy where possible.
■ The Evaluators would suggest Avista include key fields in tracking data across all programs.
Certain fields are always used in savings evaluation and without them simplifying assumptions
are often required which may reduce the accuracy of savings estimates.The Evaluators
appreciate that customers may not completely fill out rebate application forms,which may
make tracking data completeness a challenge; however, tracking data should ideally include all
the fields detailed above in the Residential Programs recommendations section.
■ Particularly for measures related to facility heating and cooling (e.g., HVAC equipment and
weatherization),Avista should consider integrating real world weather data into analyses to
improve savings accuracy. Weather data can be integrated analyses in a variety of ways,
including billing analyses with Heating/Cooling Degree Day controls and engineering equations
with weather inputs. Especially given increasingly extreme weather patterns, integrating current
weather data into select measure analyses could help identify more accurate savings estimates
than deemed values.
■ For the Prescriptive Lighting Program, Avista should consider applying an in-service rate to
expected savings calculations. Particularly with lighting programs, in-service rates can vary from
100%, so it may be worthwhile to account for the fact that not all customers may install the
efficient lighting equipment they receive.
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Avista Idaho Electric PY2025 Qualus
■ For the Site Specific Program, the Evaluators would recommend Avista share expected savings
Excel calculators/tools wherever possible to ensure verified savings are calculated based on the
most complete information possible. While tracking data and rebate documentation PDFs both
provide useful details for verified savings calculations, given the complexity of some custom
measures, having access to all ex-ante Excel calculators would be useful for future savings
estimation.
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Avista Idaho Electric PY2025 Qualus
2. General Methodology
The Evaluators performed an impact evaluation on each of the programs in Avista's Idaho electric
portfolio.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:
■ Simple verification (web-based 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 for each the electric impacts and the natural gas
impacts for projects completed in the Idaho Avista service territory. For the purposes of this report, only
the Idaho Electric impacts are quantified and reported.
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 20134
■ International Performance Measurement and Verification Protocol (IPMVP) maintained by the
Efficiency Valuation Organization (EVO) with sponsorship by the U.S. Department of Energy
(DOE)5
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:
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 Qualus(formerly 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 Electric PY2025 Qualus
■ 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.
■ 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 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 Non Residential programs.The Evaluators start by presenting our
general evaluation approach.This chapter is organized by general task due to substantial overlap across
programs.
The Evaluators outline the approach to verifying, measuring, and reporting the residential portfolio
impacts as well as cost-effectiveness and 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 2026 program
year and onwards.
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 Electric PY2025 Qualus
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 and Small Business 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 may also be
employed, depending upon the project. Specific methods are discussed in each site report.
The Evaluators aimed to accomplish 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;
■ Where available data exists, conduct billing analysis with a suitable comparison group to
estimate measure savings; and
■ Use IPMVP analysis methods for custom projects.
The Evaluators calculated verified savings for each measure based on the RTF UES, Avista TRM, or an
IPMVP-approved methodology (such as an Option C billing analysis) in combination with the results from
document review. For the Appliances, ENERGY STAR Homes, Residential Shell, Green Motors, and
Prescriptive Lighting Programs,the Evaluators also applied in-service rates (ISRs)from verification
surveys.The following flow chart outlines the process by which the Evaluators progress from reported
savings to verified savings.
Reported Database Document Verified
Savings Review r 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.
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.
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Measure-level net savings were evaluated primarily by reviewing measure algorithms and values in the
tracking system to ensure appropriate, error-free savings estimates were included in the tracking data.
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 projects were
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
2.2.2.2 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 = (ZXCV)Z
d
Equation 2-2:Sample Size for Finite Population Size
n
no = (( ll
1 + `Nl
Where,
■ n =Sample size
■ Z =Z-value for a two-tailed distribution at the assigned confidence level.
■ CV = Coefficient of variation
■ d = Precision level
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■ 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.
2.2.2.3 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
that have 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.
2.2.2.4 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.
■ Appliances Program
■ ENERGY STAR' Homes Program
■ Home Insulation Program
■ Residential Midstream Program
■ Residential Shell Program
■ Low Income Program
6 Assumption based off California Evaluation Framework:
https://www.cpuc.ca.gov/uploaded Files/CPUC_Public_Website/Content/UtiIities_and_I ndustries/Energy/Energy_Programs/De
mand_Side_Management/EE_and_Energy_Savings_Assist/CAEvaluationFramework.pdf
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Green Motors Program
Grocer Program
Non Residential Midstream Program
Prescriptive Lighting Program
Small Business Lighting Program
Non Residential Shell Program
Site Specific 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 Database Review & Document Verification sections presented for
each program.
Meanwhile the Home Energy Audit and Building Operator Certification programs were evaluated based
on a comprehensive review of billing data, tracking data from current and previous evaluations, and key
whitepapers.
The Evaluators developed a sampling plan that aimed to achieve 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
ProgramSample
Sector
Adjustment)Population Population
Residential Appliances 569 65 90%±9.60%
Residential ENERGY STAR Homes 12 12 90%±0.00%
Residential Fuel Conversion 11 11 90%±0.00%
Residential Home Insulation 8 8 90%±0.00%
Residential Residential Midstream 1,018 577 90%±2.25%
Residential Residential Shell 234 56 90%±9.59%
Low Income Low Income 76 42 90%±8.49%
Non Residential Green Motors 2 2 90%±0.00%
Non Residential Grocer 1 1 90%±0.00%
Non Residential Non Residential Midstream 79 16 90%±9.22%
Non Residential Prescriptive Lighting 471 75 90%±8.72%
Non Residential Small Business Lighting 1,924 97 90%±8.06%
Non Residential Non Residential Shell 1 1 90%±0.00%
Non Residential Site Specific 1 15 1 7** 90%±6.48%
*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 Site-Specific Program sample is distinct from other sampling methodologies presented in this table as it is chosen via a
random stratified sample.However,it is included in this table for illustrative and informative purposes.
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The table above represents the number of rebates in Idaho service territory only(does not include Idaho
rebate samples). The Evaluators ensured representation of state and fuel type in the sampled rebates
for document verification.
2.2.2.5 Survey-Based Verification
The Evaluators conducted survey-based verification for the Appliances program, Residential Shell
program, and the Prescriptive Lighting program in PY2025.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 shown in Table 2-2 for the Residential Appliance and
Non Residential Lighting Programs.The Evaluators developed a sampling plan that achieved a sampling
precision of±4.62% at 90%statistical confidence for residential ISRs estimates at the program-level
during web-based survey verification. The Evaluators developed a sampling plan that achieved a
sampling precision of±7.94%at 90%statistical confidence for non-residential ISRs estimates at the
program-level during web-based survey verification.
Table 2-2:Survey-Based Verification Sample and Precision by Program
Population Precision at 90%Cl
Residential Appliances 2,911 160 90%±6.32%
Residential Shell 6,115 146 90%±6.73%
Non Residential Prescriptive Lighting 1,269 99 90%±7.94%
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. For all programs in which in-service rates were not identified via survey-based verification,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 in the calculation of verified savings values.
2.2.2.6 On-Site Visits
For the 2025 evaluation,the Evaluators did not conduct any on-site visits as available tracking data and
rebate documentation contained all required data for verification.
2.2.3 Impact Evaluation Methodology
The Evaluators employed the following approach to complete impact evaluation activities for all
programs except Site Specific.The Evaluators define two major approaches to determining net savings
for Avista's programs:
■ Deemed Savings
■ Partial Retrofit Isolation Engineering Equation (IPMVP Option A)
■ Billing Analysis (IPMVP Option C)
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In contrast, the Site-Specific program also employed various IPMVP options, based on available data and
the energy efficiency measures being installed.This approach is discussed separately in the Site Specific
Program section 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 the deemed savings and billing analysis approaches.
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. Per RTF UES workbook guidelines,the Evaluators differentiated
savings based on customer heating/cooling zone and other key measure/household data like equipment
efficiency and heating fuel type,where appropriate and available.
The Evaluators requested and used the technical reference manual Avista employed during calculation
of ex-ante measure savings (Avista TRM) for limited measures where an appropriate RTF UES measure
workbook (or other valid methodology) was not available. Of note, based on extensive discussions with
Avista and its Midstream program implementer,Avista TRM values were used to verify both Residential
and Non Residential Midstream measures.These midstream measure Avista TRM savings values were
thoroughly vetted by the Evaluators across 2024 and 2025.
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 Partial Retrofit Isolation Engineering Equation
For select measures where an RTF UES measure workbook was not available,the Evaluators employed
simple engineering equations to identify measures savings.This methodology is consistent with IPMVP
Option A partial retrofit isolation. Valid engineering equations were identified using reputable sources
such as the Illinois TRM version 12.'Wherever possible, Pacific Northwest-specific inputs were used in
these engineering equations to ensure verified savings estimates were regionally relevant.
2.2.3.3 Billing Analysis
This section describes the billing analysis methodology employed by the Evaluators as part of impact
evaluation activities. In most cases,the Evaluators performed billing analyses with a matched control
group, utilizing 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 necessary to produce a matched control
7 https://www.ilsag.info/wp-content/uploads/IL-TRM-Version-12.0-Volumes-1-4-Compiled-Final.pdf
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cohort. Where a valid matched control group could not be developed,the Evaluators employed a
treatment-only regression analysis.
For the purposes of this analysis, a household is considered a treatment household if it has participated
in an energy efficiency program. Meanwhile, a household is considered a control household if the
household has not participated in an energy efficiency program during the relevant analysis period.To
isolate measure impacts,treatment households are eligible to be included in the billing analysis if they
installed only one measure during the 2025 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 feasible to identify.Therefore,
instances where households installed isolated single measures were used in the billing analyses.
Before delving further into the specifics of the Evaluators' billing analysis methodology, it is important to
clarify a few key definitions. In the context of a billing analysis, the pre-period identifies the period prior
to measure installation while the post-period refers to the period following measure installation. In the
regressions run by the Evaluators the pre-period and the post-period were both 12 months meaning the
overall analysis period was 24 months.
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 as well as other variables like 3-digit zip code.
Similarity between treatment customers and matched controls can be verified via statistical difference
testing. After developing a matched cohort via PSM,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 comparable 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 perfectly matched control group, the inclusion of a
control group via PSM allows billing analyses to control for external factors that might affect energy
usage. Some examples of external factors that might impact energy usage include changes in the
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economy(e.g., a recession), large-scale societal changes (e.g., a pandemic), or major weather-related
anomalies such as flooding or hurricanes. If such external factors are not present,then a treatment-only
regression analysis can also be a valid methodology to determine measure-level savings.
After PSM,the Evaluators ran the following regression models for each measure included in the billing
analysis:
■ 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)
After running these regressions,the Evaluators determined the most appropriate model base on a
review of key metrics such as model fit (per adjusted R-squared), model significance (i.e., a p-value<_
0.05), and average savings values. 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
4. National Oceanic and Atmospheric Administration (NOAA) weather data between January 1,
2024 and December 31, 2025)
5. Typical Meteorological Year(TMY3) data
Billing and weather data were obtained for program year 2025 and for one year prior to measure install
dates (2024).
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 a given program and installed a given
measure.
2. Excluded participant homes that also participated in other programs or installed other energy
efficiency measures.
8 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 any energy efficiency
programs.
4. Excluded bills missing address information, if any were identified.
5. Removed bills missing fuel type/Unit of Measure (UOM) information, if any were identified.
6. Removed bills missing usage, billing start date, or billing end date, if any were identified.
7. Remove bills with outlier durations (<9 days or>60 days) , if any were identified.
8. Excluded bills with consumption indicated to be outliers, if any were identified.
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 02/19/2025 start date,
overlapping bill 2 had a 02/25/2025 start date, and the previous bill had a 02/19/2025 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 (this involves recalculating 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 the 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.
For this analysis the Evaluators assigned a setpoint of 65°F for both HDD and CDD.
13. Removed measure cohorts without at least 75 treatment customers.
14. Selected treatment customers with only one measure installed during the analysis period and
added measure install dates to the billing data dataset (to define pre-and post-periods).
15. Removed customers with incomplete post-period billing data (<6 months).
16. Removed customers with incomplete pre-period billing data (<10 months).
17. Restricted control customers to those with usage that was comparable with the treatment
group usage.
18. 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. In most cases, the Evaluators selected either Model 1 or Model 2
to identify verified net savings. However,the Evaluators also considered Model 3 since treatment-only
regression analyses can also provide valid savings estimates, especially if major external factors (e.g., a
pandemic) are unlikely to affect broader trends of customer energy usage (as is the case in Idaho across
2024 and 2025).
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Model 1:Fixed Effects Difference-in-Difference Regression Model
The following equation displays the first model specification used to estimate the average daily savings
associated with each energy efficiency measure included in the billing analysis.
Equation 2-3:Fixed Effects Difference-in-Difference (D-n-D)Model Specification
ADCit = ao +#1(Post)it +f32(Post x Treatment)it +f33(HDD)it +f34(CDD)it
+f s(Post x HDD)it +&(Post x CDD)it +f34Post x HDD x Treatment)it
+f3$(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
■ 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.f32 represents the average change in daily usage in the post-period between
the treatment and control group and N7 and Qs 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 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 = f32 * 365.25 +f37 * TMY HDD +f38 * TMY CDD
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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 +N2 (PreUsageSpring)i +f33(PreUsageSummer)i
+f34(PreUsageFa11)i +f35(PreUsageWinter)i + &(Month)t
+f37(Month x PreUsageSpring)it + &(Month x PreUsageSummer)it
+f g(Month x PreUsageFall)it +f310(Month x PreUsageWinter)it +Q11(HDD)it
+f312(CDD)it +f313(Treatment x HDD)it +f314(Treatment x CDD)it + £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
■ 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
■ 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
■ f31_14 = Coefficients determined via regression
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The coefficient N1 represents the average change in consumption between the pre-period and post-
period for the treatment group and R13 and F'14 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 N13 and!'14 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 +f313 * TMY HDD +F'14 * 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,treatment-only regression analyses (i.e.,those not
including a counterfactual comparison group) can also be an extremely useful tool for estimating energy
savings. One advantage of a treatment-only regression is it does not rely on quasi-experimental
methods (i.e., PSM)to develop a control cohort. Depending on available non-participant billing data, it
can be difficult to develop a valid matched control cohort. Especially if sufficient non-participant data is
not available to develop an appropriate control group,gross savings calculated via a treatment-only
regression can provide valid measure-level energy savings estimates. A treatment-only regression
analysis does not include control group billing data, instead it focuses exclusively on the differences in
energy usage between the pre-period and post-period for program participants.
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 +f31(Post)it +fj2(HDD)it +fj3(CDD)it +f34(Post X HDD)it +fjs(Post X CDD)it
+&(Customer Dummy)i +f37(Month)t + 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
■ 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)
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■ 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
■ £it = Customer-level random error
■ ao=The model intercept for home i
■ /31_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.
2.2.4 Net-To-Gross
The Pacific Northwest RTF UES measures do not require Net-To-Gross (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, do not require a NTG adjustment, as the counterfactual
represents the efficiency level at the current market (i.e.the efficiency level the customer would have
installed had they not participated in the program).
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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 PY2025. The following sections summarize electric impact
evaluation findings for 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 Verified Savings
Program r-F4jZct Coun'T (kWh) (kWh) Realization Rate
Appliances 569 106,215.00 26,381.67 24.84%
ENERGY STAR Homes 12 39,487.00 44,242.97 112.04%
Fuel Conversion 11 90,844.00 82,405.74 90.71%
Home Energy Audit 108 0.00 86,914.01 NA
Home Insulation Program 8 11,327.14 11,436.27 100.96%
Residential Midstream 11147 2,231,462.71 2,234,476.95 100.14%
Residential Shell 234 207,488.24 149,624.12 72.11%
Residential Total 2,089 2,686,824.08 2,635,481.73 98.09%
The following table presents residential incentive and measures costs by program. As outlined in the
following program-specific sections, in some cases tracking data did not include complete measure cost
information and if that was the case,the Evaluators assumed measure costs were identical to electric
incentive costs. For the Home Energy Report program, no cost information was included in the tracking
data and as such incentive and measure costs were assumed to be $0.00.
Table 3-2: Residential Costs by Program
Appliances $45,552.70 $770,106.08
ENERGY STAR Homes $12,000.00 $789,265.10
Fuel Conversion $26,100.00 $146,085.27
Home Energy Audit $0.00 $0.00
Home Insulation Program $8,754.00 $31,828.78
Residential Midstream $560,250.00 $560,250.00
Residential Shell $239,104.50 $2,450,166.09
Residential Total $891,761.20 $4,747,701.32
3.1 Simple Verification Results
The Evaluators surveyed customers participating in Avista's PY2025 Appliances and Residential Shell
program and received sufficient responses to hit 90/10 precision. Details on program populations and
survey responses can be found in the Survey-Based Verification section above. Results and findings from
these surveys and other process evaluation activities can be found in the Evaluators' separate process
report. For the purposes of this impact report, the key finding from this survey-based verification activity
is the identification of in-service rates.
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3.1.1 In-Service Rates
The Evaluators calculated in-service rates (ISRs) of installed measures from simple verification surveys
deployed to program participants in the Appliances and Residential Shell programs.The Evaluators
asked participants if the rebated equipment is currently installed and working. Measure-specific in-
service rates for the Idaho service territory can be found in the following table. The Evaluators assumed
an in-service rate of 100%for any measures not included in the following table.
Table 3-3:Residential ISRs by Measure
r Measure .. Methodology
ENERGY STAR Clothes Washer 15 100% Verification survey
Appliances ENERGY STAR Clothes Dryer 17 100% Verification survey
ENERGY STAR Freezer/Refrigerator 34 100% Verification survey
Glass Door 20 100% Verification survey
Shell Insulated Door 7 100% Verification survey
Windows 59 100% Verification survey
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 survey responses are included in a separate process
analysis report.
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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 Appliances Program
The Appliances Program is a residential prescriptive program that offers incentives for customers to
upgrade their existing clothes washers/dryers, refrigerators/freezers, and smart thermostats to ENERGY
STAR-rated products. Primary multifamily homes with shared interior walls including apartments,
duplexes, townhomes, and condos have no minimum usage requirement. Seasonal and recreational
homes are not eligible.
This section summarizes the impact results of the evaluation results for the Appliances Program. Table
3-4 summarizes the measures offered under this program.
Table 3-4:Appliances Program Measures
- Tescription Impact Analysis
40, 1 Methodology
E Energy Star Certified Refrigerator ENERGY STAR-certified refrigerator or
and Refrigerator-Freeze refrigerator with freezer for residential Billing Analysis
homes
E Energy Star Certified Upright ENERGY STAR-certified standard or compact RTF UES
Freezer freezers 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 ENERGY STAR-certified front-loading clothes RTF UES
Washer washer for residential homes
E Smart Thermostat DIY with Electric ENERGY STAR-certified Smart Thermostat RTF UES
Heat with DIY install for residential homes
E Smart Thermostat Paid Install with ENERGY STAR-certified Smart Thermostat RTF UES
Electric Heat with Paid Install for residential homes
Multifamily E Energy Star Certified ENERGY STAR-certified refrigerator or
Refrigerator and Refrigerator-Freeze refrigerator with freezer for residential RTF UES
homes
Multifamily E Energy Star Certified ENERGY STAR-certified standard or compact RTF UES
Upright Freezer freezers for residential homes
Multifamily E Energy Star Rated ENERGY STAR-certified clothes dryer for RTF UES
Clothes Dryer residential homes
Multifamily E Energy Star Rated ENERGY STAR-certified front-loading clothes RTF UES
Front Load Washer washer for residential homes
Multifamily E Smart Thermostat Paid ENERGY STAR-certified Smart Thermostat RTF UES
Install with Electric Heat with Paid Install for residential homes
The following table summarizes the verified electric energy savings for the Appliances Program impact
evaluation.
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Table 3-5:Appliances Program Verified Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
E Energy Star Certified Refrigerator and Refrigerator- 288 35,836.00 2,385.41 6.66%
Freeze
E Energy Star Certified Upright Freezer 32 2,278.00 881.05 38.68%
E Energy Star Rated Clothes Dryer 120 35,453.00 6,357.51 17.93%
E Energy Star Rated Front Load Washer 85 10,320.00 12,595.80 122.05%
E Smart Thermostat DIY with Electric Heat 21 16,478.00 3,157.72 19.16%
E Smart Thermostat Paid Install with Electric Heat 4 2,996.00 733.62 24.49%
Multifamily E Energy Star Certified Refrigerator and 16 1,984.00 112.92 5.69%
Refrigerator-Freeze
Multifamily E Energy Star Rated Clothes Dryer 3 870.00 157.62 18.12%
Total 569 106,215.00 26,381.67 24.84%
The Appliances Program displayed verified savings of 26,381.67 kWh with a realization rate of 24.84%
against the expected savings for the program. The following table summarizes the incentive and
measure costs associated with the program.
Table 3-6:Appliances Program Costs by Measure
Measure Incentive F Measure
costs Costs
E Energy Star Certified Refrigerator and Refrigerator-Freeze $28,800.00 $509,731.15
E Energy Star Certified Upright Freezer $1,700.00 $37,311.95
E Energy Star Rated Clothes Dryer $6,050.00 $112,122.90
E Energy Star Rated Front Load Washer $4,300.00 $84,240.87
E Smart Thermostat DIY with Electric Heat $2,352.70 $2,988.83
E Smart Thermostat Paid Install with Electric Heat $600.00 $1,273.09
Multifamily E Energy Star Certified Refrigerator and Refrigerator-Freeze $1,600.00 $20,062.33
Multifamily E Energy Star Rated Clothes Dryer $150.00 $2,374.96
Total $45,552.70 $770,106.08
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for Appliances Program in the section below.
3.2.1.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Appliance
Program.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Section 2.2.2.4.
The rebate application form aims to collect all required RTF measure specification details.The
Evaluators were able to verify the models for RTF specifications for most projects. One sampled electric
project did not include rebate data. Additionally, although model number is a required input, four
sampled projects did not include this information in the rebate application and therefore did not qualify
for measure savings. Lastly, one sampled project included a model that does not qualify for measure
savings in accordance with the RTF. In total, six sampled projects with claimed electric savings did not
meet the minimum requirements to qualify for RTF savings.
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3.2.1.2 Impact Analysis Savings Verification Findings
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 goals for the program were finalized.The Evaluators also conducted a billing analysis for all
measures with enough participation.The billing analyses did not yield statistically significant savings for
the Idaho population meaning the Evaluators employed RTF UES deemed savings values to calculate
verified savings.
As discussed above, six sampled electric projects did not meet the minimum requirements to qualify for
RTF savings due to model disqualification, missing model numbers in the rebate form, or missing rebate
data entirely. Five out of these six projects were for refrigerator/refrigerator-freezers, contributing to
low realization rates for that measure.
Verified savings resulted in a realization rate less than 100% largely due to low savings attributed to
refrigerator,freezer, clothes dryer, and smart thermostat measures.The RTF utilizes more inputs than
the Avista TRM to estimate deemed savings, including home characteristics like heat zone, heat type,
water heat type, and efficiency tiers for dryers, refrigerators, and freezers.After accounting for these
inputs,the magnitude of energy savings estimated by the TRM is only realized if the measure qualifies
for the RTF's highest tier of savings. Most sampled projects do not meet that highest tier and are instead
assigned significantly lower savings, particularly for electric appliances. For example, dryers must be
qualified according to the Northwestern Energy Efficiency Alliance (NEEA), while refrigerators and
freezers must be certified by Energy Star as Energy Star Most Efficient.Among 52 sampled projects, only
one met this highest efficiency level leading to realization rates of 6.66%, 38.68%, and 17.93%for
refrigerators, upright freezers, and electric dryers, respectively(single-family homes).
Electric smart thermostats, meanwhile, are estimated to save 749 kWh according to the TRM,whereas
the RTF estimates savings far less than 400 kWh unless the home is heated by an air source heat pump
with resistance optimization set up during installation. Furthermore,two of the five sampled
thermostats did not qualify for savings per RTF requirements,further reducing the total verified savings
for the measure.
Interestingly, electric front load washer measures displayed realization rates above 100%.The
Evaluators note that the RTF applies specific savings depending on the customer's home heat type and
hot water heat type, and including those inputs in the Avista TRM could realize higher savings for the
remaining electric appliance measures than as currently evaluated.
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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 incentivizes ENERGY STAR' Eco-rated
homes.Table 3-7 summarizes the measures offered under this program.
Table 3-7:ENERGY STAR Homes Program Measures
moor— Impact Analysis
Measure Description Methodology
G ENERGY STAR Home- ENERGY STAR-rated manufactured RTF UES
Manufactured,Gas Only home with natural gas
E ENERGY STAR Home-Manufactured, ENERGY STAR-rated manufactured RTF UES
Electric Only home with electric furnace
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 3-8:ENERGY STAR Homes Program Verified Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
E Energy Star Home-Manufactured, Electric Only 11 36,465.00 40,421.98 110.8551
E Energy Star Home-Manufactured,Gas& Electric 1 3,022.00 3,820.98 126.44%
Total I 12 39,487.00 I 44,242.97 112.04%
The ENERGY STAR' Homes Program displayed verified savings of 44,242.97 kWh with a realization rate
of 112.04% against the expected savings for the program. The following table summarizes the incentive
and measure costs associated with the program.
Table 3-9:ENERGY STAR Homes Program Costs by Measure
E Energy Star Home-Manufactured,Gas&Electric $11,000.00 $774,265.10
E Energy Star Home-Manufactured, Electric Only $1,000.00 $15,000.00
Total $12,000.00 $789,265.10
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.
3.2.2.1 Database Review& Document Verification
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 2.2.2.4.
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 sufficient
project documentation with the associated NEEM Certification.
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Avista Idaho Electric PY2025 Qualus
3.2.2.2 Impact Analysis Savings Verification Findings
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 goals for the program were 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. 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 112.04%with 44,242.97 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 ENERGY STAR' Homes Program deviates from 100% primarily due
discrepancies between Avista's TRM and the RTF with respect to energy savings associated with ENERGY
STAR' manufactured homes. As of PY2025, many manufactured homes were purchased in the RTF's
Heating Zone 3 which has higher deemed savings than Heating Zone 1 or Heating Zone 2. Ultimately,
categorical differences between the applied Avista TRM prescriptive savings value and the more detailed
RTF UES categories also caused realization rates to be slightly higher than 100%.
The realization rate for the E ENERGY STAR' Home—Manufactured, Gas& Electric measure is higher
than the expected savings due to the fact that rebate documentation indicated the manufactured home
had electric space and water heating. As such, savings were calculated for this manufactured home
based on the RTF's electric ENERGY STAR' deemed savings value which yielded a 126.44%electric
realization rate for this measure.
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3.2.3 Fuel Conversion Program
Avista's Residential Fuel Conversion 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 have
been at least 4,000 kWh during the prior year with less than 340 therms of natural gas use. Customers
receive incentives after installation and after submitting a completed rebate form. As detailed in the
following table,the Evaluators reference the Avista TRM to calculate the verified savings associated with
this program.
Table 3-10:Fuel Conversion Program Measures
ImpactDescription
Methodology
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 electric energy savings associated with this program. Of note,the
reduction in energy usage is somewhat offset by an increase in gas consumption, as detailed in the
Evaluators' Idaho Gas Portfolio Impact Evaluation Report.
Table 3-11:Fuel Conversion Program Verified Electric Savings
Expected Verified Realization
Measure Project Count Savings Savings Rate
E Electric to Natural Gas Furnace 7 1 51,688.00 J 51,688.00 100.00%
E Electric to Natural Gas Furnace&Water Heat 4 39,156.00 30,717.74 78.45%
Total 11 90,844.00 82,405.74 90.71%
The Fuel Conversion program displayed verified savings of 82,405.74 kWh for a realization rate of
90.71%.The following table summarizes the incentive and measure costs associated with the program.
Table 3-12:Fuel Conversion Program Costs by Measure
Measure Incentive Costs Measure Costs
E Electric to Natural Gas Furnace $14,700.00 $94,182.27
E Electric to Natural Gas Furnace&Water Heat $11,400.00 #$51'903.00
Total $26,100.00146,085.27
The Evaluators describe the impact evaluation tasks completed for this program in the subsections
below.
3.2.3.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Fuel
Conversion Program.The Evaluators sampled a subset of rebates included in the tracking data to cross-
verify key inputs, as summarized in Section 2.2.2.4.
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The Evaluators found that all 11 sampled rebates accurately documented the information necessary to
characterize savings for the program within the Idaho electric service territory.The Evaluators verified
the installed gas equipment and other inputs necessary to calculate verified savings.The Evaluators'
tracking data review did not identify any duplicates in the tracking data.
3.2.3.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Fuel Conversion Program.The Evaluators
referenced the Avista TRM, as detailed above,to calculate verified savings associated with this program.
With a realization rate of 90.71%,verified electric savings matched expected savings relatively closely.
However,the Evaluators found that two of the four water heaters included in the "E Electric to Natural
Gas Furnace &Water Heat" measure did not meet efficiency requirements, which contributed to the
78.45% realization rate for that measure.These two water heaters had a uniform energy factor(UEF) of
0.64 for installed storage water heaters. Outside of this discrepancy all other sampled measures yielded
a 100% realization rate.
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Avista Idaho Electric PY2025 Qualus
3.2.4 Home Energy Audit Program
The Residential Home Energy Audit Program is designed to educate and generate interest in energy
efficiency and to motivate participation in Avista's portfolio of residential energy efficiency and
renewable-energy programs. As a part of this program, participating customers can conduct a DIY home
energy audit using a small thermal camera or a third-party contractor can visit and visually inspect the
customer's entire home to identify opportunities for energy savings. 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 3-13:Home Energy Audit Program Verified Electric Savings
Project Expected Verified Realization
Count Savings Savings Rate
Home Energy Audit 108 NA 86,914.01 NA
Total 108 NA 86,914.01 NA
The Home Energy Audit Program displayed verified savings of 86,914.01 kWh across 108 electric heating
participating households. Avista did not estimate claimed savings for this program, and therefore no
realization rate was calculated. No cost information associated with the Home Energy Audit program
was provided in the tracking data shared with the Evaluators.
The Evaluators summarize the program-specific impact analysis activities, results, conclusions, and
recommendations for the Home Energy Audit Program in the section below.
3.2.4.1 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 Home Energy Audit Program tracking data in PY2025 and
identified participating customers with electric heating in the Idaho service territory.The Evaluators did
not identify any duplicate customers in the ID population tracking data.
3.2.4.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Home Energy Audit Program. The Evaluators
employed the following impact evaluation methodology to estimate verified net energy savings in the
Residential Home Energy Audit Program:
■ Billing Analysis with counterfactual group (IPMVP Option Q
In addition to motivating behavioral changes,the Home Energy Audit program can also provide direct
install measures to participating customers through Avista's residential energy efficiency programs.To
ensure these savings were not double counted,the Evaluators removed all customers participating in
other energy efficiency programs from the Home Energy Audit billing analysis cohort. After removing
these customers with potential for double counted savings from the analysis cohort,the Evaluators
conducted a billing analysis with a counterfactual group selected via propensity score matching.The
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Avista Idaho Electric PY2025 Qualus
methodology used to select the quasi-experimental counterfactual group and the methodology for
linear regression billing analysis are summarized in further detail in Section 2.2.3.3: Billing Analysis.
Table 3-14:Home Energy Audit Program Billing Analysis Results
Treatment Estimated Regression Regression Program
Treatment Customers Annual Saving Estimate p- Estimate Verified Savings
Customers Included in per Customer value Adjusted R- (kWh)
Billing Analysis (kWh) I I squared
108 41 804.76 0.003 0.893 86,914.01
The evaluators ran separate billing analyses for each state and fuel type, meaning the savings results
presented in this report are specific to residential ID participants with electric heating. For the analysis
of the Home Energy Audit program,the Evaluators selected a Post-Program Regression (PPR) model as
detailed in the Model 2: Random Effects Post-Program Regression Model section above. This model
yielded statistically significant average annual savings of 804.76 kWh per household with a p-value of
0.003 and an adjusted R-squared of 0.893, indicating a good model fit to the billing data.This average
savings value corresponds to 4.41%of annual electric consumption of households included in the billing
analysis.This represents substantial electric energy savings and suggests that customers participating in
the Home Energy Audit program in PY2025 have made substantial changes to their electric energy usage
behavior as compared to 2024. The evaluators provide additional information on billing analyses in the
Appendix A: Billing Analysis Results section below.
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3.2.5 Home Insulation Program
Avista's Home Insulation Program (HIP) provides residential customers with a cash incentive to upgrade
the insulation in their homes and thereby save energy. After customers fill out an online form, an Avista
trusted partner will determine household eligibility and then if appropriate conduct a home visit to
check for insulation upgrade opportunities. Should customers agree to the upgrade, the Avista partner
will install the insulation and customers (if they qualify) will receive an incentive upfront. Better
household insulation reduces heat transfer between the outside and inside of a building thereby
reducing heating and cooling energy usage and costs while also improving customer comfort. As a part
of the HIP, Avista offers Attic Insulation, Duct Insulation, Duct Sealing, Floor Insulation, and Wall
Insulation. As detailed in the following table,the Evaluators referenced the RTF's UES Single Family
Weatherization v6.29 and Multifamily Weatherization v6.110 workbooks to determine the verified
savings associated with this program in PY2025.
Table 3-15:Home Insulation Program Measures
ImpactMeasure Description ... .
Attic Insulation Upgrading residential attic insulation RTF UES SF/MF Weatherization
Floor Insulation Upgrading residential floor insulation RTF UES SF/MF Weatherization
Wall Insulation Upgrading residential attic insulation RTF UES SF/MF Weatherization
The following table summarizes the electric energy savings for the HIP impact evaluation.
Table 3-16:Home Insulation Program Verified Electric Savings
Expected Verified Realization
Measure Project Count Savings Savings Rate
Attic Insulation 6 8,942.49 9,051.63 101.22%
Floor Insulation 1 668.53 668.53 100.00%
Wall Insulation 1 1,716.11 1,716.11 100.00%
Total 8 11,327.14 11,436.27 100.96%
The HIP displayed expected savings of 11,327.14 kWh and verified savings of 11,436.27 kWh for a
realization rate of 100.96%.The following table summarizes the incentive and measure costs associated
with the program.
Table 3-17:Home Insulation Program Costs by Measure
Measure Incentive Costs 7`Meas—ur—eCo`s—ts--'
Attic Insulation $6,890.00 $21,295.00
Floor Insulation $712.00 $2,603.78
Wall Insulation $1,152.00 $7,930.00
Total $8,754.00 $31,828.78
The Evaluators describe the impact evaluation tasks completed for this program in the subsections
below.
9 https://rtf.nwcouncil.org/measure/single-family/
io https://rtf.nwcouncil.org/measure/multi-family/
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3.2.5.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Home
Insulation Program.The Evaluators sampled a subset of rebates included in the tracking data to cross-
verify key inputs, as summarized in Section 2.2.2.4.
The Evaluators found that all sampled rebates accurately documented the information necessary to
characterize savings for the program within the Idaho electric service territory.The Evaluators verified
the square footage, insulation thickness (i.e., R-value), heating equipment type, and other inputs
necessary to calculate verified savings based on the RTF UES workbooks described above.The
Evaluators'tracking data review did not identify any duplicates in the HIP tracking data.
3.2.5.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Home Insulation Program.The Evaluators
referenced a set of RTF UES insulation workbooks, as detailed above, to calculate verified savings
associated with this program. With a realization rate of 100.96%,verified electric savings matched
expected savings very closely. However,there were a few key differences in savings methodology. Per
the Evaluators' review, it appeared that Avista also employed RTF UES workbooks to determine savings
associated with this program; however, slight differences in Avista's and the Evaluators application of
the RTF's deemed savings values led to a non-100% realization rate.The three key contributing factors
to differences in RTF savings application appeared to be:
■ Differences in RTF heating zone employed for deemed savings calculations
■ Differences in electric heating equipment used for deemed savings calculations
■ Differences in assigned insulation R-value change applied for deemed savings calculations
To improve concordance between expected and verified savings in the future,the Evaluators would
recommend Avista thoroughly review household heating zone, per customer zip code information, and
electric heating equipment to ensure they are consistently assigning the appropriate RTF deemed
savings value. In addition,while changes in a household's insulation may not perfectly fit into the
insulation buckets provided by the RTF, rounding to the nearest insulation bucket would likely be most
appropriate. For example, for single family attic insulation, the RTF includes RO-R49 and R11-R49
insulation change buckets (among many others). Should a customer's starting insulation be R9 and the
updated insulation be R49,the Evaluators would argue it is most appropriate to assign savings using the
R11-R49 bucket instead of the RO-R49 bucket. Ultimately,the Evaluators concluded that barring a few
minor discrepancies in RTF UES measure savings application,Avista correctly estimated expected savings
for this program.
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3.2.6 Residential Midstream Program
Avista recently 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 residential midstream measures and impact evaluation results are presented in this section.This
change in delivery channel,from downstream to midstream, seems to have expanded the benefits
gained by Avista residential customers.
This section summarizes Avista's estimated savings for the Midstream Program as well as the verified
savings calculated by the Evaluators. Table 3-18 summarizes the measures offered under this program.
Table 3-18:Midstream Program Measures Impact Analysis
Measure Description Methodology
E Heat Pump Water Heater(New New Construction High efficiency heat pump
Construction) water heater installation
E Heat Pump Water Heater(Retrofit) Retrofit High efficiency heat pump water
heater installation
E Mini Split(New Construction) New Construction mini split Air Source Heat Avista TRM midstream
Pump installation measure calculations
E Mini Split(Retrofit) Retrofit mini split Air Source Heat Pump that the Evaluators have
installation reviewed
E Split Unitary Equipment(New New Construction split Air Source Heat Pump
Construction) installation
E Split Unitary Equipment(Retrofit) Retrofit split Air Source Heat Pump
installation
The following table summarizes the estimated electric energy savings for the Midstream Program
impact evaluation.
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Table 3-19:Midstream Program Verified Electric Savings
Expected Verified Realization
Measure Project Count Savings Savings Rate
Heat Pump Water Heater(New Construction) 7 11,285.21 11,285.21 100.00%
Heat Pump Water Heater(Retrofit) 1 1,575.50 1,575.50 100.00%
Mini Split(New Construction) 142 274,093.00 274,052.81 99.99%
Mini Split(Retrofit) 378 928,475.00 926,286.90 99.76%
Split Unitary(New Construction) 137 183,531.00 183,583.96 1 100.03%
Split Unitary(Retrofit) 482 832,503.00 837,692.56 100.62%
Total 1,147 2,231,462.71 2,234,476.95 100.14%
The Midstream Program displayed estimated savings of 2,234,476.95 kWh with a realization rate of
100.14%. The following table summarizes the incentive and measure costs associated with the program,
because complete measure cost information was missing from the tracking data, the Evaluators
assumed incentive and measure costs were identical.
Table 3-20:Midstream Program Incentive Costs by Measure
Measure Incentive Costs Incentive Costs
E Heat Pump Water Heater(New Construction) $1,400.00 $1,400.00
E Heat Pump Water Heater(Retrofit) $650.00 $650.00
E Mini Split(New Construction) $55,850.00 $55,850.00
E Mini Split(Retrofit) $227,300.00 $227,300.00
E Split Unitary Equipment(New Construction) $68,850.00 $68,850.00
E Split Unitary Equipment(Retrofit) $206,200.00 $206,200.00
Total $560,250.00 $560,250.00
The Evaluators describe the impact evaluation tasks completed for this program in the subsections
below.
3.2.6.1 Database Review& Document 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 in
Section 2.2.2.4.
The Evaluators found all selected rebates documented 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 other information necessary to calculate verified savings.
The Midstream tracking data is tracked and delivered separately from the remaining residential
portfolio, often including extensive detail on product characteristics.
3.2.6.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Midstream Program.The Evaluators
reviewed and applied the appropriate Avista TRM values to assign verified savings to each of the
midstream measures. As highlighted in the Impact Evaluation Methodology section above, across 2024
and 2025 the Evaluators have collaborated with Avista to review and verify the methodologies used to
develop the midstream section of Avista's TRM.
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The Evaluators reviewed the implementer expected savings values along with verified tracking data to
estimate net adjusted program savings for those measures. To calculate verified savings,the Evaluators
applied savings values from the Avista TRM that have been reviewed for accuracy by the Evaluators.The
Midstream Program displayed a 100.14% realization rate with 2,234,476.95 kWh saved, as highlighted in
Table 3-19.The Evaluators concluded that the implementers correctly estimated expected savings
values and the deviations in realization rate were primarily due to small differences in the assumed
heating capacity of the equipment being used for savings calculations.
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3.2.7 Residential Shell Program
The Residential Shell Program provides incentives to customers for improving the integrity of their
home's envelope with upgrades to a variety of weatherization measures. Rebates are issued after the
measure has been installed for insulation and window measures. Participating homes must have electric
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. Primary
multifamily homes with shared interior walls including apartments, duplexes, townhomes, and condos
have no minimum usage requirement. Seasonal and recreational homes are not eligible.This program
includes free manufactured home duct sealing. Table 3-21 summarizes the measures offered.
Table 3-21:Shell Program Measures
Impact
MethodologyMeasure Description Analysis
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 homes heated RTF UES
with electricity
E Floor Insulation With Electric Heat Floor insulation for homes heated with electricity RTF UES
E Sliding Glass Doors DIY with Electric High efficiency sliding glass door replacement for homes RTF UES
Heat heated with electricity installed by homeowner
E Sliding Glass Doors with Electric Heat High efficiency sliding glass door replacement for homes RTF UES
heated with electricity installed by contractor
High-efficiency storm window replacement for homes heated
E Storm Window with Electric Heat RTF UES
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 replacement for homes RTF UES
Heating heated with electricity installed by homeowner
E Window Replc from Single Pane W High-efficiency double pane window replacement for homes RTF UES
Electric Heat heated with electricity installed by contractor
E Multifamily Attic Insulation With Attic insulation for homes heated with electricity RTF UES
Electric Heat
E Multifamily Energy Star Certified Replace door with ENERGY STAR rated door in homes heated RTF UES
Insulated Door with electricity
E Multifamily Floor Insulation With Floor insulation for homes heated with electricity RTF UES
Electric Heat
E Multifamily Sliding Glass Doors DIY High efficiency sliding glass door replacement for homes RTF UES
with Electric Heat heated with electricity installed by homeowner
E Multifamily Sliding Glass Doors with High efficiency sliding glass door replacement for homes RTF UES
Electric Heat heated with electricity installed by contractor
E Multifamily Wall Insulation With Wall insulation for homes heated with electricity RTF UES
Electric Heat
E Multifamily Window DIY Replc With High-efficiency double pane window replacement for homes RTF UES
Electric Heating heated with electricity installed by homeowner
E Multifamily Window Replc from High-efficiency double pane window replacement for homes RTF UES
Single Pane W Electric Heat heated with electricity installed by contractor
The following table summarizes the verified electric energy savings for the Shell Program impact
evaluation.
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Table 3-22:Shell Program Verified Electric Savings
Measure Project Count Savings Savings Rate
E Attic Insulation With Electric Heat 12 27,176.46 4,973.17 18.301,
E Energy Star Certified Insulated Door 19 15,037.38 1,318.52 8.77%
E Floor Insulation With Electric Heat 3 2,242.50 1,662.58 74.14%
E Sliding Glass Doors DIY with Electric Heat 2 968.70 546.46 56.41%
E Sliding Glass Doors with Electric Heat 31 12,593.10 12,086.24 95.98%
E Wall Insulation With Electric Heat 5 8,203.34 6,580.79 80.22%
E Window DIY Replc With Electric Heating 17 9,637.10 7,115.15 73.83%
E Window Replc from Single Pane W Electric Heat 111 111,989.00 69,713.25 62.25%
E Multifamily Energy Star Certified Insulated Door 5 4,212.46 357.67 8.49%
E Multifamily Sliding Glass Doors DIY with Electric Heat 2 645.80 364.31 56.41%
E Multifamily Sliding Glass Doors with Electric Heat 8 2,906.10 12,093.59 416.14%
E Multifamily Window DIY Replc With Electric Heating 3 1,089.90 2,213.58 203.10%
E Multifamily Window Replc from Single Pane W 16 10,786.40 30,598.81 283.68%
Electric Heat
Total 234 207,488.24 149,624.12 72.11%
The Shell Program displayed verified savings of 149,624.12 kWh with a realization rate of 72.11%against
the expected savings for the program. The following table summarizes the incentive and measure costs
associated with the program.
Table 3-23:Shell Program Costs by Measure
Measure Row- Incentive Costs Measure Costs
SF E Attic Insulation With Electric Heat $10,958.25 $34,036.56
SF E Energy Star Certified Insulated Door $2,700.00 $66,518.40
SF E Floor Insulation With Electric Heat $2,437.50 $7,694.96
SF E Sliding Glass Doors DIY with Electric Heat $720.00 $7,081.87
SF E Sliding Glass Doors with Electric Heat $18,840.00 $272,546.65
SF E Wall Insulation With Electric Heat $4,332.75 $19,553.98
SF E Window DIY Replc With Electric Heating $7,396.00 $42,400.38
SF E Window Replc from Single Pane W Electric Heat $168,750.00 $1,818,076.00
MF E Energy Star Certified Insulated Door $800.00 $10,945.43
MF E Sliding Glass Doors DIY with Electric Heat $480.00 $1,197.78
MF E Sliding Glass Doors with Electric Heat $3,960.00 $33,174.88
MF E Window DIY Replc With Electric Heating $810.00 $3,764.40
MF E Window Replc from Single Pane W Electric Heat $16,920.00 $133,174.80
Total $239,104.50 $2,450,166.09
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Shell Program in the section below.
3.2.7.1 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 2.2.2.4.
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The Evaluators reviewed each measure's number of units, square footage, and insulation where
available. Not all rebated projects provided sufficient documentation to verify each of the specifications
that the Evaluators reviewed such as square footage quantities for windows and sliding glass doors.
When square footage was not provided,the Evaluators imputed a square footage of 20 square feet per
window and 40 square feet per sliding glass door to apply RTF savings at the square footage level so that
RTF deemed savings could be applied.11,12
The Evaluators found that verified attic insulation, certified insulated doors, and some window measure
savings were lower than expected primarily due to differences in the Avista TRM's application of
deemed savings and the RTF UES workbook application of deemed savings. In most cases Avista applies
a single savings value to each installed measure regardless of customer location or heating equipment
type. In contrast, the RTF differentiates savings by square footage, heating type, R-values (for insulation
measures), U-factors (for window measures), and climate zone.The lack of granularity in the Avista TRM
data led to a low realization rate for many measures.
3.2.7.2 Impact Analysis Savings Verification Findings
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 were finalized.The Evaluators calculated verified savings for each measure using the
active RTF values and verified tracking data.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.
The Shell Program in total displays a realization rate of 76.24%with 790,752.54 kWh verified electric
energy savings in the Idaho service territory, as displayed in Table 3-22.
Realization rates deviate from 100% largely due to two factors. First,there is a significant difference in
the methods applied by the Avista TRM and the RTF for efficient window, insulated door, and sliding
glass door measures.The RTF's deemed savings are estimated at the square-foot unit level, whereas the
Avista TRM estimates savings per window or door.This causes significant variance between the two
estimates when the unit-energy-savings are scaled by two different quantities. It follows that measures
with smaller sample sizes are more vulnerable to this variance, as demonstrated by the low realization
rates in the E Sliding Glass Doors DIY with Electric Heat measure. In addition, in the case of insulated
doors,the Avista TRM assumed doors yielded savings of 800 kWh per door while the RTF assigns savings
between 1.71 and 4.73 kWh per square foot of insulated door. Most sampled doors had relatively small
square footage which yielded substantially lower overall verified savings than Avista's ex-ante estimates.
Second, Attic insulation, wall insulation, and floor insulation measures are evaluated at different
efficiency tiers depending on the R-value of the pre-existing and newly installed insulation. Many of
these projects are displaying lower realization rates due to a mismatch between the ex-ante expected
11 Square footage estimate for residential windows are drawn from a Pacific Northwest National Laboratory analysis found
here: https://www.pnnl.gov/main/publications/external/technical_reports/PNNL-28809.pdf
12 Square footage estimate for residential sliding glass doors are drawn from the RTF's SEEM model found here:
https://nwcounciI.app.box.com/s/oIba73ckvxplogpgO24gclydzz38i3xv
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savings claimed by Avista and the ex-post verified savings calculated based on the RTF. For example,
Avista claimed savings of 1.86 kWh per square foot of attic insulation while the RTF deemed savings
estimate was 0.52 kWh per square foot. In addition to differences in expected and verified savings
insulation savings, several sampled insulation measures did not have R-values that qualified for RTF
savings.Those sampled insulation projects that did not qualify yielded 0 kWh savings which reduced the
sampled realization rate for those measures. Differentiating insulation measure expected savings by
installed R-value and customer location would help Avista's ex-ante estimates align more closely to
verified savings estimates in the future.
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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 serve
households based on a variety of 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.
During PY2025,the Evaluators completed impact evaluations on Avista's Low-Income Program for both
the 2024 and 2025 program years.The following sections summarize findings for each electric impact
evaluation in the Low-Income Portfolio in the Idaho service territory.
The Evaluators used data collected and reported in the tracking database, online application forms,the
Northwest Energy Efficiency Alliance (NEEA) Residential Building Stock Assessment13, and RTF values to
evaluate verified 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 4-1 summarizes the Low Income expected and verified impact savings by
program year.
Table 4-1:PY2025 Low Income Verified Impact Savings by Program Year
Program Year Program Project Count Expected Verified Realization Rate
Savings(kWh) Savings(kWh)
2024 Low Income 64 64,877.67 45,074.37 69.48%
2025 Low Income 124 262202.29 142,111.79 54.20%
Total 188 327:079.96 187,186.16 57.23%
The Idaho Low Income electric program yielded verified savings of 45,074.37 kWh in 2024 and 142.11.79
kWh in 2025 for realization rates of 69.48%and 54.20%, respectively. The following table presents low-
income incentive and measures costs by program year.
Table 4-2:PY2025 Low Income Costs by Program Year
ProgramProgram Year
2024 Low Income $213,699.98 $185,826.05
2025 Low Income $842,001.56 $732,175.24
Total $1,055,701.54 $918,001.29
4.1 Simple Verification Results
Details on the simple verification conducted for the Low Income program are presented below.
13 https:Hneea.org/wp-content/uploads/2025/03/2022-Residential-Building-Stock-Assessment.pdf
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4.1.1 In-Service Rates
4.1.1.1 Low Income Program ISR
The Evaluator conducted a simple participant verification survey for the Low Income Program to
calculate in-services rates of installed measures. Due to the limited number of completed surveys (n =
14), responses from both states were aggregated to increase the stability of the verification estimate.
Based on this combined dataset,the Evaluators calculated an overall installation verification rate of
93%.
Non-verification responses were concentrated among measures such as air sealing and insulation,which
are typically not visible to participants and therefore susceptible to recall error and limited participant
awareness of work performed by contractors. Because all Low Income measures are installed through
program-delivered services rather than customer-directed installations,the likelihood of true non-
installation was assessed to be low. In this context,the observed non-verification is more plausibly
attributed to survey measurement error rather than actual deviations from installation requirements.
Given the small sample size, the nature of the measures involved, and the controlled contractor delivery
model, the evaluation team determined that the most technically appropriate approach was to treat all
Low Income Program measures as fully installed, applying a 100% ISR for the PY2024 and PY2025
evaluation. The survey-derived rate is noted for transparency, but it is not used to downward-adjust
measure savings due to the limitations described above.
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4.2 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.
4.2.1 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.Table 4-3 summarizes the measures offered under this
program.
Table 4-3:Low Income Program Measures
MethodologyMeasure Impact Analysis
E Air Infiltration
E Attic Insulation With Electric Heat
E Conversion to Air Source Heat Pump
E Conversion to Ductless Heat Pump
E Door Sweep
E Duct Insulation
E Duct Sealing
E Exterior Doors RTF UES with NEEA14 weighted heating
E Floor Insulation With Electric Heat adjustments
E Health Safety and Repair
E Heat Pump Water Heater
E Lighting
E Refrigerator
E Smart Thermostat
E Wall Insulation With Electric Heat
E Window Replacement from Single Pane W Electric Heat
Table 4-4 summarizes the PY2024 verified electric energy savings for the Low Income Program impact
evaluation.
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Table 4-4:PY2024 Low Income Program Claimed Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
E Air Infiltration 10 6,310.00 2,306.25 36.55%
E Attic Insulation With Electric Heat 3 2,526.24 7,302.94 289.08%
E Conversion to Air Source Heat Pump 7 41,057.31 21,989.36 53.56%
E Conversion to Ductless Heat Pump 1 3,016.23 1,047.56 34.73%
E Duct Insulation 2 536.00 332.62 62.06%
E Duct Sealing 1 709.93 479.60 67.56%
E Exterior Doors 7 1,619.40 635.25 39.23%
E Floor Insulation With Electric Heat 3 3,547.44 2,176.36 61.35%
E Health Safety and Repair 11 0.00 0.00 N/A
E Lighting 10 62.00 0.00 0.00%
E Refrigerator 1 39.00 58.26 149.39%
E Window Replacement from Single Pane W Electric Heat 8 5,454.12 8,746.18 160.36%
Total 64 64,877.67 45,074.37 69.48%
The Low Income Program in PY2024 displayed verified savings of 45,074.37 kWh with a realization rate
of 69.48%.The following table summarizes the incentive and measure costs associated with the
program in PY2024.
Table 4-5:PY2024 Low Income Program Claimed Costs by Measure
Incentive Cost--- T
E Air Infiltration $20,369.25 $17,712.39
E Attic Insulation With Electric Heat $7,174.10 $6,238.34
E Conversion to Air Source Heat Pump $102,197.49 $88,867.38
E Conversion to Ductless Heat Pump $8,593.26 $7,472.40
E Duct Insulation $937.38 $815.11
E Duct Sealing $264.50 $230.00
E Exterior Doors $9,726.89 $8,458.16
E Floor Insulation With Electric Heat $7,143.97 $6,212.14
E Health Safety and Repair $23,002.59 $20,002.24
E Lighting $279.75 $243.27
E Refrigerator $1,999.85 $1,739.00
E Window Replacement from Single Pane W Electric Heat $32,010.95 $27,835.62
Total $213,699.98 $185,826.05
Total without Health Safety and Repair $190,697.39 $165,823.81
Table 4-6 summarizes the PY2025 verified electric energy savings for the Low Income Program impact
evaluation.
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Table 4-6:PY2025 Low Income Program Claimed Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
E Air Infiltration 15 9,465.00 3,459.37 36.55%
E Attic Insulation With Electric Heat 2 1,217.52 3,519.65 289.08%
E Conversion to Air Source Heat Pump 35 205,286.55 109,946.81 53.56%
E Conversion to Ductless Heat Pump 6 18,097.38 6,285.39 34.73%
E Duct Insulation 5 1,407.00 873.12 62.06%
E Exterior Doors 13 2,591.04 1,016.40 39.23%
E Floor Insulation With Electric Heat 6 7,867.08 4,826.46 61.35%
E Furnace 2 8,654.40 0.00 0.00%
E Health Safety and Repair 24 0.00 0.00 N/A
E Lighting 2 18.00 0.00 0.00%
E Window Replacement from Single Pane W Electric Heat 14 7,598.32 12,184.60 160.36%
Total 124 262,202.29 142,111.79 54.20%
The Low Income Program in PY2025 displayed verified savings of 142,111.79 kWh with a realization rate
of 54.20%.The following table summarizes the incentive and measure costs associated with the
program in PY2025.
Table 4-7:PY2025 Low Income Program Claimed Costs by Measure
Measure Incentive Costs Measure Costs
E Air Infiltration $20,877.32 $18,154.18
E Attic Insulation With Electric Heat $2,426.21 $2,109.75
E Conversion to Air Source Heat Pump $526,074.19 $457,455.82
E Conversion to Ductless Heat Pump $94,210.30 $81,922.00
E Duct Insulation $3,397.24 $2,954.12
E Exterior Doors $17,061.81 $14,836.34
E Floor Insulation With Electric Heat $13,141.52 $11,427.41
E Furnace $15,743.04 $13,689.60
E Health Safety and Repair $80,516.52 $70,014.35
E Lighting $78.24 $68.04
E Window Replacement from Single Pane W Electric Heat $68,475.17 $59,543.63
Total $842,001.56 $732,175.24
Total without Health Safety and Repair $761,485.04 $662,160.89
4.2.1.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators performed a comprehensive review of the Low
Income Program tracking database to assess data completeness, accuracy, and consistency. As part of
this process,the Evaluators selected a random subset of rebate applications to cross-verify tracking
system inputs with submitted project documentation, as summarized in Section 2.2.2.4.The Evaluators
found no duplicate participants in the project data and found that program data appropriately reflected
customer rate information.
4.2.1.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Low Income Program for PY2024 and
PY2025.The Evaluators calculated verified savings for the electric measures using the RTF workbook in
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place at the time the savings goals for the program were finalized.These RTF 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.
The Low Income Program displayed the following savings and realization rates for each project year:
■ PY2024: 45,074.37 kWh, 69.48% RR
■ PY2025: 142,111.79 kWh, 54.20% RR
Measure details can be found in Table 4-5 and Table 4-7. Potential causes of discrepancies between
reported and verified savings for the Low Income Program are outlined in the sections below.
Heating Type Data Gaps
The tracking data did not indicate the type of electric heating established in each participating
household. Because heating system type is a required input for Regional Technical Forum (RTF) savings
calculations,the Evaluators applied weighted heating type averages derived from the 2022 Northwest
Energy Efficiency Alliance (NEEA) Residential Building Stock Assessment.
Measure Quantity Field Inconsistencies
The measure quantity field in the tracking data was populated inconsistently across measure types. For
example, for insulation measures,the quantity represented square footage installed,whereas for other
measures, such as door sweeps or ASHPs,the field represented count of units or projects installed.
To support future evaluations and ensure data clarity,the Evaluators recommend that the tracking
system include separate, measure-specific data fields (e.g., "Installed Area (sq ft)," "Quantity Installed,"
"Units per Project")to reduce ambiguity and improve data usability.
Manufactured and Multifamily Home Treatment
In cases where RTF savings methodologies do not provide measure-specific savings values for
Manufactured or Multifamily homes,the Evaluators applied Single Family savings values.
Air Source Heat Pump (ASHP) Data Limitations
RTF savings methodologies for air source heat pumps require information on whether the home's
pre-existing heating system included central air conditioning.This detail was not captured in the
program's tracking system.To address this gap, the Evaluators used publicly available resources to
determine whether individual homes had central AC.This information incorporated into each project's
impact analysis to more accurately categorize pre-existing system types and apply RTF savings values.
Exterior Door Assumptions
The tracking database did not include the square footage of replacement exterior doors. To complete
the savings calculations,the Evaluators assumed an average replacement door area of 20 square feet
per project, based on typical residential door dimensions.
Window Measure Data Gaps
RTF savings methodologies for windows require identification of installed window type. Because the
tracking data only listed the pre-existing window type, the Evaluators applied a conservative assumption
framework when assigning savings.
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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 PY2025.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-approved analyses, and supplemental sources 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
Program Project Count Expected Savings Verified Savings Realization
Building Operator Certification 1 0.00 119,000.00 NA
Green Motors 2 10,529.00 7,625.21 72.42%
Grocer 1 2,919.00 2,918.58 99.99%
Non Residential Midstream 69 163,821.00 163,691.23 99.92%
Prescriptive Lighting 471 3,818,500.45 3,900,750.23 102.15%
Small Business Lighting 1,924 18,592,355.85 18,962,968.96 101.99%
Non Residential Shell 2 14,280.42 10,120.54 70.87%
Site Specific-Lighting 6 101,225.00 91,700.23 90.59%
Site Specific-Other 9 9,746,501.06 9,419,907.14 96.65%
Total 21485 32,450,131.78 32,678,682.11 100.70%
Non Residential program incentive and measure costs are presented in the following table. Measure
costs were not presented in the Non Residential midstream program tracking data and as such they
were assumed to be identical to incentive costs.
Table 5-2:Non Residential Costs by Program
r Program Incentive Costs Measure Costs
Building Operator Certification $0.00 $0.00
Grocer $1,400.00 $31,285.00
Non Residential Midstream $300.00 $945.00
Prescriptive Lighting $74,140.00 $74,140.00
Small Business Lighting $835,378.12 $1,712,561.61
Non Residential Shell $10,726,871.91 $11,176,233.52
Site Specific-Lighting $13,883.38 $29,800.00
Site Specific-Other $19,639.61 $72,226.27
Total $13,623,869.24 $18,069,032.25
In PY2025, verified energy savings of 32,678,682.11 kWh were identified for Avista's non-residential
electric measures in Idaho.All programs except for the Green Motors and Non Residential Shell program
had realization rates between 90% and 103%.The Green Motors program had a realization rate of
72.42%while the Non Residential Shell program had a 70.87% realization rate.The Building Operator
Certification program did not yield a realization rate due to no expected savings being claimed;
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however,the Evaluators identified 119,000.00 kWh verified savings associated with the program. Across
all Non Residential programs the Evaluators calculated a 100.70% realization rate.
5.1 Database & Document Verification
Before conducting the impact analyses,the Evaluators conducted a database review for all prescriptive
programs.This process began with the selection of representative samples from each program. The
Evaluators developed a sampling plan that achieves a sampling precision of±10% at 90%statistical
confidence—or"90/10 precision"—for document verification. Details about sampling methods can be
found in 2.2.1 Database Review and details about the verification process can be found in Section
2.2.2.4.The Evaluators reviewed both tracking data and additional documentation materials to identify
any typos, duplicates, or other data concerns that might affect the verified savings analysis. Information
on the sample sizes reviewed as a part of the database and document verification process can be found
in the Sampling Methodology for Most Programs section above.
5.2 Survey Verification
Unlike residential measures, non-residential measures typically have a 100% installation rate or a
deemed in-service rate (ISR) included in RTF and/or Avista TRM. One key exception to this is the
Prescriptive Lighting program, as lighting equipment if often small and inexpensive enough that
customers can forget to install measures.To address this,the Evaluators conducted survey verification
to identify an in-service rate for the Prescriptive Lighting program.
5.2.1 Prescriptive Lighting In-Service Rates
The Evaluators calculated in-service rates (ISRs) of installed measures from simple verification surveys
deployed to program participants in the Prescriptive Lighting program.The Evaluators asked participants
if the rebated equipment is currently installed and working. Measure-specific in-service rates for the
Idaho service territory can be found in the following table.The Evaluators assumed an in-service rate of
100%for any measures not included in the following table.
Table 5-3:Prescriptive Lighting In-Service Rates
.. ISR Methodology
Prescriptive All Lighting Measures 57 98.25% Verification survey
Lighting
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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.
5.3.1 Building Operator Certification
The C&I Building Operator Certification (BOC) Program is being offered by Avista in the 2025-2026
biannual period. This program is offered to encourage building operator certified credentialed operators
to save energy 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 impactsls
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 5-4 summarizes the electric measures offered under this program and corresponding impact M&V
methodology source, for each building operator certification completed in PY2025.
Table 5-4:Building Operator Certification Program UES Sources
Measure Impact Analysis Savings Section(s)
Building Operator Certification—Electric
W
Building Operator Certification—Natural Gas UTC approved BOC's energy savings impactsl6
The independent study by Navigant17 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 5-5:BOC Program Verified Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
Building Operator Certification 1 NA 119,000.00 NA
Total 1 NA 119,000.00 NA
Incentive and measure costs were not included in the BOC tracking data and as such the following table
presents "NA"values for both.
15 https://www.theboc.info/wp-content/uploads/2020/08/2020-BOC-Energy-Savings-FAQ_1.O.pdf
16 https://www.theboc.info/wp-content/uploads/2020/08/2020-BOC-Energy-Savings-FAQ_1.O.pdf
17https://www.theboc.info/pdf/Eval-Ell-223_LTMT.pdf
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Table 5-6: BOC Program Costs by Measure
Project Count Incentive Costs Measure Costs
Building Operator Certification 1 NA NA
Total 1 NA NA
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the BOC Program in the section below.
5.3.1.1 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 1 building operator certification was completed in 2025.
5.3.1.2 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 are 119,000.00 kWh as displayed in Table 5-5.
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5.3.2 Green Motors Program
The Green Motors Program ensures quality rewinding that results in a 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, which 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.The Green Motors Program provides up to a $10,000 incentive for a 5,000 HP motor.
Table 5-10 summarizes the measures rebated in PY2025 under this program.
Table 5-7: Green Motors Program Measures
MethodologyMeasure i Impact Analysis
Motor Rewind (Industrial) I RTF UES Green Motor Rewind Measure v5.2
The following table summarizes the verified electric energy savings for the Green Motors Program
impact evaluation.
Table 5-8: Green Motors Program Verified Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
Motor Rewind (Industrial) 2 10,529.00 7,625.21 72.42%
Total 2 10,529.00 7,625.21 72.42%
The following table summarizes the incentive and measure costs associated with the program.
Table 5-9:Green Motors Program Costs by Measure
Measure Measure Unit Incentive Costs Measure Costs
Count I A
Motor Rewind (Industrial) 2 $1,400.00 $31,285.00
Total 2 $1,400.00 $31,285.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Green Motors Program in the section below.
5.3.2.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Green
Motors Program.The Evaluators review all rebate applications to cross-verify tracking data inputs. Data
points checked between project applications and program tracking data including measure specification,
quantity, and cost values.The Evaluators did not identify any duplicates or errors in the tracking data or
other program documentation.
5.3.2.2 Impact Analysis
This section summarizes the verified savings results for the Green Motors Program.The Evaluators
calculated verified savings for the two installed measures using the appropriate RTF UES workbook. Per
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the RTF UES Green Motor Rewind workbook,the Evaluators applied different savings to the two
rewound motors based on their horsepower.
5.3.2.3 Verified Savings
The Evaluators reviewed and applied the appropriate UES values to the verified tracking data to
estimate program savings for the two projects.The verified savings for the program are 7,625.21 kWh
with a realization rate of 72.42%.The variance between expected and verified savings seems to be due
to different assumptions regarding the efficiency improvements associated with motor rewinds
between the Avista TRM and the RTF UES workbook.Avista's expected savings were 4,535.00 kWh and
5,994.00 kWh for a 300 and a 400 HP motor, respectively. In contrast,the RTF suggests savings of
3,284.11 kWh for the former and 4,341.10 for the latter.
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5.3.3 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 5-10 summarizes the measures rebated in PY2025 under this program.
Table 5-10:Grocer Program Measures
Measure Impact Analysis Methodology
Walk-In Evaporator Fan Motor Retrofit RTF Commercial Grocery Walk-In
Evaporator Fan Motor Retrofit v.5.1
The following table summarizes the verified electric energy savings for the Grocer Program impact
evaluation.
Table 5-11:Grocer Program Verified Electric Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
Walk-In Evaporator Fan Motor 1 2,919.00 2,918.58 99.99%
Retrofit
Total 1 2,919.00 2,918.58 99.99%
The following table summarizes the incentive and measure costs associated with the program.
Table 5-12:Grocer Program Costs by Measure
Measure Measure Unit Incentive Costs Measure Costs
Walk-In Evaporator Fan
Motor Retrofit 3 $300.00 $945.00
Total 3 $300.00 $945.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Grocer 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 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 data including
measure specification, quantity and cost values.
Table 5-13 shows the project population, the number of projects checked and the overall precision.
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Table 5-13: Grocer Verification Precision
Population Precision
1 1 0.0%
The Evaluators found all rebate equipment met or exceeded the measure efficiency requirements for
the Grocer Program.
5.3.3.2 Impact Analysis
This section summarizes the verified savings results for the Grocer Program.The Evaluators calculated
verified savings for the food service measures using the appropriate RTF UES to a census of measures.
5.3.3.3 Verified Savings
The Evaluators reviewed and applied the appropriate UES values to the verified tracking data to
estimate program savings for the included measures.The verified savings for the program are 2,918.58
kWh with a realization rate of 99.99%, as displayed in Table 5-12.The variance between reported and
verified savings is attributable to the reported savings calculations rounding UES values to the nearest
integer, whereas the verified savings calculations utilized the precise UES values.
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5.3.4 Non Residential 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, 2024,
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 non-residential
customers.This chapter discusses and presents results only for non-residential measures.Table 5-14
summarizes the measures available to be rebated in PY2025 under this program.
Table 5-14:Non Residential Midstream Program Measures
MethodologyEnd Use Measure Impact Analysis
Combination Oven Avista TRM (per RTF Combination Ovens)
Convection Oven Avista TRM (per RTF Convection Ovens)
Demand Control Kitchen Ventilation Avista TRM
Dishwasher Avista TRM (per ENERGY STAR CFS Calculator)
Fryer Avista TRM
Food Service Griddle Avista TRM (per RTF Griddles)
Hot Food Holding Bin Avista TRM (per CA eTRM HFHB)
Hot Food Holding Cabinet RTF HFHC
Ice Machine Avista TRM (per RTF Ice Machines)
Rotisserie Oven Avista TRM (per CA eTRM Rotisserie Ovens)
Steamer Avista TRM (per RTF Steamers)
Boiler Avista TRM (per RTF Commercial Boilers)
Furnace Avista TRM (per billing analysis)
HVAC Mini/Multi Split Avista TRM (per engineering algorithm)
Packaged Unitary Equipment Avista TRM (per engineering algorithm)
Split Unitary Equipment Avista TRM (per engineering algorithm)
Water Source Heat Pump Avista TRM (per engineering algorithm)
Heat Pump Water Heater Avista TRM (per RTF HPWH)
Water Heating Instantaneous Water Heater Avista TRM (per RTF Gas Water Heaters)
Storage Water Heater Avista TRM (per RTF Gas Water Heaters)
Other Ultra-Low Temperature Freezer Avista TRM (per CA eTRM Ultra Low Temp
Freezers)
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The following table summarizes the verified electric energy savings for the Midstream Program impact
evaluation.
Table 5-15: Non Residential Midstream Program Verified Electric Savings
9-4 Project r__Expected Savings' Verified Savings I
Measure Count (kWh) (kWh) Realization Rate
Combination Oven 1 3,868.00 3,868.00 100.00%
Dishwasher 3 24,917.00 24,917.00 100.00%
Hot Food Holding Bin 2 8,802.00 8,802.00 100.00%
Ice Machine 3 953.00 953.00 100.00%
Mini/Multi Split 48 84,549.00 84,422.71 99.85%
Split Unitary Equipment 9 14,366.00 14,361.30 99.97%
Ultra-Low Temperature Freezer 3 26,366.00 26,367.21 100.00%
Total 69 163,821.00 163,691.23 99.92%
The following table summarizes the incentive and measure costs associated with the program. Of note,
no complete cost information outside of incentive costs was included in the tracking data provided, and
as such the Evaluators have assumed incentive costs are identical to overall measure costs.
Table 5-16:Non Residential Midstream Program Costs by Measure
r Measure Measure Unit Incentive Costs Measure Costs
Count
Combination Oven 1.00 $850.00 $850.00
Dishwasher 3.00 $3,220.00 $3,220.00
Hot Food Holding Bin 3.00 $1,695.00 $1,695.00
Ice Machine 4.00 $575.00 $575.00
Mini/Multi Split 50.00 $54,900.00 $54,900.00
Split Unitary Equipment 9.00 $5,100.00 $5,100.00
Ultra-Low Temperature Freezer 6.00 $7,800.00 $7,800.00
Total 76.00 $74,140.00 $74,140.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Midstream Program in the section below.
5.3.4.1 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. 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. Furthermore, no
duplicates were identified in the tracking data.
5.3.4.2 Impact Analysis
Once verification was completed, to estimate program savings for these measures the Evaluators
reviewed and applied the appropriate Avista TRM values to assign verified savings to each of the
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midstream measures. As highlighted in the Impact Evaluation Methodology section above, across 2024
and 2025 the Evaluators have collaborated with Avista to review and verify the methodologies used to
develop the midstream section of Avista's TRM. For measures not included in the TRM,the Evaluators
referenced a relevant RTF workbook to identify appropriate verified savings values. Savings values are
specific to installed equipment efficiency and configuration.
5.3.4.3 Verified Savings
The verified savings for the program are 163,691.23 kWh with a realization rate of 99.92%.All measures
except had realization rates within a percentage of 100%, suggesting excellence consistency in ex-ante
and ex-post savings methodologies. Slight differences in savings calculation parameters one sampled
Mini/Multi Split project and a difference in rounding for two sampled Split Unitary Equipment measures
contributed to their non-100% realization rates.
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5.3.5 Prescriptive Lighting Program
This 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 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 a pre-
determined incentive for many common lighting retrofits,thereby streamlining the energy efficiency
and rebate delivery process. The Prescriptive Lighting program makes it easier for customers—especially
smaller customers and vendors—to improve the efficiency of their lighting equipment.
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.Table 5-17 summarizes the measures offered under this program.
Table 5-17: Prescriptive Lighting Program Measures
MethodologyImpact Analysis
LED tubes
LED U-Bend
LED W reduction
LED Down lamps/Directional
Interior Linear LED Fixtures Prescriptive Calculations with RTF
HID LED fixtures/lamps and Custom Inputs
Occupancy Sensors
LLLC Fixtures
Exterior
HID LED fixtures/lamps
Sign Lighting
Prescriptive Lighting Program impact evaluation results by measure type are summarized in Table 5-18.
Table 5-18:Prescriptive Lighting Program Verified Electric Savings
Measure Type Project Expected Verified Realization
Count Savings(kWh) Savings(kWh) Rate
TLED(4') Lamp to TLED(4') Lamp with 5 watt 4 108,074.59 112,560.11 104.15%
or more reduction
T12/T8(4') Lamp to 1-Lamp less than 23
88 868,677.28 879,206.78 101.21%
watt T8 TLED
DLC Qualified LLLC Fixture 31 52,120.50 53,013.65 101.71%
T12/T8 U-Bend to less than 23 watt T8 LED 3 49,109.58 49,212.97 100.21%
T12/T8(2') Lamp to 1-Lamp less than 13 5 4,136.60 4,128.58 99.81%
watt T8 TLED
2-Lamp T12/T8 Fixture to LED Qualified 1x4 12 7,859.07 8,081.34 102.83%
Fixture
Wall Switch Occupancy Sensor 7 2,138.44 2,138.28 99.99%
T12/T8(3') Lamp to 1-Lamp less than 17 2 657.28 656.01 99.81%
watt T8 TLED
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2,3,4-Lamp T12/T8 Fixture to LED Qualified 47 387,475.83 394,028.49 101.69%
2x4 Fixture
*>=42W CFL to<=20W LED Fixture* 9 28,857.31 29,651.12 102.75%
Four Pin Base CFL to 17 watt or less Plug in 11 29,759.54 33,809.09 113.61%
LED
T12/T8 8' Fixture to 90 watt or less 8' LED 24 83,296.86 81,427.55 97.76%
fixture _
2-Lamp T12/T8 Fixture to LED Qualified 2x2 6 11,283.78 10,951.89 97.06%
Fixture
Ceiling or Fixture Occupancy sensor with 12 32,619.16 31,659.13 97.06%
built-in relays
Sign Lighting 38 136,246.76 140,240.43 102.93%
65W Incandescent to<=10 watt LED Fixture 2 18,798.78 21,961.89 116.83%
75-100 watt Incandescent Can to less than 9 202,377.86 244,020.83 120.58%
20 watt LED Fixture Retrofit
400 watt HID Fixture to 175 watt or less LED 12 194,290.62 196,335.35 101.05%
Fixture
70-89 watt HID Fixture to 25 watt or less LED 4 8,326.16 8,365.67 100.47%
Fixture or Retrofit(Ext)
T12/T8 Eight-Foot to LED 18 83,451.16 80,995.06 97.06%
T5HO Lamp to 1-Lamp less than 29 watt 10 120,943.16 122,646.48 101.41%
T5HO TLED
90-100 watt HID Fixture to 30 watt or less
L 5 14,261.61 14,329.28 100.47%
LED Fixture or Retrofit(Ext)
*>=150W Incandescent to<=30W LED 9 435,210.36 447,182.10 102.75%
Fixture*
175 watt HID Fixture to 100 watt or less LED 21 92,895.05 91,692.61 98.71%
Fixture or Retrofit(Ext)
175 watt HID Fixture to 100 watt or less LED 2 3,103.72 3,163.89 101.94%
Fixture(Ext, NC)
250-watt HID Fixture to 140-watt or less LED 4 30,493.63 26,151.87 85.76%
Fixture
150 watt HID Fixture to 50 watt or less LED 7 43,739.65 45,086.51 103.08%
Fixture or Retrofit(Ext)
T5HO(4')4-Lamp to 135 watt of less LED 2 11,736.40 10,111.76 86.16%
Fixture
250 watt HID Fixture to 140 watt or less LED 1 716.46 730.35 101.94%
Fixture(Ext, NC)
250 watt HID Fixture to 140 watt or less LED 6 43,012.56 42,901.49 99.74%
Fixture or Retrofit(Ext)
175-watt HID Fixture to 75-watt or less LED 1 1,188.72 1,170.60 98.48%
Fixture
200 watt HID Fixture to 140 watt or less LED 1 1,271.56 1,277.59 100.47%
Fixture or Retrofit(Ext)
400 watt HID Fixture to 175 watt or less LED
42 510,495.31 513,492.79 100.59%
Fixture or Retrofit(Ext)
T5HO(4')6-Lamp to 165 watt of less LED 11 68,840.81 66,457.28 96.54%
Fixture
320 watt HID Fixture to 160 watt or less LED 1 1,755.47 1,763.80 100.47%
Fixture or Retrofit(Ext)
Sign Lighting Container 2 8,648.64 8,816.30 101.94%
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1000 watt HID Fixture to 400 watt or less
LED Fixture or Retrofit(Ext) 2 120,630.18 121,331.29 100.58%
Total 471 3,818,500.45 3,900,750.23 102.15%
The following table summarizes the incentive and measure costs associated with the program.
Table 5-19:Prescriptive Lighting Program Costs by Measure
Measure Type Measure Unit Incentive Measure
Count Costs Costs
TLED(4') Lamp to TLED(4') Lamp with 5 watt or 4,384.00 $21,920.00 $74,970.07
more reduction
T12/T8(4') Lamp to 1-Lamp less than 23 watt T8 14,892.00 $183,483.52 $328,234.54
TLED
DLC Qualified LLLC Fixture 932.00 $48,600.00 $66,198.17
T12/T8 U-Bend to less than 23 watt T8 LED 1,018.00 $15,270.00 $15,583.97
T12/T8(2') Lamp to 1-Lamp less than 13 watt T8 169.00 $1,014.00 $5,646.00
TLED
2-Lamp T12/T8 Fixture to LED Qualified 1x4 87.00 $2,610.00 $12,744.77
Fixture
Wall Switch Occupancy Sensor 13.00 $130.00 $2,645.78
T12/T8(3') Lamp to 1-Lamp less than 17 watt T8 12.00 $120.00 $357.16
TLED
2,3,4-Lamp T12/T8 Fixture to LED Qualified 2x4 1,558.00 $77,900.00 $160,928.43
Fixture
*>=42W CFL to<=20W LED Fixture* 278.00 $5,560.00 $22,980.21
Four Pin Base CFL to 17 watt or less Plug in LED 332.00 $5,248.34 $9,776.98
T12/T8 8' Fixture to 90 watt or less 8' LED fixture 371.00 $26,370.00 $60,489.04
2-Lamp T12/T8 Fixture to LED Qualified 2x2 73.00 $1,825.00 $43,864.68
Fixture
Ceiling or Fixture Occupancy sensor with built-in
211.00 $6,330.00 $24,489.64
relays
Sign Lighting 2,768.00 $35,986.86 $86,597.30
65W Incandescent to<=10 watt LED Fixture 40.00 $1,200.00 $5,388.98
75-100 watt Incandescent Canto less than 20 497.00 $19,880.00 $38,200.74
watt LED Fixture Retrofit _
400 watt HID Fixture to 175 watt or less LED
156.00 $47,207.40 $58,101.71
Fixture _
70-89 watt HID Fixture to 25 watt or less LED
25.00 $1,982.98 $3,521.62
Fixture or Retrofit(Ext)
T12/T8 Eight-Foot to LED 836.00 $20,870.69 $65,347.27
T5HO Lamp to 1-Lamp less than 29 watt T5HO 1,327.00 $40,310.00 $77,172.60
TLED
90-100 watt HID Fixture to 30 watt or less LED 31.00 $3,630.13 $5,644.69
Fixture or Retrofit(Ext)
*>=150W Incandescent to<=30W LED Fixture* 450.00 $33,750.00 $58,565.29
175 watt HID Fixture to 100 watt or less LED 143.00 $25,061.36 $41,143.38
Fixture or Retrofit(Ext)
175 watt HID Fixture to 100 watt or less LED 5.00 $850.00 $3,210.00
Fixture(Ext, NC)
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250-watt HID Fixture to 140-watt or less LED
36.00 $9,140.33 $11,691.09
Fixture
150 watt HID Fixture to 50 watt or less LED 63.00 $11,340.00 $22,607.43
Fixture or Retrofit(Ext)
T5HO(4')4-Lamp to 135 watt of less LED Fixture 27.00 $2,970.00 $3,730.65
250 watt HID Fixture to 140 watt or less LED 1.00 $225.00 $450.00
Fixture(Ext, NC)
250 watt HID Fixture to 140 watt or less LED 51.00 $11,131.85 $24,962.60
Fixture or Retrofit(Ext)
175-watt HID Fixture to 75-watt or less LED 3.00 $420.00 $1,066.60
Fixture
200 watt HID Fixture to 140 watt or less LED
Fixture or Retrofit(Ext) 2.00 $240.00 $543.85
400 watt HID Fixture to 175 watt or less LED 369.00 $137,030.60 $309,958.65
Fixture or Retrofit(Ext)
T51HO(4')6-Lamp to 165 watt of less LED Fixture 167.00 $23,204.00 $46,345.38
320 watt HID Fixture to 160 watt or less LED
2.00 $560.00 $2,284.94
Fixture or Retrofit(Ext)
Sign Lighting Container 176.00 $2,288.00 $7,399.34
1000 watt HID Fixture to 400 watt or less LED 28.00 $9,718.06 $9,718.06
Fixture or Retrofit(Ext)
Total 31,533.00 $835,378.12 $1,712,561.61
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.
5.3.5.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Prescriptive
Lighting Program. The evaluated reviewed sampled lighting measures for tracking data accuracy and
also conducted research to ensure facility type was correctly assigned to each customer included in the
sample. Facility type has an impact heating/cooling interactive factors as well as on lighting control
savings, meaning accurate facility type assignment is essential for verified savings calculations. No major
data issues were identified in the tracking data and facility type review of sampled projects.
5.3.5.2 Impact Analysis
The Evaluators calculated verified savings by using a standard engineering algorithm:
kWh ([Nfixt(i) xWfixt(i) — N x Wfixt(i) x AOH x ISR
savings — 1000 ]pre fixt(i) 1000 1post
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 (varies). Self-reported.
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, 98.25% per the Evaluators' process analysis.
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The kWh lighting savings calculated using the above equation were adjusted to take into account
lighting controls, cooling interactive factors, and heating interactive factors, as necessary. Lighting
control savings as well as heating/cooling interactive factors are calculated as a percentage of the kWh
savings presented above, so where appropriate the Evaluators added those adjustments to determine
final verified lighting savings values. Lighting control percentage adjustments as well as heating/cooling
interactive factors vary based on fuel type, lighting installation location, and facility type. Fuel type and
whether or not lighting controls were installed were included in tracking data.The specific percentage
adjustments used in savings calculations were sourced from the RTF Non Residential Lighting calculator
workbook.
5.3.5.3 Verified Savings
The verified savings for the program are 3,900,750.23 kWh with a realization rate of 102.15%.The
Evaluators used the RTF Non Residential Lighting18 calculator and protocol to calculate savings and
assigned a survey-based in-service rate to those savings values.This methodology resulted in slightly
higher verified savings than expected. This difference in expected and verified savings is primarily due to
differences in assign facility type which contributes to calculated lighting savings.While expected
savings calculations did not seem to take into account an in-service rate,the in-service rate was 98.25%
meaning the impact on overall savings was minimal. Broadly, expected and verified savings matched
closely for this program.
18 https://rtf.nwcouncil.org/standard-protocol/non-residential-lighting-retrofits/
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5.3.6 Small Business Lighting Program
The Small Business Lighting Program is a non-residential direct install lighting program that offers
lighting and controls assessments, equipment and installation for commercial customers on rate
schedules 11 or 12.To participate, businesses fill out an application on Avista's website and then are
contacted by a program partner. An on-site assessment is scheduled to identify potential lighting and
sensor upgrades and eligibility is verified. Measures are then installed at low/no cost to the participant
and incentivized at $0.40 -$0.65/kWh. Table 5-20 summarizes the measures offered.
Table 5-20:Small Business Lighting Program Measures
MethodologyMeasure Impact Analysis
LED Fixture-replacing FLT12,400W-1000W w&w/o OS
LED Fixture-replacing FLT5:2ft to 8ft, 14W-54W w&w/o OS
LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W w&w/o OS
LED Fixture-replacing Halogen/Incandescent lamp, 150W-1500W w&w/o OS
LED Fixture-replacing Halogen/Incandescent lamp,20-150W w&w/o OS
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,<100W
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp, 100W-250W w&w/o OS
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,320W-400W w&w/o OS
LED Fixture-replacing Metal Halide/High Pressure Sodium lamp,400W-1000W w&w/o OS
LED Fixture-replacing T12:2ft-8ft,34W-80W w&w/o OS
LED Replacement Lamp-replacing CFL Screw-in/Pin-based,8W-40W
LED Replacement Lamp-replacing FLT12:2ft to 8ft,34W-80W w&w/o OS
LED Replacement Lamp-replacing FLT5:2ft to 8ft, 17W-54W w&w/o OS
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W-59W w&w/o OS
LED Replacement Lamp-replacing Halogen/Incandescent lamp, 150-1500W Prescriptive
LED Replacement Lamp-replacing Halogen/Incandescent lamp,20-150W w&w/o OS Calculations with
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium lamp,<100W RTF and Custom
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium lamp, 100W-250W Inputs
LED Replacement Lamp-replacing Metal Halide/High Pressure Sodium lamp,320W-400W
ALED Replacement Lamp-replacing Metal Halide/High Pressure Sodium lamp,400W-1000W
LED Retrofit Kit-replacing CFL,8W-40W
LED Retrofit Kit-replacing FLT12,400W-1000W w&w/o OS
LED Retrofit Kit-replacing FLT12:2ft to 8ft,34W-80W w&w/o OS
LED Retrofit Kit-replacing FLT5:2ft to 8ft, 14W-54W w&w/o OS
LED Retrofit Kit-replacing FLT8:2ft to 8ft, 17W-59W w&w/o OS
LED Retrofit Kit-replacing Halogen/Incandescent lamp,20-150W
LED Retrofit Kit—replacing Halogen/Incandescent lamp,20-15OW w&w/o OS
LED Retrofit Kit-replacing Halogen/Incandescent lamp,20-150W with OCC w&w/o OS
LED Retrofit Kit-replacing Metal Halide/High Pressure Sodium lamp,<100W
LED Retrofit Kit-replacing Metal Halide/High Pressure Sodium lamp, 100W-250W
LED Retrofit Kit-replacing Metal Halide/High Pressure Sodium lamp,320W-40OW
LED Retrofit Kit-replacing Metal Halide/High Pressure Sodium lamp,400W- 1000W
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Small Business Lighting Program impact evaluation results by measure are summarized in Table 5-21.
Table 5-21:Small Business Lighting Program Verified Electric Savings
Measure Type Project Expected IF Verified Realization
9r Count Savings(kWh) Savings(kWh) Rate
LED Fixture-replacing Metal Halide/High 150 631,033.03 610,686.05 96.78%
Pressure Sodium lamp, 100W-250W
LED Replacement Lamp-replacing FLT8: 2ft to
95 507,476.14 482,518.62 95.08%
8ft, 17W-59W
LED Fixture-replacing Halogen/Incandescent
340 1,422,437.15 1,473,820.55 103.61%
lamp,20-150W
LED Fixture-replacing FLT8:2ft to 8ft, 17W- 327 3,910,184.20 3,858,998.64 98.69%
59W
LED Fixture-replacing CFL Screw-in/Pin-based, 16 120,675.14 112,582.83 93.29%
8W-40W
LED Retrofit Kit-replacing FLT8:2ft to 8ft, 17W- 31 430,997.80 465,213.84 107.94%
59W
LED Replacement Lamp-replacing FLT12:2ft to 0
8ft,34W-80W 53 238,856.10 220,332.08 92.24/
LED Retrofit Kit-replacing CFL,8W-40W 5 31,879.00 37,298.42 117.00%
LED Fixture-replacing FLT5:2ft to 8ft, 14W- 65 885,892.12 908,569.39 102.56%
54W
LED Retrofit Kit-replacing Halogen/Incandescent 134 671,040.63 740,582.97 110.36%
lamp,20-150W
LED Fixture-replacing FLT8:2ft to 8ft, 17W- 24 596,421.75 636,102.61 106.65/
59W with OCC
LED Fixture-replacing T12: 2ft-8ft,34W-80W 299 2,652,104.59 2,442,921.40 92.11%
LED Fixture-replacing Metal Halide/High
Pressure Sodium lamp,<100W 9 23,348.84 24,218.18 103.72/0
LED Fixture-replacing Halogen/Incandescent
9 16,733.27 20,691.87 123.66%
lamp,20-150W with OCC
LED Replacement Lamp-replacing FLT5: 2ft to 0
8ft, 17W-54W 16 122,683.77 106,734.88 87.00%
LED Replacement Lamp-replacing FLT8:2ft to 0
8ft, 17W-59W with OCC 2 375.14 362.47 96.62/LED Fixture-replacing Halogen/Incandescent 2 2,849.81 2,955.92 103.72%
lamp, 150W-1500W with OCC
LED Fixture-replacing Halogen/Incandescent 70 1,828,839.71 2,048,494.31 112.01%
lamp, 150W-1500W
LED Retrofit Kit-replacing FLT12: 2ft to 8ft, 34W 18 270,725.02 281,631.82 104.03%
-80W
LED Fixture-replacing T12: 2ft-8ft, 34W-80W 38 258,201.49 296,030.18 114.65%
with OCC
LED Replacement Lamp-replacing
Halogen/Incandescent lamp,20-150W 6 76,532.84 82,924.44 108.35/
LED Fixture-replacing Metal Halide/High
P 63 1,370,179.94 1,414,404.97 103.23%
Pressure Sodium lamp,400W-1000W
LED Fixture-replacing Metal Halide/High 118 1,272,321.39 1,306,642.48 102.70%
Pressure Sodium lamp, 320W-400W
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LED Replacement Lamp-E39 replacing Metal
Halide/High Pressure Sodium lamp, 100W- 6 95,368.32 92,148.47 96.62%
250W
LED Fixture-replacing FLT5:2ft to 8ft, 14W- 12 198,938.10 211,406.63 106.27%
54W with OCC
LED Replacement Lamp-E39 replacing Metal
Halide/High Pressure Sodium lamp,320W- 1 2,340.67 2,261.64 96.62%
400 W
LED Replacement Lamp-replacing CFL Screw- o
in/Pin-based,8W-40W
1 1,746.53 1,687.56 96.62/
LED Retrofit Kit-replacing Halogen/Incandescent 1 1,949.91 2,110.31 108.23%
lamp,20-150W with OCC
LED Replacement Lamp-replacing Metal
Halide/High Pressure Sodium lamp,320W- 1 2,652.21 2,562.67 96.62%
400W
LED Fixture-replacing Metal Halide/High
Pressure Sodium lamp,400W-1000W with OCC 1 257,544.00 254,968.56 99.00%
LED Replacement Lamp-E39 replacing Metal
Halide/High Pressure Sodium lamp,400W- 1 6,779.45 6,550.56 96.62%
1000W
LED Retrofit Kit-replacing FLT5: 2ft to 8ft, 14W- 3 398,272.94 431,033.99 108.23%
54W
LED Fixture-replacing Metal Halide/High 6 270,299.71 363,414.70 134.45%
Pressure Sodium lamp, 320W-400W with OCC
LED Retrofit Kit-replacing FLT12:2ft to 8ft,34W 1 14,675.14 20,104.94 137.00%
-80W with OCC
Total 1,924 18,592,355.85 18,962,968.96 101.99%
The following table summarizes the incentive and non-incentive costs associated with the program.
Table 5-22:Small Business Lighting Program Costs by Measure
Measure Type Measure Incentive Costs Measure Costs
Unit Count
LED Fixture-replacing Metal Halide/High Pressure Sodium
850.00 $389,974.59 $408,548.64
lamp, 100W-250W
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W-
5,869.00 $197,819.17 $209,066.39
59W
LED Fixture-replacing Halogen/Incandescent lamp, 20- 2,765.00 $921,486.16 $957,974.12
150W
LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W 9,194.00 $2,471,064.47 $2,518,258.26
LED Fixture-replacing CFL Screw-in/Pin-based,8W-40W 698.00 $78,425.04 $82,790.22
LED Retrofit Kit-replacing FLT8:2ft to 8ft, 17W-59W 944.00 $189,322.91 $200,760.29
LED Replacement Lamp-replacing FLT12:2ft to 8ft,34W- 2,045.00 $90,058.86 $95,374.87
80W
LED Retrofit Kit-replacing CFL,8W-40W 168.00 $14,233.68 $15,047.77
LED Fixture-replacing FLT5:2ft to 8ft, 14W-54W 1,233.00 $572,844.58 $587,561.61
LED Retrofit Kit-replacing Halogen/Incandescent lamp,20- 2,389.00 $290,620.65 $357,598.47
150W
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LED Fixture-replacing FLT8:2ft to 8ft, 17W-59W with 1,306.00 $357,230.84 $392,608.12
OCC
LED Fixture-replacing T12:2ft-8ft,34W-80W 5,048.00 $1,713,111.97 $1,740,640.44
LED Fixture-replacing Metal Halide/High Pressure Sodium 51.00 $15,176.75 $17,525.47
lamp,< 100W
LED Fixture-replacing Halogen/Incandescent lamp,20- 32.00 $10,817.27 $10,900.94
150W with OCC
LED Replacement Lamp-replacing FLT5:2ft to 8ft, 17W- 1,161.00 $47,828.59 $52,157.50
54W
LED Replacement Lamp-replacing FLT8:2ft to 8ft, 17W- 16.00 $127.64 $410.00
59W with OCC
LED Fixture-replacing Halogen/Incandescent lamp, 150W-
7.00 $1,832.77 $1,832.77
1500W with OCC
LED Fixture-replacing Halogen/Incandescent lamp, 150W- 1,066.00 $835,584.90 $846,255.57
1500W
LED Retrofit Kit-replacing FLT12:2ft to 8ft,34W-80W 626.00 $118,359.76 $126,191.23
LED Fixture-replacing T12:2ft-8ft,34W-80W with OCC 604.00 $153,362.65 $199,292.51
LED Replacement Lamp-replacing Halogen/Incandescent 347.00 $30,425.23 $30,425.23
lamp, 20-150W
LED Fixture-replacing Metal Halide/High Pressure Sodium 619.00 $764,435.52 $785,941.99
lamp,400W-1000W
LED Fixture-replacing Metal Halide/High Pressure Sodium
908.00 $807,554.09 $835,647.45
lamp,320W-400W
LED Replacement Lamp-E39 replacing Metal Halide/High 109.00 $38,143.74 $40,313.00
Pressure Sodium lamp, 100W-250W
LED Fixture-replacing FLT5:2ft to 8ft, 14W-54W with
251.00 $114,129.98 $120,055.54
OCC
LED Replacement Lamp- E39 replacing Metal Halide/High 2.00 $936.27 $936.27
Pressure Sodium lamp,320W-400W
LED Replacement Lamp-replacing CFL Screw-in/Pin-based, 11.00 $698.61 $698.61
8W-40W _
LED Retrofit Kit-replacing Halogen/Incandescent lamp, 20- 7.00 $877.46 $1,267.44
150W with OCC
LED Replacement Lamp-replacing Metal Halide/High 3.00 $1,000.00 $1,000.00
Pressure Sodium lamp,320W-400W
LED Fixture-replacing Metal Halide/High Pressure Sodium 56.00 $167,043.60 $167,043.60
lamp,400W-1000W with OCC
LED Replacement Lamp- E39 replacing Metal Halide/High
Pressure Sodium lamp,400W-1000W 6.00 $2,711.78 $2,711.78
LED Retrofit Kit-replacing FLT5:2ft to 8ft, 14W-54W 338.00 $179,222.82 $179,222.82
LED Fixture-replacing Metal Halide/High Pressure Sodium
159.00 $144,030.29 $183,283.60
lamp,320W-400W with OCC
LED Retrofit Kit-replacing FLT12:2ft to 8ft,34W-80W
28.00 $6,379.27 $6,891.00
with OCC
Total 38,916.00 $10,726,871.91 $11,176,233.52
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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5.3.6.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Small
Business Lighting Program.The evaluated reviewed sampled lighting measures for tracking data
accuracy and also conducted research to ensure facility type was correctly assigned to each customer
included in the sample. Facility type has an impact heating/cooling interactive factors as well as on
lighting control savings, meaning accurate facility type assignment is essential for verified savings
calculations. No major data issues were identified in the tracking data and facility type review of
sampled projects.
5.3.6.2 Impact Analysis
The Evaluators calculated verified savings by using standard engineering algorithms:
Lighting Fixtures
kWh x Wfixt(i)tre
— N XWfixt(i)l x AOH x ISR
savings — [Nf ixt(i) 1000 [ fixt(i) 1000 1 post
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 (varies).Self-reported.
■ 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, assumed to be 100.00% as measures are direct install.
The kWh lighting savings calculated using the above equation were adjusted to take into account
lighting controls, cooling interactive factors, and heating interactive factors, as necessary. Lighting
control savings as well as heating/cooling interactive factors are calculated as a percentage of the kWh
savings presented above, so where appropriate the Evaluators added those adjustments to determine
final verified lighting savings values. Lighting control percentage adjustments as well as heating/cooling
interactive factors vary based on fuel type, lighting installation location, and facility type. Fuel type and
whether or not lighting controls were installed were included in tracking data.The specific percentage
adjustments used in savings calculations were sourced from the RTF Non Residential Lighting calculator
workbook.
5.3.6.3 Verified Savings
The verified savings for the program are 18,962,968.96 kWh with a realization rate of 101.99%, as
displayed in Table 5-21.This difference in expected and verified savings is primarily due to differences in
assigned facility type which contributes to calculated lighting savings. Broadly, expected and verified
savings matched closely leading to a realization rate very close to 100%.
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5.3.7 Non Residential Shell Program
The Non Residential 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 5-23 summarizes the measures rebated in PY2025 under this program.
Table 5-23: Non Residential Shell Program Measures
MethodologyImpact Analysis
Attic Insulation Illinois TRM v12.0 Section 4.8.2
The following table summarizes the verified electric energy savings for the Non Residential Shell
Program impact evaluation.
Table 5-24:Non Residential Shell Program Verified Electric Savings
Project
Measure Count Unit Count Savings Savings
Attic<_ R11 to R45+ 2 14,280.42 10,120.54 1 70.87%
Total 2 14,280.42 10,120.54 70.87%
The following table summarizes the incentive and non-incentive costs associated with the program.
Table 5-25:Non Residential Shell Program Costs by Measure
Measure Square Footage Incentive Costs Measure Costs
Installed
Attic<_R11 to R45+ 26,094.00 $13,883.38 $29,800.00
Total 26,094.00 $13,883.38 $29,800.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Non Residential Shell 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 Non
Residential Shell Program.The Evaluators review all rebate applications to cross-verify tracking data
inputs. 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 5-26 shows
the project population,the number of projects checked and the overall precision.
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Table 5-26:Non Residential Shell Program Verification Precision
2 2 0.0%
All electric projects provided in the program tracking data matched data verified in the rebate
application, and no adjustments to any savings algorithm inputs were necessary. The Evaluators found
all rebate equipment met or exceeded the measure efficiency requirements for the Non Residential
Shell Program.
5.3.7.2 Impact Analysis
This section summarizes the verified savings results for the Non Residential Shell Program.The
Evaluators calculated verified savings for the insulation measures using the Illinois TRM v12.0 Section
4.8.219.The Illinois TRM was selected because it provides engineering algorithms to calculate savings for
commercial roof insulation and commercial wall insulation measures.To estimate savings for attic
insulation measures,the Evaluators applied the algorithm for commercial roof insulation.
The savings algorithms for attic required weather inputs and HVAC equivalent full load hours for various
building types.The Evaluators calculated weather inputs in accordance with the Illinois TRM for weather
the stations in Sandpoint, ID. Equivalent full load heating hours by building type were drawn from Idaho
Power TRM v3.220.
Illinois TRM v12.0 Section 4.8.2 provides the following equations to calculate roof insulation savings:
AkWh = AkW hcooling + AkW hheating
Where:
1 1 Area X EFLHcooling X ATFL,cooling
AkWhcooling = (Rexisting Rnew X 1,000 X 77cooling
AkWhheating
1 _ 1 1 Area X EFLHheating X ATFL,heating
— Rexisting Rnew) X 3,412 X 7heating
• Rexisting = R-value of the existing insulation
■ Rrieu, = R-value of the installed insulation
■ Area = Surface Area of the roof in square feet
■ EFLHcooling = Equivalent Full Load Cooling Hours in the Building
0 ATFL,cooling =Temperature difference during cooling season using a 55° F temperature setpoint
■ 1,000 = Conversion from BTU to kBTU
77cooling = Efficiency of existing cooling system, assumed to be SEER 13
■ EFLHheating = Equivalent Full Load Cooling Hours in the Building
• ATFL,heating =Temperature difference during heating season using a 55° F temperature setpoint
■ 3,412 = Conversion from BTU to kWh
■ hheating = Efficiency of existing furnace, assumed to be 0.78
19 https://www.ilsag.info/wp-content/uploads/IL-TRM-Version-12.0-Volumes-l-4-Compiled-Final.pdf
20 https:Hdocs.idahopower.com/pdfs/EnergyEfficiency/Reports/2020TRM.pdf
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5.3.7.3 Verified Savings
The verified savings for the program are 10,120.54 kWh with a realization rate of 70.87%, as displayed in
Table 5-24.This low realization rate is explained by the fact that the Evaluators employed an
engineering equation with weather inputs specific to Sandpoint, ID to assess measure savings.The
integration of actual 2025 weather data into the verified analysis likely contributed to lower savings
values than generalized estimates used by Avista for expected savings.
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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.
The following table summarizes the verified electric energy savings for the Site-Specific Program impact
evaluation.
Table 5-27.Site-Specific Program Verified Electric Savings
Project Expected Verified Realization
Type of Project
Lighting 6 101,225.00 1 91,700.23 90.59%
Non-Lighting/Other 9 9,746,501.06 9,419,907.14 96.65%
Total 15 9,847,726.06 9,511,607.37 96.59%
The Site-Specific Program displayed verified savings of 9,511,607.37 kWh with a realization rate of
96.59%against the expected savings for the program.
Table 5-28:Site-Specific Program Costs
Type of Project Incentive Costs Measure Costs
Lighting $19,639,61 $72,226.27
Non-Lighting/Other $1,952,256.22 $4,971,840.85
Total $1,971,895.83 $5,044,067.12
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.
5.3.8.1 Sample Design
Given the dramatic variance in energy savings associated with different Site Specific programs,the
Evaluators employed a random stratified sampling approach in which programs were split into strata
based on kWh energy usage buckets and samples were selected from each of those strata to produce a
representative sample that met 90/10 precision goals.The participant population for the Site-Specific
Program was divided into four strata. Table 5-29 summarizes the strata boundaries and sample frames
for the Site-Specific Program.
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Table 5-29:Site-Specific Program Sample Design
statistic
Description Stratum 1 Stratum 2
Strata
4,501— 14,501—
boundaries <4,500 14,500 360,000 >360,000
(kWh)
Number of 2 4 5 4 15
projects
Total kWh 7,563.29 38,329.19 532,884.74 9,268,949.06 9,847,726.28
savings
Average kWh 3,781.65 9,582.30 106,576.95 2,317,237.27 656,515.09
Savings _
Standard
deviation of 773.07 3,404.26 142,010.21 1,418,235.30 1,230,134.70
kWh savings
Coefficient of 0.204 0.355 1.332 0.612 1.874
variation
Final design 0 1 2 4 7
sample
All four sites with savings exceeding 360,000 kWh were specifically selected for verification and analysis.
The verified sampling precision achieved from this sample is 6.48%at 90%confidence.
5.3.8.2 Project Document Review
Once representative projects were selected,the Evaluators obtained all project-related documentation
for review.These documents typically included equipment specification 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 to verify
measure installation and operating parameters, as well as building parameters such as square footage
and HVAC configurations.
5.3.8.3 Impact Approaches
For lighting projects,the evaluators primarily relied on an Option A, engineering analysis approach.The
following equation shows the main calculation used to assess verified savings for lighting projects.
kWh i X Wfixt(i)tre
— [N XWfixt(i)lX AOH X IEF
savings = [Nf xt(i) 1000 fixt(i) 1000 J post
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 or included in project materials)
• Wf ixt(i), post= Rated wattage of post-retrofit fixtures of type i (Taken from project spec sheets)
■ AOH =Annual operating hours for specified space type (Varies. Collected during M&V site visits)
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■ IEF = Site-Specific Interactive effects factor specific to building and Site-Specific configuration
(developed from RTF or project materials)
For non-lighting projects, the Evaluators employed IPMVP Option A-C approaches to calculated verified
savings associated with the Site Specific programs. Evaluators selected the most appropriate IPMVP-
approved methodology based on available data,the percentage of facility savings associated with the
installed measure, and the complexity of the energy efficiency equipment installed.
5.3.8.4 Site-Level Realization
Verified savings were developed for each sampled site.The realization rates for sites within each
stratum were then applied to the non-sampled sites within their respective stratum.Table 5-30 presents
sampled realization at the site level.
Table 5-30:Site-Specific Expected, Adjusted and Verified kWh Savings by Sampled Project
Project ID Expected kWh RealizaWtie
Savings r
SSOP_78933 4,179,306.06 4,179,306.00 100.00%
SSOP_113721 2,371,142.00 2,371,142.00 100.00%
SSO P_117346 1,962,778.00 1,962,778.00 100.00%
SSOP_151517 755,723.00 430,874.00 57.01%
SSOP_140650 62,688.00 75,090.00 119.78%
SSLP_152970 23,402.00 17,185.00 73.43%
SSLP_152961 6,686.00 5,804.00 86.81
Totals: 9,361,725.00 9,042,179.00 96.59%
The overall PY2025 Site-Specific Program in total displays a total of 9,042,179 kWh verified electric
energy savings for sampled projects in the Idaho service territory, as displayed in Table 5-30.
5.3.8.5 Discussion of Non-100%Realization in Sampled Projects
Below are brief explanations of differences between claimed and verified savings for projects with
realization rates that are not 100%.
SSOP_151517—The energy savings calculation information provided utilized an engineering
methodology that could not be reversed engineered with the given documentation.Therefore,
the Evaluators proceeded to conduct an IPMVP Option B analysis by utilizing the AR TRM v9.1
measure for Compressor Replacement.The analysis then yielded a realization rate of 57.01% in
kWh savings.
SSOP_140650—The energy savings were calculated by conducting an IPMVP Option A analysis
utilizing the Non-Residential Lighting Retrofits Protocol from the Regional Technical Forum.The
analysis then yielded a realization rate of 119.78% in kWh savings.
SSOP_152970—The energy savings were calculated by conducting an IPMVP Option A analysis
utilizing the Non-Residential Lighting Retrofits Protocol from the Regional Technical Forum.The
analysis then yielded a realization rate of 73.43% in kWh savings.
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Avista Idaho Electric PY2025 Qualus
■ SSOP_152961—The energy savings were calculated by conducting an IPMVP Option A analysis
utilizing the Non-Residential Lighting Retrofits Protocol from the Regional Technical Forum.The
analysis then yielded a realization rate of 86.81% in kWh savings.
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Avista Idaho Electric PY2025 Qualus
6. Appendices
6.1 Appendix A: Billing Analysis Results
This appendix provides additional details on the billing analyses conducted for each program. 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). Analyses were run focusing specifically on the Idaho service
territory.The billing analysis on individual measures resulted in statistically significant electric impacts
for the Home Energy Audit Program The following section describes the analysis.
6.1.1 Home Energy Audit Program
The results of the billing analysis for the Home Energy Audit are provided below.The Evaluators
identified 98 customers who had only participated in the Home Energy Audit program and no other
energy efficiency programs.These customers were included in a treatment cohort to identify the savings
associated with the Home Energy Audit program in households with electric heating equipment.
The Evaluators were successful in creating a matched cohort for the program with sufficient
participation. Customers were matched on zip code and their average pre-period seasonal usage,
including summer,fall, winter, and spring for each control and treatment household. The Evaluators
were provided with a considerable pool of control customers to draw upon.The Evaluators conducted
propensity score matching(PSM)to match treatment customers to non-participant control customers to
develop cohorts with statistically similar pre-period energy usage.
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. After PSM,t-tests displayed no more
than 2 months with significantly different energy usage at the 95% alpha indicating treatment and
control pre-period energy usage were statistically similar.
The table below provides annual savings per customer and verified program savings for the Home
Energy Audit Program for the Post-Program Regression (PPR) model.Treatment customers included in
the billing analysis participated in this measure only, and therefore no double-counted savings from
other programs need to be accounted for.The total program savings were 32,995.13 kWh saved
annually for treatment customers included in the regression analysis, or 4.41%of annual electric
household consumption.
Table 6-1:Regression Savings, Home Energy Audit Program
ModelAnnual Savings Treatment Program Regression Adjusted R-
804.76 41 32,995.13 0.003 0.893 PPR
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Avista Idaho Electric PY2025 Qualus
6.2 Appendix B: Site Specific M&V Plans and Supplementary
Information
6.2.1 Site Specific M&V Plans
6.2.1.1 SSOP 78933(University of Idaho)
Summary
An energy efficiency project qualified for incentives as part of Avista's commercial custom install
program.The project includes the installation of a micro steam turbine on a university campus.The
system utilizes pressure release valves to power a steam turbine and generate electricity in what would
otherwise be wasted steam production.
M&V Methodology
Motors:Trend data will be collected, and savings will be determined by the amount of electricity being
generated.
Questions To Ask
■ Is there trend data available? If yes, may we have access? Ideally,we need at least a year of
data.
■ Does this system only utilize waste steam that would otherwise be vented, or does it generate
electricity at other times?
■ Is this system impacted by any seasonal factors, such as weather or student populations?Will
that show up in trend data?
■ Verify how many steam turbines were installed
■ What is the total peak capacity the steam turbines can generate?
■ Do the steam turbines have any other impacts than power generation that would impact energy
savings?
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Avista Idaho Electric PY2025 Qualus
6.2.1.2 SSOP 113721 (Clearwater Paper Corporation)
Summary
An energy efficiency project qualified for incentives as part of Avista's commercial custom install
program.The project included the retrofit of DC motors with electronically commutated and variable
frequency drive motors throughout the project site, an industrial facility.
M&V Methodology
Motors: Energy savings will be determined by using trend data obtained from the project site, and
comparing production data with the motor power usage.
Questions To Ask
■ How many motors were installed and how many of each type (IE, 2 ECMs, 1 VFD)
■ What is the total kW/HP of installed motors and baseline motors (if available)?
■ What motor types were replaced?
■ Is there any trend data, and may we have access to it? Ideally 1 year of efficient condition data,
and 1-2 years minimum of the baseline motor systems
■ Is there a specific production process these motors are impacted by? May we have access to
that data to normalize motor trend data with?
■ Are there any other factors that may impact motor operation, such as outdoor weather
conditions?
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Avista Idaho Electric PY2025 Qualus
6.2.1.3 SSOP 151517(Stimson Lumber Company)
Summary
Stimson Lumber Company participated in Avista's energy efficiency program, installing variable speed
controls on one of the formerly fixed speed air compressors servicing the facility.There are (2) rotary-
screw air compressors to serve the facility demands,the primary compressor is undersized, so the
secondary compressor operates to satisfy compressed air demand for the facility.The installation of
variable speed controls for the secondary compressors to reduce capacity while maintaining
compressed air demand.
M&V Methodology
Compressed Air: Ideally air compressor trend data is available for the air compressor.This data will be
used to determine energy consumption over the monitored period. CAGI data sheet for the baseline
compressor will be used in conjunction with trend data to determine equivalent baseline consumption
during monitored period. If trend data is not available,then air consumption data may be used in its
stead, with CAGI data sheets used to determine energy consumption based on compressor capacity.
Questions To Ask
■ What size are the compressors?
■ What is the annual uptime of the air compressors?Are there any instances where the primary
compressor fulfills compressed air demand by itself?
■ Is compressor demand consistent throughout the year or are there any seasonal demand
changes?
■ Request compressor trend data. Ideally would like both pre/post installation. If trend data not
available,then request air consumption data.
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Avista Idaho Electric PY2025 Qualus
6.2.1.4 SSOP 140650(TraderJoes Company)
Summary
This is a grocery store that constructed (17) 47W 2x4 LED fixtures, and (5) 25W 2x2 LED fixtures. The
facility also appears to have retrofitted 162 display case T8 fluorescent fixtures with (162) LED display
lights.
Data Collection
■ Verify installation of all fixtures (see tables). Please take verification photos
■ Confirm the location, quantity, and type of new constructed lighting and retrofitted lighting.
Make sure we only have this site's information since it seems lighting is also being installed with
another tenant.
■ Confirm baseline fixtures type/wattage with site contact and ask if any of the old bulbs are
available for photo.
■ Verify model numbers of new fixtures if possible.
■ Collect HVAC equipment type (cooling and heating)
■ Confirm if controls are present. (i.e., Sensors, switches, etc.)
■ Collect lighting schedules for all rooms where the retrofit was performed.
Lighting Fixture Verification
Lighting Area Fixture Qty Control HVAC Notes
Zone
TDJ-24CZ2-60-U N V-
Store 17
EL14W L850-CD1-U
TDJ-22CZ2-32-U NV
Store 5
L850-CD1-U
TDJ-4SNLED-LD5-
Store 40SL-FUNV-L850- 162
CD1-U
Key
Control Types:Manual Switch(SW),Occupancy Sensor(OS),No Switch/Panel control(PN),Photocell(PC),Daylight Control(DS),or Programmed(EMS)
HVAC types: None,Air Conditioned(AC),Heat Pump(HP),gas,(gas)Refrigerated(Ref),or Freezer(FR). Ex:air conditioned and gas heated=AC/gas
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Avista Idaho Electric PY2025 Qualus
6.2.1.5 SSOP 152970(Jacklin Land Company)
Summary
A manufacturing facility performed a retrofit of (35) 40OW inefficient high bay metal halide lights with
(35) 240W LED high bay lights. The fixtures are installed in Warehouse OF2.
Data Collection
■ Confirm if lights operate on a switch,timer, or sensor. (Note—this site has a sensor recorded on
the invoice, please confirm if the sensor is used for this application).
■ Confirm building type and location of installed lighting.
■ Collect HVAC equipment type (heating and cooling)
■ Verify installation of all fixtures (see tables). Please take verification photos as well.
■ Confirm baseline fixtures type/wattage with site contact and ask if any of the old bulbs are
available for photo.
■ Verify model numbers of new fixtures if possible.
■ Collect lighting schedules for all rooms where the retrofit was performed.
Lighting Fixture Verification
Lighting Area Fixture Qty Control HVAC Notes
Zone
Warehouse OF2 GT-UF03- 35
240WJT2A1-BH40K
Key
Control Types:Manual Switch(SW),Occupancy Sensor(OS),No Switch/Panel control(PN),Photocell(PC),Daylight Control(DS),or Programmed(EMS)
HVAC types: None,Air Conditioned(AC),Heat Pump(HP),gas,(gas)Refrigerated(Ref),or Freezer(FR). Ex:air conditioned and gas heated=AC/gas
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Avista Idaho Electric PY2025 Qualus
6.2.1.6 SSOP 152961 (Raycap Incorporated)
Summary
This is a manufacturing facility that completed an interior lighting retrofit on its facility.
Data Collection
■ Verify installation of all fixtures (see tables)
■ Take verification photos of new lighting fixtures
■ Collect HVAC equipment type
■ Collect hours of operation by fixture set and whether the lighting is in a conditioned area or not
(tables)
Lighting Fixture Verification
Lighting Area Fixture Oty Control HVAC Notes
Zone
Warehouses(indoor) GT-UF03c- 10 none
240WJT2A1-ab40K
Key
Control Types:Manual Switch(SW),Occupancy Sensor(OS),No Switch/Panel control(PN),Photocell(PC),Daylight Control(DS),or Programmed(EMS)
HVAC types: None,Air Conditioned(AC),Heat Pump(HP),gas,(gas)Refrigerated(Ref),or Freezer(FR). Ex:air conditioned and gas heated=AC/gas
Impact Evaluation Report 88

Appendix B: 2025 Natural Gas Impact Evaluation Report

Impact Evaluation of Avista
Utilities' Idaho Gas PY2025
Residential , Low Income, and
Non Residential Energy
Efficiency Programs
Submitted By: Qualus
Submitted On: April 15, 2026
Submitted To: Avista Utilities
Qualus Avista Utilities
100 Colonial Center Parkway, Suite 400 1411 E. Mission Ave.
Lake Mary, FL 32746 Spokane, WA 99252

Avista Idaho Gas PY2025 Qualus
Table of Contents
1. Executive Summary..............................................................................................................................5
1.1 Savings Results............................................................................................................................................5
1.2 Conclusions and Recommendations...........................................................................................................6
2. General Methodology........................................................................................................................11
2.1 Glossary of Terminology...........................................................................................................................11
2.2 Summary of Approach..............................................................................................................................12
3. Residential Impact Evaluation Results...............................................................................................26
3.1 Simple Verification Results.......................................................................................................................26
3.2 Program-Level Impact Evaluation Results................................................................................................28
4. Low Income Impact Evaluation Results..............................................................................................43
4.1 Simple Verification Results.......................................................................................................................43
4.2 Program-Level Impact Evaluation Results................................................................................................45
5. Non Residential Impact Evaluation Results........................................................................................49
5.1 Database& Document Verification..........................................................................................................49
5.2 Program-Level Impact Evaluation Results................................................................................................51
6. Appendices.........................................................................................................................................58
6.1 Appendix A: Billing Analysis Results.........................................................................................................58
6.2 Appendix B:Site Specific M&V Plans........................................................................................................59
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Avista Idaho Gas PY2025 Qualus
List of Tables
Table 1-1: Residential Verified Impact Savings by Program .........................................................................5
Table 1-2: Low Income Verified Impact Savings by Year..............................................................................5
Table 1-3: Non Residential Verified Impact Savings by Program..................................................................6
Table 2-1: Document-based Verification Samples and Precision by Program ...........................................16
Table 2-2: Survey-Based Verification Sample and Precision by Program...................................................17
Table 3-1: Residential Verified Impact Savings by Program .......................................................................26
Table 3-2: Residential Costs by Program ....................................................................................................26
Table 3-3: Residential ISRs by Measure......................................................................................................27
Table 3-4: Appliances Program Measures ..................................................................................................28
Table 3-5:Appliances Program Verified Gas Savings..................................................................................29
Table 3-6:Appliances Program Costs by Measure .....................................................................................29
Table 3-7: ENERGY STAR° Homes Program Measures ...............................................................................31
Table 3-8: ENERGY STAR' Homes Program Verified Gas Savings...............................................................31
Table 3-9: ENERGY STAR° Homes Program Costs by Measure...................................................................31
Table 3-10: Fuel Conversion Program Measures........................................................................................33
Table 3-11: Fuel Conversion Program Verified Gas Savings .......................................................................33
Table 3-12: Fuel Conversion Program Costs by Measure...........................................................................33
Table 3-13: Home Energy Audit Program Verified Gas Savings..................................................................35
Table 3-14: Home Energy Audit Program ...................................................................................................36
Table 3-15: Midstream Program Measures................................................................................................37
Table 3-16: Midstream Program Verified Gas Savings ...............................................................................37
Table 3-17: Midstream Program Costs by Measure...................................................................................38
Table 3-18: Shell Program Measures..........................................................................................................39
Table 3-19: Shell Program Verified Gas Savings .........................................................................................40
Table 3-20: Shell Program Costs by Measure.............................................................................................40
Table 4-1: Low Income Verified Impact Savings by Program Year .............................................................43
Table 4-2: Low Income Costs by Program Year...........................................................................................43
Table 4-3: Low Income Program Measures ................................................................................................45
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Avista Idaho Gas PY2025 Qualus
Table 4-4: PY2024 Low Income Program Claimed Gas Savings ..................................................................46
Table 4-5: PY2024 Low Income Program Claimed Costs by Measure ........................................................46
Table 4-6: PY2025 Low Income Program Claimed Gas Savings ..................................................................47
Table 4-7: PY2025 Low Income Program Claimed Costs by Measure ........................................................47
Table 5-1: Non Residential Verified Impact Savings by Program................................................................49
Table 5-2: Non Residential Costs by Program.............................................................................................49
Table 5-3: Non Residential Midstream Program Measures........................................................................52
Table 5-4: Non Residential Midstream Program Verified Gas Savings.......................................................52
Table 5-5: Non Residential Midstream Program Costs by Measure...........................................................53
Table 5-6: Non Residential Shell Program Measures..................................................................................54
Table 5-7: Non Residential Shell Program Verified Gas Savings.................................................................54
Table 5-8: Non Residential Shell Program Costs by Measure.....................................................................54
Table 5-9: Non Residential Shell Program Verification Precision ...............................................................55
Table 5-10: Site-Specific Program Verified Gas Savings..............................................................................56
Table 5-11: Site-Specific Program Costs .....................................................................................................56
Table 5-12: Site-Specific Expected,Adjusted and Verified therms Savings by Project...............................57
Table 6-1: Regression Savings, Natural Gas Furnace..................................................................................58
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Avista Idaho Gas PY2025 Qualus
1. Executive Summary
This report is a summary of the impact evaluation of Avista Utilities' (Avista) 2025 program year
(PY2025) Residential, Low Income, and Non Residential Gas Energy Efficiency Portfolio in the Idaho
service territory. The evaluation, measurement, and verification (EM&V) of PY2025 Idaho Gas
portfolio was administered by Qualus, a leading pure-play power services firm. (herein referred to as
the "Evaluators").
1.1 Savings Results
The Evaluators conducted an impact evaluation for Avista's Residential, Low Income, and Non
Residential programs for PY2025.The Residential portfolio savings amounted to 163,004.90 therms
with a 93.90% realization rate. The PY2025 Low Income portfolio savings amounted to 3,832.95
therms for a realization rate of 99.13%. Of note,the Evaluators also assessed PY2024 savings
associated with the Low Income program. The PY2025 Non Residential portfolio savings amounted
to 31,143.27 therms with 97.83% realization rate.The Evaluators summarize the Residential, Low
Income, and Non Residential portfolio verified savings in Table 1-1 through Table 1-3, respectively.
Table 1-1: Residential Verified Impact Savings by Program
Expected Verified
"Progra m- Project Savings Savings Realization Incentive
I Count (therms) (therms) Rate Costs
Appliances 1 283 5,594.57 4,123.11 73.70% $29,194.29
ENERGY STAR Homes 2 267.96 300.96 112.32% $1,200.00
Fuel Conversion 11 -5,403.00 -5,403.00 100.00% $0.00
Home Energy Audit 190 0.00 0.00 NA $0.00
Residential Midstream 1,891 147,030.50 142,774.86 97.11% $738,100.00
Residential Shell 631 26,097.37 21,208.97 81.27% $439,431.49
Residential Total 3,008 173,587.40 163,004.90 93.90% $1,207,925.78
Table 1-2:Low Income Verified Impact Savings by Year
Program Expected Verified Realization Incentive
Year Project Count Savings Savings Rate Costs
(therms) (therms)
2024 39 1,380.11 1,283.79 1 93.02% 1 $186,029.73
2025 83 3,866.78 3,832.95 99.13% $476,683.88
Total 122 5,246.89 5,116.74 97.52% $662,713.61
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Avista Idaho Gas PY2025 Qualus
Table 1-3:Non Residential Verified Impact Savings by Program
Project Expected Verified Realization Incentive
Program Count Savings Savings Rate Costs
(therms) (therms)
Non Residential Midstream 79 28,201.96 28,136.73 99.77% $106,564.00
Non Residential Shell 2 628.42 168.53 26.82% $5,909.12
Site Specific-Other 2 3,003.00 2,838.00 94.51% $10,508.75
Total 83 31,833.38 31,143.27 97.83% $122,981.87 J
Details on the varied methodologies used to calculate verified savings associated with each measure can
be found in the Residential, Low Income, and Non Residential program-level impact evaluation results
sections below.
1.2 Conclusions and Recommendations
The following section details the Evaluators' conclusions and recommendations for each the Residential,
Low Income, and Non Residential program evaluations.
1.2.1 Conclusions
Key program-specific and overarching conclusions are presented in the following subsections.
1.2.1.1 Residential Programs
The Evaluators provide the following conclusions regarding Avista's Residential gas programs:
■ The Evaluators found the Residential Portfolio had total verified savings of 163,004.90 therms
with a realization rate of 93.90%. This suggests strong consistency in expected and verified
savings methodologies, particularly so for the Residential Midstream program which made up
over 87%of total verified residential savings.
■ The Appliances and Residential Shell programs yielded realization rates of 73.70%and 81.27%,
respectively. Lower realization rates for these programs were driven by differences in the
granularity of the Northwest Power and Conservation Council's Regional Technical Forum (RTF)
measure deemed savings estimates as compared to the expected values employed by Avista.
The RTF differentiates deemed savings values by a variety of factors including location (per RTF
heating/cooling zone), installed equipment efficiency(e.g., window U-factor, insulation R-value,
appliance ENERGY STAR most efficient certification), heating fuel (e.g., gas vs. electric), and
household heating equipment type (e.g., furnace vs. boiler). In contrast, Avista's expected
savings values were more often averaged values with less differentiation by the aforementioned
factors. While less granularity in measure differentiation can make it more straightforward to
determine ex-ante savings, averaged values can be less precise than the RTF's savings
differentiation.This difference in deemed savings value differentiation was a key driver of lower
realization rates. In addition to this difference in methodological granularity,the Evaluators also
found several instances in which installed equipment did not meet claimed efficiency standards
which also contributed to lower program-wide realization rates.
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Avista Idaho Gas PY2025 Qualus
■ The ENERGY STAR Homes Program yielded a realization rate of 112.32% primarily due to the
fact that expected savings seem to have been calculated based on an average of the RTF's
deemed savings values for heating zones 1-3, while the Evaluators calculated verified savings
based on the participants' actual location and heating zone.
■ The Fuel Conversion Program yielded verified savings of-5,403.00 therms for a realization rate
of 100.00%.The negative gas savings associated with this program are offset by decreased
electric usage due to outdated electric heating equipment being converted to efficient gas
equipment.
■ The Home Energy Audit Program did not include expected savings and as such has no realization
rate.The program did not yield statistically significant savings per a billing analysis and as such
the 190 gas participants have been assigned zero therm savings for PY2025.
■ The Residential Midstream Program yielded verified savings of 142,774.86 therms with a
realization rate of 97.11%.Across 2024 and 2025 the Evaluators have collaborated with Avista to
review and verify the methodologies used to develop the midstream section of Avista's TRM.
This realization rate of close to 100% highlights Avista's accurate application of reviewed savings
values across the Midstream program. Deviations from a 100% realization rate were primarily
due to minor differences in expected and verified savings values for gas furnaces. Expected
furnace savings were based on a treatment-only billing data regression analysis run in July 2025
while verified furnace savings were based on a post-program regression (PPR) regression
analysis run in March 2026.
1.2.1.2 Low Income Programs
The Evaluators provide the following conclusions regarding Avista's Low Income gas program:
■ The verified savings for the Low Income Program in PY2024 are 1,283.79 therms with a
realization rate of 93.02%.
■ The verified savings for the Low Income Program in PY2025 are 3,832.95 therms with a
realization rate of 99.13%.
■ Differences between reported and verified savings were primarily driven by data limitations,
including inconsistencies in the measure quantity field, the need to apply Single Family RTF
values for Manufactured and Multifamily homes, and missing details such as exterior door
square footage and installed window type, both of which required conservative assumptions.
1.2.1.3 Non Residential Programs
The Evaluators provide the following conclusions regarding Avista's Non Residential gas programs:
■ The Evaluators found the Non Residential portfolio had total verified savings of 31,143.27
therms with a realization rate of 99.13%.All programs except for the Non Residential Shell
program had realization rates between 94%and 100%, while the Non Residential Shell program
had a 26.82% realization rate. Broadly there was good consistency between expected and
verified savings for the Non Residential portfolio.
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Avista Idaho Gas PY2025 Qualus
■ The Non Residential Midstream Program yielded a realization rate of 99.77% highlighting
excellent concordance between expected and verified savings values. Slight differences in
assumed savings calculation parameters for instantaneous water heaters led to a 91.72%
realization rate for that measure which decreased program-wide savings down to 99.77%
instead of a perfect 100%.
■ The Non Residential Shell Program had a realization rate of 26.82%.This low realization rate is
explained by the fact that verified savings methodologies integrated actual 2025 weather data
into savings calculations while expected savings methods did not seem to. Ultimately,
differences in the parameters and assumptions of expected and verified engineering equations
seem to have contributed to this lower realization rate.
■ The Site Specific program yielded an overall realization rate of 94.51%, suggesting strong
consistency in ex-ante and ex-post evaluation methodologies across most custom projects. One
project had an expected engineering methodology that could not be reverse engineered which
forced the Evaluators to rely on deemed savings estimates to calculate verified savings.This
difference in methodology contributed to a realization rate slightly lower than 100%.
1.2.2 Recommendations
Key program-specific and overarching recommendations are presented in the following subsections.
1.2.2.1 Residential Programs
The Evaluators offer the following recommendations regarding Avista's Residential gas 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.
■ The Evaluators also found several instances in which RTF heating zone or household heating fuel
included in the tracking data did not match rebate documentation.The Evaluators would
recommend Avista regularly review tracking data and compare it to available databases to
improve accuracy where possible.
■ In addition,there were many instances in which Avista's expected savings values did not align
with the more granular estimates included in RTF unit energy savings workbooks.The Evaluators
appreciate there is a balance between the ease of applying a single savings value to an installed
measure and the improved precision of differentiating savings based on a variety of factors.
However, at a minimum the Evaluators would recommend differentiating savings based on
location (e.g., via RTF heating/cooling zone) and measure efficiency in the future to ensure
expected savings values are as precise as possible.
■ Lastly,the Evaluators would suggest Avista include key fields in tracking data across all
programs. Certain fields are always used in savings evaluation and without them simplifying
assumptions are often required which may reduce the accuracy of savings estimates.The
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Avista Idaho Gas PY2025 Qualus
Evaluators appreciate that customers may not completely fill out rebate application forms,
which may make tracking data completeness a challenge; however,tracking data should ideally
include the following fields at a minimum:
o A unique identifier for each measure installed
o Household space heating fuel and equipment type (e.g.,furnace vs. boiler)
o Household water heating fuel and equipment type
o Household address including zip code
o Whether or not the household has cooling equipment
o Measure installation quantity and square footage for relevant measures like windows
and insulation
o Measure baseline conditions including efficiency and configuration (e.g.,the type of
windows being replaced—single vs. double pane)
o Installed measure equipment efficiency and configuration
o Installed measure equipment model numbers
o Expected savings estimates
o Incentive and measure costs associated with the installed equipment
1.2.2.2 Low Income Programs
The Evaluators offer the following recommendation regarding Avista's Low Income gas programs:
■ To improve the accuracy and efficiency of future EM&V efforts for the Low-Income Program,the
Evaluators recommend enhancing the tracking system to include consistent, measure-specific
data fields and to capture key attributes required for RTF savings calculations, such as installed
window characteristics and exterior door dimensions. Standardizing how measure quantities are
recorded across all measure types would reduce ambiguity and prevent the need for
assumptions during verification.Additionally, incorporating checks for measure eligibility
criteria—such as ENERGY STAR certification for storage tank water heaters—would help ensure
that only qualifying installations are reported with savings. These improvements would
strengthen data quality, reduce reliance on assumptions, and support more accurate realization
rates in future program years.
1.2.2.3 Non Residential Programs
The Evaluators offer the following recommendations regarding Avista's Non Residential gas programs:
■ The Evaluators found several instances in which RTF heating zone or household heating fuel
included in the tracking data did not match rebate documentation.The Evaluators would
recommend Avista regularly review tracking data and compare it to available databases to
improve accuracy where possible.
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Avista Idaho Gas PY2025 Qualus
■ The Evaluators would suggest Avista include key fields in tracking data across all programs.
Certain fields are always used in savings evaluation and without them simplifying assumptions
are often required which may reduce the accuracy of savings estimates.The Evaluators
appreciate that customers may not completely fill out rebate application forms, which may
make tracking data completeness a challenge; however, tracking data should ideally include all
the fields detailed above in the Residential Programs recommendations section.
■ For the Site Specific Program,the Evaluators would recommend Avista share expected savings
Excel calculators/tools wherever possible to ensure verified savings are calculated based on the
most complete information possible.While tracking data and rebate documentation PDFs both
provide useful details for verified savings calculations, given the complexity of some custom
measures, having access to all ex-ante Excel calculators would be useful for future savings
estimation.
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2. General Methodology
The Evaluators performed an impact evaluation on each of the programs summarized in Avista's Idaho
gas portfolio.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:
■ Simple verification (web-based 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 for each the electric impacts and the natural gas
impacts for projects completed in the Idaho Avista service territory. For the purposes of this report, only
the Idaho Gas impacts are quantified and reported.
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 20134
■ International Performance Measurement and Verification Protocol (IPMVP) maintained by the
Efficiency Valuation Organization (EVO) with sponsorship by the U.S. Department of Energy
(DOE)5
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:
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 Qualus(formerly 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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■ 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.
■ 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 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 Non Residential programs.The Evaluators start by presenting our
general evaluation approach.This chapter is organized by general task due to substantial overlap across
programs.
The Evaluators outline the approach to verifying, measuring, and reporting the residential portfolio
impacts as well as cost-effectiveness and 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 2026 program
year and onwards.
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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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 and Small Business 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 may also be
employed, depending upon the project. Specific methods are discussed in each site report.
The Evaluators aimed to accomplish 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;
■ Where available data exists, conduct billing analysis with a suitable comparison group to
estimate measure savings; and
■ Use IPMVP analysis methods for custom projects.
The Evaluators calculated verified savings for each measure based on the RTF UES, Avista TRM, or an
IPMVP-approved methodology (such as an Option C billing analysis) in combination with the results from
document review. For the Appliances, ENERGY STAR Homes, Residential Shell, Green Motors, and
Prescriptive Lighting Programs,the Evaluators also applied in-service rates (ISRs)from verification
surveys.The following flow chart outlines the process by which the Evaluators progress from reported
savings to verified savings.
Reported Database Document Verified
Savings Review r 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.
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.
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Measure-level net savings were evaluated primarily by reviewing measure algorithms and values in the
tracking system to ensure appropriate, error-free savings estimates were included in the tracking data.
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 projects were
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
2.2.2.2 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 = (ZXCV)Z
d
Equation 2-2:Sample Size for Finite Population Size
n
no = (( ll
1 + `Nl
Where,
■ n =Sample size
■ Z =Z-value for a two-tailed distribution at the assigned confidence level.
■ CV = Coefficient of variation
■ d = Precision level
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■ 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.
2.2.2.3 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
that have 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.
2.2.2.4 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.
■ Appliances Program
■ ENERGY STAR' Homes Program
■ Fuel Conversion Program
■ Residential Midstream Program
■ Residential Shell Program
■ Low Income Program
6 Assumption based off California Evaluation Framework:
https://www.cpuc.ca.gov/uploaded Files/CPUC_Public_Website/Content/UtiIities_and_I ndustries/Energy/Energy_Programs/De
mand_Side_Management/EE_and_Energy_Savings_Assist/CAEvaluationFramework.pdf
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■ Non Residential Midstream Program
■ Non Residential Shell Program
■ Site Specific 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 Database Review& Document Verification sections presented for
each program.
Meanwhile the Home Energy Audit program was evaluated based on a comprehensive review of billing
data as well as tracking data from current and previous evaluations.
The Evaluators developed a sampling plan that aimed to achieve 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 (With Finite Precision at 90%Cl
Population Population
Residential Appliances 283 57 90%±9.74%
Residential ENERGY STAR Homes 2 2 90%±0.00%
Residential Fuel Conversion 11 11 90%±0.00%
Residential Residential Midstream 1,811 839 90%±2.08%
Residential Residential Shell 631 65 90%±9.66%
Low Income Low Income 60 32 90%±9.93%
Non Residential Non Residential Midstream 79 17 90%±8.83%
Non Residential Non Residential Shell 2 2 90%±0.00%
Non Residential Site Specific 2 2** 90%±0.00%
*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 Site-Specific Program sample is distinct from other sampling methodologies presented in this table as it is chosen via a
random stratified sample. However,it is included in this table for illustrative and informative purposes.
The table above represents the number of rebates in Idaho service territory only(does not include Idaho
rebate samples).The Evaluators ensured representation of state and fuel type in the sampled rebates
for document verification.
2.2.2.5 Survey-Based Verification
The Evaluators conducted survey-based verification for the Appliances program, Residential Shell
program, and the Prescriptive Lighting program in PY2025.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 shown in Table 2-2 for the Residential Appliance and
Non Residential Lighting Programs.The Evaluators developed a sampling plan that achieved a sampling
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precision of±4.62% at 90%statistical confidence for residential ISRs estimates at the program-level
during web-based survey verification.
Table 2-2:Survey-Based Verification Sample and Precision by Program
Sector Program Population Respondents 7Precision at 90%CI
Residential Appliances 2,911 160 J 90%±6.32%
Residential Shell 6,115 146 90%±6.73%
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. For all programs in which in-service rates were not identified via survey-based verification,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 in the calculation of verified savings values.
2.2.2.6 On-Site Visits
For the 2025 evaluation,the Evaluators did not conduct any on-site visits as available tracking data and
rebate documentation contained all required data for verification.
2.2.3 Impact Evaluation Methodology
The Evaluators employed the following approach to complete impact evaluation activities for all
programs except Site Specific.The Evaluators define two major approaches to determining net savings
for Avista's programs:
■ Deemed Savings
■ Partial Retrofit Isolation Engineering Equation (IPMVP Option A)
■ Billing Analysis (IPMVP Option C)
In contrast, the Site-Specific program also employed various IPMVP options, based on available data and
the energy efficiency measures being installed.This approach is discussed separately in the Site Specific
Program section 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 the deemed savings and billing analysis approaches.
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. Per RTF UES workbook guidelines,the Evaluators differentiated
savings based on customer heating/cooling zone and other key measure/household data like equipment
efficiency and heating fuel type,where appropriate and available.
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The Evaluators requested and used the technical reference manual Avista employed during calculation
of ex-ante measure savings (Avista TRM)for limited measures where an appropriate RTF UES measure
workbook (or other valid methodology)was not available. Of note, based on extensive discussions with
Avista and its Midstream program implementer,Avista TRM values were used to verify both Residential
and Non Residential Midstream measures.These midstream measure Avista TRM savings values were
thoroughly vetted by the Evaluators across 2024 and 2025.
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 Partial Retrofit Isolation Engineering Equation
For select measures where an RTF UES measure workbook was not available,the Evaluators employed
simple engineering equations to identify measures savings.This methodology is consistent with IPMVP
Option A partial retrofit isolation. Valid engineering equations were identified using reputable sources
such as the Illinois TRM version 12.'Wherever possible, Pacific Northwest-specific inputs were used in
these engineering equations to ensure verified savings estimates were regionally relevant.
2.2.3.3 Billing Analysis
This section describes the billing analysis methodology employed by the Evaluators as part of impact
evaluation activities. In most cases, the Evaluators performed billing analyses with a matched control
group, utilizing 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 necessary to produce a matched control
cohort. Where a valid matched control group could not be developed,the Evaluators employed a
treatment-only regression analysis.
For the purposes of this analysis, a household is considered a treatment household if it has participated
in an energy efficiency program. Meanwhile, a household is considered a control household if the
household has not participated in an energy efficiency program during the relevant analysis period.To
isolate measure impacts,treatment households are eligible to be included in the billing analysis if they
installed only one measure during the 2025 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 feasible to identify.Therefore,
instances where households installed isolated single measures were used in the billing analyses.
Before delving further into the specifics of the Evaluators' billing analysis methodology, it is important to
clarify a few key definitions. In the context of a billing analysis, the pre-period identifies the period prior
to measure installation while the post-period refers to the period following measure installation. In the
regressions run by the Evaluators the pre-period and the post-period were both 12 months meaning the
overall analysis period was 24 months.
7 https://www.ilsag.info/wp-content/uploads/IL-TRM-Version-12.0-Volumes-1-4-Compiled-Final.pdf
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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 as well as other variables like 3-digit zip code.
Similarity between treatment customers and matched controls can be verified via statistical difference
testing. After developing a matched cohort via PSM, 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 comparable 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 perfectly matched control group, the inclusion of a
control group via PSM allows billing analyses to control for external factors that might affect energy
usage. Some examples of external factors that might impact energy usage include changes in the
economy(e.g., a recession), large-scale societal changes (e.g., a pandemic), or major weather-related
anomalies such as flooding or hurricanes. If such external factors are not present,then a treatment-only
regression analysis can also be a valid methodology to determine measure-level savings.
After PSM,the Evaluators ran the following regression models for each measure included in the billing
analysis:
■ 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)
After running these regressions,the Evaluators determined the most appropriate model base on a
review of key metrics such as model fit (per adjusted R-squared), model significance (i.e., a p-value<_
0.05), and average savings values. Further details on regression model specifications can be found
below.
8 National Renewable Energy Laboratory(NREL)Uniform Methods Project(UMP)Chapter 17 Section 4.4.7.
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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,
2024 and December 31, 2025)
5. Typical Meteorological Year(TMY3) data
Billing and weather data were obtained for program year 2025 and for one year prior to measure install
dates (2024).
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 a given program and installed a given
measure.
2. Excluded participant homes that also participated in other programs or installed other energy
efficiency measures.
3. Gathered billing data for similar customers that did not participate any energy efficiency
programs.
4. Excluded bills missing address information, if any were identified.
5. Removed bills missing fuel type/Unit of Measure (UOM) information, if any were identified.
6. Removed bills missing usage, billing start date, or billing end date, if any were identified.
7. Remove bills with outlier durations (<9 days or>60 days) , if any were identified.
8. Excluded bills with consumption indicated to be outliers, if any were identified.
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 02/19/2025 start date,
overlapping bill 2 had a 02/25/2025 start date, and the previous bill had a 02/19/2025 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.
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10. Calendarized bills (this involves recalculating 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 the 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.
For this analysis the Evaluators assigned a setpoint of 65°F for both HDD and CDD.
13. Removed measure cohorts without at least 75 treatment customers.
14. Selected treatment customers with only one measure installed during the analysis period and
added measure install dates to the billing data dataset(to define pre-and post-periods).
15. Removed customers with incomplete post-period billing data (<6 months).
16. Removed customers with incomplete pre-period billing data (<10 months).
17. Restricted control customers to those with usage that was comparable with the treatment
group usage.
18. 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. In most cases,the Evaluators selected either Model 1 or Model 2
to identify verified net savings. However, the Evaluators also considered Model 3 since treatment-only
regression analyses can also provide valid savings estimates, especially if major external factors (e.g., a
pandemic) are unlikely to affect broader trends of customer energy usage (as is the case in Idaho across
2024 and 2025).
2.2.3.3.1.1 Modell:Fixed Effects Difference-in-Difference Regression Model
The following equation displays the first model specification used to estimate the average daily savings
associated with each energy efficiency measure included in the billing analysis.
Equation 2-3:Fixed Effects Difference-in-Difference (D-n-D)Model Specification
ADCit = ao +f31(Post)it +f32(Post x Treatment)it +f33(HDD)it +f34(CDD)it
+fl5(Post x HDD)it +&(Post x CDD)it +f34Post x HDD x Treatment)it
+#8(Post x CDD x Treatment)it +f g(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
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■ 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
■ 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.f32 represents the average change in daily usage in the post-period between
the treatment and control group and Q7 and Qs 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 = f32 * 365.25 +f37 * TMY HDD +f38 * TMY CDD
2.2.3.3.1.2 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:
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Equation 2-5:Post-Program Regression (PPR)Model Specification
ADCit = ao +f31(Treatment)i +F'2 (PreUsageSpring)i +f33(PreUsageSummer)i
+f34(PreUsageFall)i +f35(PreUsageWinter)i + &(Month)t
+f37(Month x PreUsageSpring)it + MlUonth x PreUsageSummer)it
+f39(Month x PreUsageFall)it +f31o(Month x PreUsageWinter)it +Qll(HDD)it
+f312(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
■ 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)
■ Eit = Customer-level random error
■ ao=The model intercept for home i
■ F'1-14 = Coefficients determined via regression
The coefficient#, represents the average change in consumption between the pre-period and post-
period for the treatment group and f313 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 f313 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 = F'1 * 365.25 +f313 * TMY HDD + F'14 * TMY CDD
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Avista Idaho Gas PY2025 Qualus
2.2.3.3.1.3 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,treatment-only regression analyses (i.e., those not
including a counterfactual comparison group) can also be an extremely useful tool for estimating energy
savings. One advantage of a treatment-only regression is it does not rely on quasi-experimental
methods (i.e., PSM)to develop a control cohort. Depending on available non-participant billing data, it
can be difficult to develop a valid matched control cohort. Especially if sufficient non-participant data is
not available to develop an appropriate control group,gross savings calculated via a treatment-only
regression can provide valid measure-level energy savings estimates.A treatment-only regression
analysis does not include control group billing data, instead it focuses exclusively on the differences in
energy usage between the pre-period and post-period for program participants.
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 +Ql(Post)it +fl2(HDD)it +R3(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
■ Customer Dummyi =a customer-specific dummy variable isolating individual household
effects
■ Eit = 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
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Avista Idaho Gas PY2025 Qualus
like a pandemic or recession,they still provide meaningful estimates of changes in energy usage
associated with measure installation.
2.2.4 Net-To-Gross
The Pacific Northwest RTF UES measures do not require Net-To-Gross (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, do not require a NTG adjustment, as the counterfactual
represents the efficiency level at the 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 Gas PY2025 Qualus
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 PY2025.The following sections summarize gas impact evaluation
findings for 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
Now— —I Expected Saving—s'?Verified Savin_gS_7_____.
Program _A rF4jict C�ount (therms) (therms) Realization Rate
Appliances 283 5,594.57 4,123.11 73.70%
ENERGY STAR Homes 2 267.96 300.96 112.32%
Fuel Conversion 11 -5,403.00 -5,403.00 100.00%
Home Energy Audit 190 0.00 0.00 NA
Residential Midstream 1,891 147,030.50 142,774.86 97.11%
Residential Shell 631 26,097.37 21,208.97 81.27%
Residential Total 3,008 173,587.40 163,004.90 93.90%
The following table presents residential incentive and measures costs by program. As outlined in the
following program-specific sections, in some cases tracking data did not include complete measure cost
information and if that was the case,the Evaluators assumed measure costs were identical to gas
incentive costs. For the Home Energy Report program, no cost information was included in the tracking
data and as such incentive and measure costs were assumed to be $0.00. For the Fuel Conversion
program, incentive and measure costs were counted in the Evaluators' Idaho Electric report and as such
gas incentive and measure costs were assigned to zero.
Table 3-2: Residential Costs by Program
Incentive Costs T Measure Costs
Appliances $29,194.29 $133,633.03
ENERGY STAR Homes $1,200.00 $110,000.00
Fuel Conversion $0.00 $0.00
Home Energy Audit $0.00 $0.00
Home Insulation Program $738,100.00 $738,100.00
Residential Midstream $439,431.49 $6,293,704.65
Residential Total $1,207,925.78 $7,275,437.68
3.1 Simple Verification Results
The Evaluators surveyed customers participating in Avista's PY2025 Appliances and Residential Shell
program and received sufficient responses to hit 90/10 precision. Details on program populations and
survey responses can be found in the Survey-Based Verification section above. Results and findings from
these surveys and other process evaluation activities can be found in the Evaluators' separate process
report. For the purposes of this impact report, the key finding from this survey-based verification activity
is the identification of in-service rates.
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3.1.1 In-Service Rates
The Evaluators calculated in-service rates (ISRs) of installed measures from simple verification surveys
deployed to program participants in the Appliances and Residential Shell programs.The Evaluators
asked participants if the rebated equipment is currently installed and working. Measure-specific in-
service rates for the Idaho service territory can be found in the following table. The Evaluators assumed
an in-service rate of 100%for any measures not included in the following table.
Table 3-3:Residential ISRs by Measure
Measure .. Methodology
ENERGY STAR Clothes Washer 15 100% Verification survey
Appliances ENERGY STAR Clothes Dryer 17 100% Verification survey
Glass Door 20 100% Verification survey
Shell Insulated Door 7 100% Verification survey
Windows 59 100% Verification survey
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 survey responses are included in a separate process
analysis report.
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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 Appliances Program
The Appliances Program is a residential prescriptive program that offers incentives for customers to
upgrade their existing clothes washers/dryers, refrigerators/freezers, and smart thermostats to ENERGY
STAR-rated products. Primary multifamily homes with shared interior walls including apartments,
duplexes, townhomes, and condos have no minimum usage requirement. Seasonal and recreational
homes are not eligible.
This section summarizes the impact results of the evaluation results for the Appliances Program. Table
3-4 summarizes the measures offered under this program.
Table 3-4:Appliances Program Measures
'06- Description Impact Analysis
40-1 Methodology
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 Smart Thermostat DIY with Gas ENERGY STAR-certified Smart Thermostat RTF UES
Heat with DIY install for residential homes
G Smart Thermostat Paid Install with ENERGY STAR-certified Smart Thermostat RTF UES
Gas Heat with Paid Install for residential homes
Multifamily G Energy Star Rated ENERGY STAR-certified front-loading clothes RTF UES
Clothes Dryer washer for residential homes
Multifamily G Energy Star Rated ENERGY STAR-certified Smart Thermostat RTF UES
Front Load Washer with DIY install for residential homes
Multifamily G Smart Thermostat DIY ENERGY STAR-certified Smart Thermostat RTF UES
with Natural Gas Heat with Paid Install for residential homes
The following table summarizes the verified gas energy savings for the Appliances Program impact
evaluation.
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Table 3-5:Appliances Program Verified Gas Savings
Project lExpected Verilied Realization
Measure Savings Savings
Count (therms) (therms) Rate
SF G Energy Star Rated Clothes Dryer 34 95.20 56.00 58.82%
SF G Energy Star Rated Front Load Washer 56 343.71 487.67 141.88%
SF G Smart Thermostat DIY with Natural Gas 124 3,370.58 1,965.11 58.30%
Heat
SF G Smart Thermostat Paid Install with
62 1,704.96 1,581.93 92.78%
Natural Gas Heat
MF G Energy Star Rated Clothes Dryer 1 2.72 1.60 58.82%
MF G Energy Star Rated Front Load Washer 4 24.12 30.80 127.69%
MF G Smart Thermostat DIY with Natural Gas 2 53.28 0.00 0.00%
Heat
Total 283 5,594.57 4,123.11 73.70%
The Appliances Program displayed verified savings of 4,123.11 therms with a realization rate of 73.70%
against the expected savings for the program.The following table summarizes the incentive and non-
incentive costs associated with the program.
Table 3-6:Appliances Program Costs by Measure
Measure Incentive Measure
Costs Costs
SF G Energy Star Rated Clothes Dryer $1,750.00 $30,457.98
SF G Energy Star Rated Front Load Washer $2,850.00 $50,565.42
SF G Smart Thermostat DIY with Natural Gas Heat $14,563.31 $19,172.55
SF G Smart Thermostat Paid Install with Natural Gas Heat $9,530.98 $29,295.32
MF G Energy Star Rated Clothes Dryer $50.00 $699.00
MF G Energy Star Rated Front Load Washer $200.00 $3,074.00
MF G Smart Thermostat DIY with Natural Gas Heat $250.00 $368.76
Total $29,194.29 $133,633.03
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for Appliances Program in the section below.
3.2.1.1 Database Review& Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Appliance
Program.The Evaluators selected a random subset of rebate applications to cross-verify tracking data
inputs, summarized in Section 2.2.2.4.
The rebate application form aims to collect all required RTF measure specification details.The
Evaluators were able to verify the models for RTF specifications for most projects. One sampled gas
project did not include rebate data. Although model number is a required input, seven sampled gas
smart thermostat projects did not include this information in the rebate application and therefore did
not qualify for measure savings in accordance with the RTF. An additional five gas smart thermostat
projects included a model number that did not meet the RTF's efficiency standards. In total, 13 gas
projects with claimed savings failed to qualify for verified savings.
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3.2.1.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Appliances Program.The Evaluators
calculated verified savings for the gas measures using the RTF workbook in place at the time the savings
goals for the program were finalized. The Evaluators also conducted a billing analysis for all measures
with enough participation, however none of the gas measures in this program qualified for a billing
analysis and produced valid savings.
As discussed above, 13 sampled gas smart thermostat projects did not meet the minimum requirements
to qualify for RTF savings due to missing model numbers or a model that did not meet efficiency
standards,which contributed to the 73.70% realization rate. Additionally,verified savings resulted in a
realization rate less than 100% largely due to low savings attributed to the clothes dryer measure.The
RTF utilizes more inputs than the Avista TRM to estimate deemed savings, including home
characteristics like heat zone, heat type, water heat type, and efficiency tiers for dryers. After
accounting for these inputs,the magnitude of energy savings estimated by the TRM is only realized if
the measure qualifies for the RTF's highest tier of savings. For example, none of the sampled dryer
projects included models certified by the Northwestern Energy Efficiency Alliance (NEEA), leading to a
realization rate of 58.82%.
Interestingly, gas front load washer measures displayed realization rates above 100%.The Evaluators
note that the RTF applies specific savings depending on the customer's home heat type and hot water
heat type, and including those inputs in the Avista TRM could realize higher savings for the remaining
gas appliance measures than as currently evaluated.
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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 incentivizes ENERGY STAR' Eco-rated
homes.Table 3-7 summarizes the measures offered under this program.
Table 3-7:ENERGY STAR°Homes Program Measures
MethodologyMeasure Description Impact Analysis
G ENERGY STAR Home- ENERGY STAR-rated manufactured RTF UES
Manufactured,Gas Only home with natural gas
E ENERGY STAR Home-Manufactured, ENERGY STAR-rated manufactured RTF UES
Electric Only home with electric furnace
E ENERGY STAR Home-Manufactured, ENERGY STAR-rated manufactured RTF UES
Gas& Electric home with gas and electric
The following table summarizes the verified gas energy savings for the ENERGY STAR' Homes Program
impact evaluation.
Table 3-8:ENERGYSTAR°Homes Program Verified Gas Savings
Expected I Verified
Measure F�roject Savings Savings Realization
Cou nt (therms) (therms) Rate
G Energy Star Home-Manufactured,Gas 2 267.96 300.96 112.32%
Only
Total 2 267.96 300.96 112.32%
The ENERGY STAR® Homes Program displayed verified savings of 300.96 therms with a realization rate of
112.32% against the expected savings for the program. The following table summarizes the incentive
and measure costs associated with the program.
Table 3-9:ENERGY STAR°Homes Program Costs by Measure
I VIM
- .
ID-Gas Energy Star Home-Manufactured,
$1,200.00 $110,000.00
Gas Only
Toti al $1,200.00 $110,000.00
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.
3.2.2.1 Database Review& Document Verification
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 2.2.2.4.
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.
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3.2.2.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the ENERGY STAR' Homes Program.The
Evaluators calculated verified savings for the gas measures using the RTF workbook in place at the time
the savings goals for the program were 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. 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 112.32%with 300.96 therms
verified gas energy savings in the Idaho service territory, as displayed in Table 3-8.The realization rate
for the gas savings in the ENERGY STAR' Homes Program deviates from 100%due to the categorical
differences between the applied Avista TRM prescriptive savings value and the more detailed RTF UES
categories.
The realization rate for the G ENERGY STAR' Home—Manufactured, Gas Only measure is higher than
100% because the expected savings that were claimed do not take heating zones and cooling zones into
account.The Evaluators assigned gas savings from the RTF associated with the appropriate heating and
cooling zones rather than defaulting to an average value across all zones. Since the two gas
manufactured homes were installed in the RTF's Heating Zone 2 geography,the final verified gas savings
were higher than the expected values, which seem to be an average of Heating Zones 1 through 3. The
Evaluators recommend updating Avista measure savings to reflect heating zone-specific RTF measure
savings rather than averaging savings from heating zones together.
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3.2.3 Fuel Conversion Program
Avista's Residential Fuel Conversion 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 have
been at least 4,000 kWh during the prior year with less than 340 therms of natural gas use. Customers
receive incentives after installation and after submitting a completed rebate form. As detailed in the
following table,the Evaluators reference the Avista TRM to calculate the verified savings associated with
this program.This section outlines the increase in natural gas usage associated with participation in the
Fuel Conversion Program.
Table 3-10:Fuel Conversion Program Measures
MethodologyDescription Impact Analysis
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 gas energy savings for the Fuel Conversion Program impact
evaluation. Negative savings indicate that there was an increase in natural gas usage linked to
participation in this program.The reduction in electricity associated with this program is reported in the
Evaluators' Idaho Electric Portfolio Impact Evaluation Report.
Table 3-11:Fuel Conversion Program Verified Gas Savings
Expected Verified Realization
Project Count Savings Savings Rate
(therms) (therms)
E Electric to Natural Gas Furnace 7 -3,143.00 -3,143.00 100.00%
_E Electric to Natural Gas Furnace&Water Heat 4 -2,260.00 2,260.00 100.00%
Total 11 -5,403.00 -5,403.00 100.00%
The Fuel Conversion program displayed a verified increase in natural gas usage of at least-5,403.00
therms with a realization rate of 100.00%against the expected increase in therms calculated for the
program.The following table summarizes the incentive and measure costs associated with the program.
Of note, incentive and measure costs are applied to the Fuel Conversion Program section of the Idaho
Electric Portfolio Impact Evaluation Report, so to avoid double counting the Fuel Conversion costs in this
report are assumed to be zero.
Table 3-12: Fuel Conversion Program Costs by Measure
E Electric to Natural Gas Furnace $0.00 $0.00
E Electric to Natural Gas Furnace&Water Heat $0.00 $0.00
Total $0.00 7$0.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Fuel Conversion Program in the section below.
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3.2.3.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Fuel
Conversion Program.The Evaluators reviewed rebate applications for all 11 participants to cross-verify
tracking data inputs, summarized in Section 2.2.2.4.
The Evaluators found that all 11 sampled rebates accurately documented the information necessary to
characterize savings for the program within the Idaho gas service territory. The Evaluators verified the
installed gas equipment and other inputs necessary to calculate verified savings.The Evaluators'tracking
data review did not identify any duplicates in the tracking data.
3.2.3.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Fuel Conversion Program.The Evaluators
referenced the Avista TRM, as detailed above,to calculate verified savings associated with this program.
With a realization rate of 100.00%,verified electric savings matched expected savings. Of note,two of
the installed gas storage water heaters had a uniform energy factor(UEF) of 0.64 which was slightly
lower than the minimum required efficiency of 0.65 for storage water heaters. Given that the Avista
TRM does not include a savings value for 0.64 UEF storage water heaters specifically, the Evaluators
applied the gas penalty associated with the closest valid measure which yielded a 100% realization rate.
However, it is possible that the actual increase in gas usage may be slightly higher than reported due to
the slightly lower UEF value. Ultimately,the verified increase in gas usage associated with this program
very closely matched the expected values.
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Avista Idaho Gas PY2025 Qualus
3.2.4 Home Energy Audit Program
The Residential Home Energy Audit Program is designed to educate and generate interest in energy
efficiency and to motivate participation in Avista's portfolio of residential energy efficiency and
renewable-energy programs. As a part of this program, participating customers can conduct a DIY home
energy audit using a small thermal camera or a third-party contractor can visit and visually inspect the
customer's entire home to identify opportunities for energy savings.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 gas energy savings for the Home Energy Audit Program
impact evaluation.
Table 3-13:Home Energy Audit Program Verified Gas Savings
Project erified Realization
Count Savings Savings Rate
E(therms)T(Vtherms)
xpected
Home Energy Audit 190 NA 0.00 NA
Total 190 NA 0.00 NA
The Home Energy Audit Program displayed verified savings of 0.00 therms across 190 gas heating
households, due to the fact that gas billing analyses did not yield statistically significant savings
estimates.Avista did not estimate claimed savings for this program, and therefore no realization rate
was calculated. No cost information associated with the Home Energy Audit program was provided in
the tracking data shared with the Evaluators.
The Evaluators summarize the program-specific impact analysis activities, results, conclusions, and
recommendations for the Home Energy Audit Program in the section below.
3.2.4.1 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 Home Energy Audit Program tracking data in PY2025 and
identified participating customers with gas heating in the Idaho service territory.The Evaluators did not
identify any duplicates in the ID gas population tracking data.
3.2.4.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Home Energy Audit Program. The Evaluators
employed the following impact evaluation methodology to estimate verified net energy savings in the
Residential Home Energy Audit Program:
■ Billing Analysis with counterfactual group (IPMVP Option C)
In addition to motivating behavioral changes,the Home Energy Audit program can also provide direct
install measures to participating customers through Avista's residential energy efficiency programs.To
ensure these savings were not double counted,the Evaluators removed all customers participating in
other energy efficiency programs from the Home Energy Audit billing analysis cohort. After removing
these customers with potential for double counted savings from the analysis cohort,the Evaluators
conducted a billing analysis with a counterfactual group selected via propensity score matching.The
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Avista Idaho Gas PY2025 Qualus
methodology used to select the quasi-experimental counterfactual group and the methodology for
linear regression billing analysis are summarized in further detail in the Billing Analysis section above.
Table 3-14:Home Energy Audit Program
Treatment Customers Annual Savings Regression Estimate Program
Customers Included in per Customer Estimate p- Adjusted R- Verified Savings
Billing Analysis (therms) value squared (therms)
190 73 0.00 0.129 0.941 0.00
The evaluators ran separate billing analyses for each state and fuel type, meaning the savings results
presented in this report are specific to residential ID participants with gas heating. For the analysis of the
Home Energy Audit program,the Evaluators selected a Post-Program Regression (PPR) model as detailed
in the Model 2: Random Effects Post-Program Regression Model section above. This model did not yield
statistically significant savings, meaning savings of 0.00 therms were assigned to each participating
household.The evaluators provide additional information on billing analyses in the Appendix A: Billing
Analysis Results section below.
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3.2.5 Residential Midstream Program
Avista recently 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 tankless water heaters
Residential natural gas storage tank water heaters
Residential natural gas boilers
The residential midstream measures and impact evaluation results are presented in this section.This
change in delivery channel,from downstream to midstream, seems to have expanded the benefits
gained by Avista residential customers.
This section summarizes Avista's estimated savings for the Midstream Program as well as the verified
savings calculated by the Evaluators. Table 3-15 summarizes the measures offered under this program.
Table 3-15:Midstream Program Measures
MethodologyDescription impact Analysis
G Natural Gas Furnace High efficiency natural gas furnace
installation
G Natural Gas Boiler High efficiency natural gas boiler installation Avista TRM midstream
measure calculations
G Natural Gas Storage Tank Water High efficiency natural gas storage tank water that the Evaluators have
Heater heater installation reviewed
G Natural Gas Tankless Water High efficiency natural gas tankless water
Heater r heater installation
The following table summarizes the estimated gas energy savings for the Midstream Program impact
evaluation.
Table 3-16:Midstream Program Verified Gas Savings
Project Expected Verified Realization
Measure Count Savings Savings Rate
(Therms) (Therms)
G Natural Gas Boiler 16 1,610.11 1,610.75 100.04%
G Natural Gas Furnace 1,689 136,099.62 131,843.34 96.87%
G Natural Gas Storage Tank Water Heater 21 361.14 361.14 100.00%
G Natural Gas Tankless Water Heater 165 8,959.63 8,959.63 100.00%
Total 1,891 147,030.50 142,774.86 97.11%
The Midstream Program displayed estimated savings of 142,774.86 therms with a realization rate of
97.11%.The following table summarizes the incentive and measure costs associated with the program.
Given that measure costs were not included in Midstream tracking data, the Evaluators assumed
measure costs were identical to incentive costs.
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Avista Idaho Gas PY2025 Qualus
Table 3-17:Midstream Program Costs by Measure
N Dr. Incentive Costs Measure Costs
G Natural Gas Furnace $9,600.00 $9,600.00
G Natural Gas Boiler _ $705,250.00 $705,250.00
G Natural Gas Storage Tank Water Heater $2,625.00 $2,625.00
G Natural Gas Tankless Water Heater $20,625.00 $20,625.00
Total $738,100.00 $738,100.00
The Evaluators describe the impact evaluation tasks completed for this program in the subsections
below.
3.2.5.1 Database Review&Document 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 in
Section 2.2.2.4.
The Evaluators found all selected rebates documented the information necessary to accurately
characterize savings for the program within the Idaho gas service territory. The Evaluators verified the
model number, efficiency, quantity, and other information necessary to calculate verified savings.The
Midstream tracking data is tracked and delivered separately from the remaining residential portfolio,
often including extensive detail on product characteristics.
3.2.5.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Midstream Program.The Evaluators
reviewed and applied the appropriate Avista TRM values to assign verified savings to each of the
midstream measures. As highlighted in the Impact Evaluation Methodology section above, across 2024
and 2025 the Evaluators have collaborated with Avista to review and verify the methodologies used to
develop the midstream section of Avista's TRM.
The Evaluators reviewed the implementer expected savings values along with verified tracking data to
estimate net adjusted program savings for those measures. To calculate verified savings,the Evaluators
applied savings values from the Avista TRM that have been reviewed for accuracy by the Evaluators.The
Midstream Program displayed a 97.11% realization rate with 142,774.86 therms saved, as highlighted in
Table 3-16.The Evaluators concluded that the implementers correctly estimated expected savings
values and the deviations in realization rate were primarily due to minor differences in expected and
verified savings values for gas furnaces. Expected furnace savings of 80.58 therms were based on a
treatment-only billing data regression analysis run in July 2025 while verified furnace savings of 78.06
therms were based on a post-program regression (PPR) regression analysis run in March 2026.The
March 2026 PPR analysis followed the methodology outlined in the Model 2: Random Effects Post-
Program Regression Model section and was based on program participant and non-participant billing
data from 2023 through 2025.
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Avista Idaho Gas PY2025 Qualus
3.2.6 Residential Shell Program
The Residential Shell Program provides incentives to customers for improving the integrity of their
home's envelope with upgrades to weatherization measures. Rebates are issued after the measure has
been installed for insulation and window measures. Participating homes must have electric 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 gas usage of at least 340 therms. Primary multifamily homes with
shared interior walls including apartments, duplexes, townhomes, and condos have no minimum usage
requirement. Seasonal and recreational homes are not eligible. This program includes free
manufactured home duct sealing. Table 3-18 summarizes the measures offered under this program.
Table 3-18:Shell Program Measures Impact
MethodologyMeasure Description Analysis
G Attic Insulation With Natural Gas Heat Attic insulation for homes heated with natural gas RTF UES
G Energy Star Certified Insulated Door Replace door with ENERGY STAR rated door in homes RTF UES
heated with natural gas
G Floor Insulation With Natural Gas Heat Floor insulation for homes heated with natural gas RTF UES
G Sliding Glass Doors DIY with Natural Gas High efficiency sliding glass door replacement for
Heat homes heated with natural gas installed by RTF UES
homeowner
G Sliding Glass Doors with Natural Gas Heat High efficiency sliding glass door replacement for RTF UES
homes heated with natural gas installed by contractor
G Storm Window DIY with Natural Gas Heat High-efficiency storm window replacement for homes RTF UES
heated with natural gas installed by homeowner
High-efficiency storm window replacement for homes
G Storm Window with Natural Gas Heat RTF UES
heated with natural gas installed by contractor
G Wall Insulation With Natural Gas Heat Wall insulation for homes heated with natural gas RTF UES
High-efficiency double pane window replacement for
G Window DIY Replc With Natural Gas Heat homes heated with natural gas installed by RTF UES
homeowner
G Window Replc With Natural Gas Heat High-efficiency double pane window replacement for RTF UES
homes heated with natural gas installed by contractor
Multifamily G Attic Insulation With Natural Attic insulation for homes heated with natural gas RTF UES
Gas Heat
Multifamily G Energy Star Certified Insulated Replace door with ENERGY STAR rated door in homes RTF UES
Door heated with natural gas
Multifamily G Floor Insulation With Natural Floor insulation for homes heated with natural gas RTF UES
Gas Heat installed by contractor
Multifamily G Sliding Glass Doors with High efficiency sliding glass door replacement for RTF UES
Natural Gas Heat homes heated with natural gas
Multifamily G Window DIY Replc With High-efficiency double pane window replacement for
Natural Gas Heat homes heated with natural gas installed by RTF UES
homeowner
Multifamily G Window Replc With Natural High-efficiency double pane window replacement for RTF UES
Gas Heat homes heated with natural gas installed by contractor
The following table summarizes the verified gas energy savings for the Shell Program impact evaluation.
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Table 3-19:Shell Program Verified Gas Savings
Project Expected Verified Realizatio
Measure Count Savings Savings n Rate
(therms) (therms)
G Attic Insulation With Natural Gas Heat 25 1,853.46 2,044.74 110.32%
G Energy Star Certified Insulated Door 49 1,634.50 180.16 11.02%
G Floor Insulation With Natural Gas Heat 8 157.24 489.63 311.40%
G Sliding Glass Doors DIY with Natural Gas Heat 5 83.50 70.71 84.68%
G Sliding Glass Doors with Natural Gas Heat 135 2,972.60 2,389.20 80.37%
G Wall Insulation With Natural Gas Heat 6 295.45 438.56 148.44%
G Window DIY Replc With Natural Gas Heat 19 590.30 277.35 46.98%
G Window Replc With Natural Gas Heat 373 18,277.00 15,080.05 82.51%
Multifamily G Attic Insulation With Natural Gas Heat 1 80.34 88.63 110.32%
Multifamily G Energy Star Certified Insulated Door 1 3.40 0.37 11.02%
Multifamily G Floor Insulation With Natural Gas Heat 1 17.60 54.81 311.40%
Multifamily G Sliding Glass Doors with Natural Gas Heat 2 33.40 26.84 80.37%
Multifamily G Window DIY Replc With Natural Gas Heat 1 37.80 17.76 46.98%
Multifamily G Window Replc With Natural Gas Heat 5 60.78 50.15 82.51%
Total 631 26,097.37 21,208.97 81.27%
The Shell Program displayed verified savings of 21,208.97 therms with a realization rate of 81.27%
against the expected savings for the program.The following table summarizes the incentive and
measure costs associated with the program.
Table 3-20:Shell Program Costs by Measure
Measure Incentive Costs Measure Costs
G Attic Insulation With Natural Gas Heat $20,722.88 $76,324.61
G Energy Star Certified Insulated Door $6,600.00 $177,096.47
G Floor Insulation With Natural Gas Heat $5,896.36 $18,023.84
G Sliding Glass Doors DIY with Natural Gas Heat $1,260.00 $6,457.33
G Sliding Glass Doors with Natural Gas Heat $87,120.00 $881,568.96
G Wall Insulation With Natural Gas Heat $4,431.75 $9,425.94
G Window DIY Replc With Natural Gas Heat $6,358.00 $49,459.56
G Window Replc With Natural Gas Heat $299,837.00 $4,999,067.60
Multifamily G Attic Insulation With Natural Gas Heat $2,008.50 $5,146.00
Multifamily G Energy Star Certified Insulated Door $100.00 $1,868.28
Multifamily G Floor Insulation With Natural Gas Heat $132.00 $6,450.00
Multifamily G Sliding Glass Doors with Natural Gas Heat $960.00 $3,911.75
Multifamily G Window DIY Replc With Natural Gas Heat $540.00 $2,862.83
Multifamily G Window Replc With Natural Gas Heat $3,465.00 $56,041.48
Total $439,431.49 $6,293,704.65
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Shell Program in the section below.
3.2.6.1 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 2.2.2.4.
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Avista Idaho Gas PY2025 Qualus
The Evaluators reviewed each measure's number of units, square footage, and insulation where
available. Not all rebated projects provided sufficient documentation to verify each of the specifications
that the Evaluators reviewed such as square footage quantities for windows and sliding glass doors.
When square footage was not provided,the Evaluators imputed a square footage of 20 square feet per
window and 40 square feet per sliding glass door to apply RTF savings at the square footage level so that
RTF deemed savings could be applied."'
The Evaluators found that verified attic insulation, certified insulated doors, and some window measure
savings were lower than expected primarily due to differences in the Avista TRM's application of
deemed savings and the RTF UES workbook application of deemed savings. In most cases Avista applies
a single savings value to each installed measure regardless of customer location or heating equipment
type. In contrast, the RTF differentiates savings by square footage, heating type, R-values (for insulation
measures), U-factors (for window measures), and climate zone.The lack of granularity in the Avista TRM
data led to a low realization rate for many measures.
3.2.6.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Shell Program.The Evaluators calculated
verified savings for the gas measures using the RTF workbook in place at the time the savings goals for
the program were finalized.The Evaluators calculated adjusted savings for each measure using the
active Avista TRM values and verified tracking data.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.
The Shell Program in total displays a realization rate of 81.27%with 21,208.97 therms verified gas
energy savings in the Idaho service territory, as displayed in Table 3-19.
Realization rates deviate from 100% largely due to two factors. First,there is a significant difference in
the methods applied by the Avista TRM and the RTF for efficient window, insulated door, and sliding
glass door measures.The RTF's deemed savings are estimated at the square-foot unit level, whereas the
Avista TRM estimates savings per window or door.This causes significant variance between the two
estimates when the unit-energy-savings are scaled by two different quantities. It follows that measures
with smaller sample sizes are more vulnerable to this variance, as demonstrated by the low realization
rate for the G Sliding Glass Doors DIY with Natural Gas Heat measure. In addition, in the case of
insulated doors,the Avista TRM assumed doors yielded savings of 27.3 therms per door while the RTF
assigns savings between 0.17 and 0.20 therms per square foot of insulated door. Most sampled doors
had relatively small square footage which yielded substantially lower overall verified savings than
Avista's ex-ante estimates.
Second, Attic insulation, wall insulation, and floor insulation measures are evaluated at different
efficiency tiers depending on the R-value of the pre-existing and newly installed insulation. Many of
9 Square footage estimate for residential windows are drawn from a Pacific Northwest National Laboratory analysis found here:
https://www.pnnl.gov/main/publications/external/technical_reports/PN N L-28809.pdf
io Square footage estimate for residential sliding glass doors are drawn from the RTF's SEEM model found here:
https://nwcounciI.app.box.com/s/oIba73ckvxplogpgO24gclydzz38i3xv
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Avista Idaho Gas PY2025 Qualus
these insulation projects display high realization rates because the expected savings were lower than
the verified RTF savings associated with the specific change in R-value of the sampled projects. For
example,the Avista TRM seems to apply savings of 0.08 therms per square foot of attic insulation while
the RTF deemed savings values applied to sampled projects ranged between 0.08 and 0.30 therms per
square foot. Similarly, the Avista TRM seems to apply savings of 0.02 therms per square foot and 0.05
therms per square foot for floor and wall insulation, respectively. In contrast, sampled projects had RTF
deemed savings estimates of 0.11 therms per square foot and 0.20 therms per square foot for those
same two measures. Differentiating insulation measure expected savings by installed R-value and
customer location would help Avista's ex-ante estimates align more closely to verified savings estimates
in the future.
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Avista Idaho Gas PY2025 Qualus
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 serve
households based on a variety of 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.
During PY2025,the Evaluators completed impact evaluations on Avista's Low-Income Program for both
the 2024 and 2025 program years.The following sections summarize findings for each gas impact
evaluation in the Low-Income Portfolio in the Idaho service territory.
The Evaluators used data collected and reported in the tracking database, online application forms, and
RTF values to evaluate verified 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 4-1 summarizes the Low Income expected and verified
impact savings by program year.
Table 4-1:Low Income Verified Impact Savings by Program Year
Program Program Project Count Expected Savings Verified Savings Realization Rate
Year (therms) (therms)
2024 Low Income 39 1,380.11 1,283.79 93.02%
2025 Low Income 134 3,866.78 3,832.95 99.13%
Total 173 5,246.89 5,116.74 97.52%
The Idaho Low Income gas program yielded verified savings of 1,283.79 therms in 2024 and 3,823.95
therms in 2025 for realization rates of 93.02%and 99.13%, respectively.The following table presents
low-income incentive and measures costs by program.
Table 4-2:Low Income Costs by Program Year
Program Year Program Incentive Costs Measure Costs
2024 1 Low Income 186,029.73 167,212.75
2025 1 Low Income 476,683.88 415,308.52
Total 662,713.61 582,521.27
4.1 Simple Verification Results
Details on the simple verification conducted for the Low Income program are presented below.
4.1.1 In-Service Rates
The Evaluator conducted a simple participant verification survey for the Low Income Program to
calculate in-services rates of installed measures. Due to the limited number of completed surveys (n =
14), responses from both states were aggregated to increase the stability of the verification estimate.
Based on this combined dataset,the Evaluators calculated an overall installation verification rate of
93%.
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Non-verification responses were concentrated among measures such as air sealing and insulation, which
are typically not visible to participants and therefore susceptible to recall error and limited participant
awareness of work performed by contractors. Because all Low Income measures are installed through
program-delivered services rather than customer-directed installations,the likelihood of true non-
installation was assessed to be low. In this context,the observed non-verification is more plausibly
attributed to survey measurement error rather than actual deviations from installation requirements.
Given the small sample size, the nature of the measures involved, and the controlled contractor delivery
model, the evaluation team determined that the most technically appropriate approach was to treat all
Low Income Program measures as fully installed, applying a 100% ISR for the PY2024 and PY2025
evaluation.The survey-derived rate is noted for transparency, but it is not used to downward-adjust
measure savings due to the limitations described above.
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4.2 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.
4.2.1 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.Table 4-3 summarizes the measures offered under this
program.
Table 4-3: Low Income Program Measures
MethodologyMeasur'L. Impact Analysis
G 50 Gallon Natural Gas Water Heater
G Air Infiltration
G Attic Insulation With Natural Gas Heat
G Duct Insulation
G Duct Sealing
G Exterior Doors
G Floor Insulation With Natural Gas Heat
RTF UES
G Health Safety and Repair
G Natural Gas Furnace
G Smart Thermostat
G Storm Windows
G Tankless Water Heater
G Wall Insulation With Natural Gas Heat
G Window Replacement With Natural Gas Heat
Table 4-4 summarizes the PY2024 verified gas energy savings for the Low Income Program impact
evaluation.
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Table 4-4:PY2024 Low Income Program Claimed Gas Savings
Expected Verified Realization
Measure Project Count Savings Savings Rate
(therms) (therms)
G Air Infiltration 2 24.46 15.63 63.89%
G Attic Insulation With Natural Gas Heat 2 210.60 181.08 85.98%
G Duct Insulation 1 7.00 8.82 125.96%
G Duct Sealing 2 40.34 78.00 193.36%
G Exterior Doors 2 19.32 8.08 41.85%
G Floor Insulation With Natural Gas Heat 1 78.68 51.40 65.33%
G Natural Gas Furnace 14 871.36 735.03 84.35%
G Health Safety and Repair 9 0.00 0.00 N/A
G Tankless Water Heater 1 66.50 60.69 91.27%
G 50 Gallon Natural Gas Water Heater 2 14.10 0.00 0.00%
G Window Replacement With Natural Gas Heat 3 47.75 145.06 303.78%
Total 39 1,380.11 1,283.79 93.02%
The Low Income Program displayed verified savings of 1,283.79 therms for the 2024 program with a
realization rate of 93.02%.The following table summarizes the incentive and measure costs associated
with the program in PY2024.
Table 4-5:PY2024 Low Income Program Claimed Costs by Measure
G Air Infiltration $168.92 $3,303.31
G Attic Insulation With Natural Gas Heat $3,363.75 $3,135.30
G Duct Insulation $110.40 $96.00
G Duct Sealing $271.00 $235.65
G Exterior Doors $1,355.00 $1,178.26
G Floor Insulation With Natural Gas Heat $1,253.82 $3,171.34
G Natural Gas Furnace $106,501.09 $92,609.64
G Health Safety and Repair $55,332.25 $48,114.99
G Tankless Water Heater $4,188.30 $3,642.00
G 50 Gallon Natural Gas Water Heater $8,367.15 $7,275.78
G Window Replacement With Natural Gas Heat $5,118.05 $4,450.48
Total $186,029.73 $167,212.75
Total without Health Safety and Repair $130,697.48 $119,097.76
Table 4-6 summarizes the PY2025 verified gas energy savings for the Low Income Program impact
evaluation.
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Table 4-6:PY2025 Low Income Program Claimed Gas Savings
Project Expected Verified Realization E
Measure Count Savings Savings Rate
(therms) (therms)
G Air Infiltration 13 158.99 101.57 63.89%
G Attic Insulation With Natural Gas Heat 4 414.54 356.43 85.98%
G Duct Insulation 5 49.00 61.72 125.96%
G Duct Sealing 2 40.34 78.00 193.36%
G Exterior Doors 8 96.60 40.42 41.85%
G Floor Insulation With Natural Gas Heat 3 215.74 140.95 65.33%
G Natural Gas Furnace 34 2,116.16 1,785.07 84.35%
G Health Safety and Repair 29 0.00 0.00 N/A
G Tankless Water Heater 4 266.00 242.77 91.27%
G Wall Insulation With Natural Gas Heat 1 58.86 0.00 0.00%
G 50 Gallon Natural Gas Water Heater 16 112.80 0.00 0.00%
G Window Replacement With Natural Gas Heat 15 337.75 1,026.02 303.78%
Total 134 3,866.78 3,832.95 99.13%
The Low Income Program displayed verified savings of 3,832.95 therms for the 2025 program with a
realization rate of 99.13%.The following table summarizes the incentive and measure costs associated
with the 2025 program year.
Table 4-7:PY2025 Low Income Program Claimed Costs by Measure
a 0- �, Incentive Costs Measure Costs—
G Air Infiltration $1,097.98 $1,354.32
G Attic Insulation With Natural Gas Heat $6,132.33 $5,332.46
G Duct Insulation $772.80 $672.00
G Duct Sealing $362.98 $716.88
G Exterior Doors $6,103.00 $5,306.96
G Floor Insulation With Natural Gas Heat $3,437.97 $2,989.54
G Natural Gas Furnace $232,046.93 $201,779.94
G Health Safety and Repair $102,283.29 $88,941.99
G Tankless Water Heater $21,010.96 $18,270.40
G Wall Insulation With Natural Gas Heat $846.11 $735.75
G 50 Gallon Natural Gas Water Heater $55,618.14 $48,363.60
G Window Replacement With Natural Gas Heat $46,971.39 $40,844.68
Total $476,683.88 $415,308.52
Total without Health Safety and Repair $374,400.59 $326,366.53
4.2.1.1 Database Review& Document Verification
Before conducting the impact analysis,the Evaluators performed a comprehensive review of the Low
Income Program tracking database to assess data completeness, accuracy, and consistency. As part of
this process,the Evaluators selected a random subset of rebate applications to cross-verify tracking
system inputs with submitted project documentation, as summarized in Section 2.2.2.4.
The Evaluators found no duplicate participants in the project data and found that program data
appropriately reflected customer rate information.
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4.2.1.2 Impact Analysis Savings Verification Findings
This section summarizes the verified savings results for the Low Income Program for PY2024 and
PY2025.The Evaluators calculated verified savings for the gas measures using the RTF workbook in place
at the time the savings goals for the program were 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.
The Low Income Program displayed the following savings and realization rates for each project year:
■ PY2024: 1,283.79 therms, 93.02% RR
■ PY2025: 3,832.95 therms, 99.13% RR
Measure details can be found in Table 4-4 and Table 4-6.
Potential causes of discrepancies between reported and verified savings for the Low Income Program
are outlined in the sections below.
Measure Quantity Field Inconsistencies
The measure quantity field in the tracking data was populated inconsistently across measure types. For
example, for insulation measures,the quantity represented square footage installed,whereas for other
measures, such as furnaces or smart thermostats,the field represented count of units or projects
installed.
To support future evaluations and ensure data clarity,the Evaluators recommend that the tracking
system include separate, measure-specific data fields (e.g., "Installed Area (sq ft)," "Quantity Installed,"
"Units per Project")to reduce ambiguity and improve data usability.
Manufactured and Multifamily Home Treatment
In cases where RTF savings methodologies do not provide measure-specific savings values for
Manufactured or Multifamily homes,the Evaluators applied Single Family savings values.
Exterior Door Assumptions
The tracking database did not include the square footage of replacement exterior doors. To complete
the savings calculations,the Evaluators assumed an average replacement door area of 20 square feet
per project, based on typical residential door dimensions.
Storage Tank Water Heater Savings
RTF guidelines require that storage tank water heaters be ENERGY STAR certified in order to claim
savings. During the sample review, all three sampled projects were found to have installed a
non-ENERGY STAR unit. Because the equipment did not meet RTF eligibility requirements, these projects
did not yield savings leading to zero savings being applied to the population of storage water heaters.
Window Measure Data Gaps
RTF savings methodologies for windows require identification of installed window type. Because the
tracking data only listed the pre-existing window type,the Evaluators applied a conservative assumption
framework when assigning savings.
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Avista Idaho Gas PY2025 Qualus
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 PY2025.The following sections summarize findings for each
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, RTF, IPMVP-
approved analyses, and supplemental sources 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
Program Project Count Expected Savings Verified Savings 1 Realization
I (therms) (therms) Rate
Non Residential Midstream 79 28,201.96 28,136.73 99.77%
Non Residential Shell 2 628.42 168.53 26.82%
Site Specific-Other 2 3,003.00 2,838.00 94.51%
Total 83 31,833.38 31,143.27 97.83%
Non Residential program incentive and measure costs are presented in the following table. Measure
costs were not presented in the Non Residential midstream program tracking data and as such they
were assumed to be identical to incentive costs.
Table 5-2:Non Residential Costs by Program
Program Incentive Costs Measure Costs
Non Residential Midstream $106,564.00 $106,564.00
Non Residential Shell $5,909.12 $7,400.00
Site Specific-Other $10,508.75 $127,565.51
Total $122,981.87 $241,529.51
In PY2025, verified energy savings of 31,143.27 therms were identified for Avista's non-residential gas
measures in Idaho.All programs except for the Non Residential Shell program had realization rates
between 95%and 100%.The Non Residential Shell program meanwhile had savings of 26.82% based on
engineering equation calculations. Across all Non Residential programs the Evaluators calculated a
97.83% realization rate.
5.1 Database & Document Verification
Before conducting the impact analyses,the Evaluators conducted a database review for all prescriptive
programs.This process began with the selection of representative samples from each program. The
Evaluators developed a sampling plan that achieves a sampling precision of±10% at 90%statistical
confidence—or"90/10 precision"—for document verification. Details about sampling methods can be
found in 2.2.1 Database Review and details about the verification process can be found in Section
2.2.2.4.The Evaluators reviewed both tracking data and additional documentation materials to identify
any typos, duplicates, or other data concerns that might affect the verified savings analysis. Information
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Avista Idaho Gas PY2025 Qualus
on the sample sizes reviewed as a part of the database and document verification process can be found
in the Sampling Methodology for Most Programs section above.
The Evaluators did not conduct survey verification for Idaho non-residential gas measures as a part of
the process evaluation. Instead, the Evaluators relied on database and documentation verification and
applied 100% in-service rates to non-residential gas measures.
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5.2 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.
5.2.1 Non Residential 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, 2024,
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 non-residential
customers.This chapter discusses and presents results only for non-residential measures.Table 5-3
summarizes the measures available to be rebated in PY2025 under this program.
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Table 5-3:Non Residential Midstream Program Measures
MethodologyEnd Use Measure Impact Analysis
Combination Oven Avista TRM (per RTF Combination Ovens)
Convection Oven Avista TRM (per RTF Convection Ovens)
Demand Control Kitchen Ventilation Avista TRM
Dishwasher Avista TRM (per ENERGY STAR CFS Calculator)
Fryer Avista TRM
Food Service Griddle Avista TRM (per RTF Griddles)
Hot Food Holding Bin Avista TRM (per CA eTRM HFHB)
Hot Food Holding Cabinet RTF HFHC
Ice Machine Avista TRM (per RTF Ice Machines)
Rotisserie Oven Avista TRM (per CA eTRM Rotisserie Ovens)
Steamer Avista TRM (per RTF Steamers)
Boiler Avista TRM (per RTF Commercial Boilers)
Furnace Avista TRM (per billing analysis)
HVAC Mini/Multi Split Avista TRM (per engineering algorithm)
Packaged Unitary Equipment Avista TRM (per engineering algorithm)
Split Unitary Equipment Avista TRM (per engineering algorithm)
Water Source Heat Pump Avista TRM (per engineering algorithm)
Heat Pump Water Heater Avista TRM (per RTF HPWH)
Water Heating Instantaneous Water Heater Avista TRM (per RTF Gas Water Heaters)
Storage Water Heater Avista TRM (per RTF Gas Water Heaters)
Other Ultra-Low Temperature Freezer Avista TRM (per CA eTRM Ultra Low Temp
Freezers)
The following table summarizes the verified gas energy savings for the Midstream Program impact
evaluation.
Table 5-4:Non Residential Midstream Program Verified Gas Savings
Measure Project Expected Savings Verified Savings Realization Rate
Count (therms) (therms)
Boiler 3 6,318.56 6,318.56 100.00%
Fryer 3 2,443.00 2,443.00 100.00%
Furnace 52 5,885.13 5,885.13 100.00%
Instantaneous Water Heater 3 787.51 722.29 91.72%
Storage Water Heater 18 12,767.75 12,767.75 100.00%
Total 79 28,201.96 28,136.73 99.77%
The following table summarizes the incentive and measure costs associated with the program. Of note,
no complete measure cost information outside of incentive costs was included in the tracking data
provided, and as such the Evaluators have assumed incentive costs are identical to overall measure
costs.
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Avista Idaho Gas PY2025 Qualus
Table 5-5:Non Residential Midstream Program Costs by Measure
Measure Measure Unit Incentive Costs Measure Costs
Count
Boiler 4.00 $27,000.00 $27,000.00
Fryer 7.00 $7,350.00 $7,350.00
Furnace 55.00 $35,500.00 $35,500.00
Instantaneous Water Heater 3.00 $1,791.00 $1,791.00
Storage Water Heater 24.00 $34,923.00 $34,923.00
Total 93.00 $106,564.00 $106,564.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Midstream Program in the section below.
5.2.1.1 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.The Evaluators found all rebate
equipment met or exceeded the measure efficiency requirements for the Midstream Program and
minimal equipment specifications differed from those in the tracking data. Furthermore, no duplicates
were identified in the tracking data.
5.2.1.2 Impact Analysis
Once verification was completed, to estimate program savings for these measures the Evaluators
reviewed and applied the appropriate Avista TRM values to assign verified savings to each of the
midstream measures. As highlighted in the Impact Evaluation Methodology section above, across 2024
and 2025 the Evaluators have collaborated with Avista to review and verify the methodologies used to
develop the midstream section of Avista's TRM. For measures not included in the TRM, the Evaluators
referenced a relevant RTF workbook to identify appropriate verified savings values. Savings values are
specific to installed equipment efficiency and configuration.
5.2.1.3 Verified Savings
The verified savings for the program are 28,136.73 therms with a realization rate of 99.77%.All
measures except for instantaneous water heaters had realization rates of 100%, suggesting excellence
consistency in ex-ante and ex-post savings methodologies. Below,the Evaluators discuss the
instantaneous water heater measure:
■ Instantaneous Water Heaters:Two of the three sampled instantaneous water heaters had a
uniform energy factor (UEF) of 0.93, per model specifications,while expected savings
calculations seemed to have assumed a UEF of 0.95.This difference in UEF contributed to the
91.72% realization rate for the measure.
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Avista Idaho Gas PY2025 Qualus
5.2.2 Non Residential Shell Program
The Non Residential Non Residential 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 5-6 summarizes the measures rebated in PY2025 under this program.
Table 5-6:Non Residential Shell Program Measures
MethodologyImpact Analysis
Attic Insulation Illinois TRM v12.0 Section 4.8.2
The following table summarizes the verified gas energy savings for the Non Residential Shell Program
impact evaluation.
Table 5-7: Non Residential Shell Program Verified Gas Savings
Measure Count Savings Savings Rate
(therms) (therms)
Attic<_ R11 to R45+ 2 628.42 168.53 __7"26.82%
Total 2 628.42 168.53 26.82%
The following table summarizes the incentive and non-incentive costs associated with the program.
Table 5-8:Non Residential Shell Program Costs by Measure
Measure Square Footage Incentive Costs Measure Costs
Installed
Attic<_R11 to R45+ 5,234.00 $5,909.12 $7,400.00
Total 5,234.00 1 $5,909.12 $7,400.00
The Evaluators summarize the program-specific and measure-specific impact analysis activities, results,
conclusions, and recommendations for the Non Residential Shell Program in the section below.
5.2.2.1 Database Review&Document Verification
Before conducting the impact analysis,the Evaluators conducted a database review for the Non
Residential Shell Program.The Evaluators review all rebate applications to cross-verify tracking data
inputs, summarized in Section 2. 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 5-9 shows the project population,the number of projects checked and the overall
precision.
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Avista Idaho Gas PY2025 Qualus
Table 5-9: Non Residential Shell Program Verification Precision
2 2 0.0%
All gas projects provided in the program tracking data matched data verified in the rebate application,
and no adjustments to any savings algorithm inputs were necessary. The Evaluators found all rebate
equipment met or exceeded the measure efficiency requirements for the Non Residential Shell Program.
5.2.2.2 Impact Analysis
This section summarizes the verified savings results for the Non Residential Shell Program.The
Evaluators calculated verified savings for the insulation measures using the Illinois TRM v12.0 Section
4.8.211.The Illinois TRM was selected because it provides engineering algorithms to calculate savings for
commercial roof insulation and commercial wall insulation measures.To estimate savings for attic
insulation measures,the Evaluators applied the algorithm for commercial roof insulation.
The savings algorithms for attic insulation required weather inputs and HVAC equivalent full load hours
for various building types.The Evaluators calculated weather inputs in accordance with the Illinois TRM
for weather stations in Sandpoint, ID. Equivalent full load heating hours by building type were drawn
from Idaho Power TRM v3.212.
Illinois TRM v12.0 Section 4.8.2 provides the following equation to estimate roof insulation savings:
1 1 Area X EFLHheating X ATFL,heating
Therms = —— —(Rexisting A X 100,000 X Llheating
Where:
■ Rexisting = R-value of the existing insulation
■ RneW = R-value of the installed insulation
■ Area = Surface Area of the insulated roof in square feet
■ EFLHheating = Equivalent Full Load Cooling Hours in the Building
0 ATFL,heating =Temperature difference during heating season using a 55' F temperature setpoint
■ 100,000 = Conversion from BTUs to Therms
■ 77heating = Efficiency of existing furnace, assumed to be 0.78
5.2.2.3 Verified Savings
The verified savings for the program are 168.53 therms with a realization rate of 26.82%, as displayed in
Table 5-7. Avista's expected savings seem to have been calculated using a different methodology than
the Evaluators. Avista's methodology seems to assume substantially higher gas savings for attic
insulation. In addition,the Evaluators calculated gas savings using an engineering equation with weather
inputs specific to Sandpoint, ID.The integration of actual 2025 weather data into the verified analysis
likely contributed to lower savings values than generalized estimates used by Avista for expected
savings.
11 https://www.ilsag.info/wp-content/uploads/IL-TRM-Version-12.0-Volumes-1-4-Compiled-Final.pdf
12 https:Hdocs.idahopower.com/pdfs/EnergyEfficiency/Reports/2020TRM.pdf
Impact Evaluation Report 55

Avista Idaho Gas PY2025 Qualus
5.2.3 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 gas offerings.The program
approach strives for a flexible response to energy efficiency projects that have demonstrable therms
savings within program criteria.The majority of site-specific therms 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 gas customers
and typically brings in the largest portion of savings to the overall energy efficiency portfolio.
The following table summarizes the verified gas energy savings for the Site-Specific Program impact
evaluation.
Table 5-10:Site-Specific Program Verified Gas Savings
Project Expected Verified Realization
Type of Project
(therms) (therms)
Non-Lighting 2 1 3,003.00 1 2,838.00 1 94.51% 1
Total 2 3,003.00 2,838.00 94.51%
The Site-Specific Program displayed verified savings of 2,838.00 therms with a realization rate of 94.51%
against the expected savings for the program.
Table 5-11:Site-Specific Program Costs
Type of Project Incentive Costs Measure Costs
Non-Lighting $10,508.75 $127,565.51
Total $10,508.75 $127.565.51
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.
5.2.3.1 Sample Design
In the Site Specific PY2025 evaluation, the Evaluators sampled and reviewed the full population of Idaho
gas programs. As such, no sample design was required as all programs were reviewed and analyzed for
savings.This means that this evaluation had a 0.00% precision at 90%confidence (well below the
industry-standard 90/10 precision goal).
5.2.3.2 Project Document Review
Once representative projects were selected,the Evaluators obtained all project-related documentation
for review.These documents typically included equipment specification 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
Impact Evaluation Report 56

Avista Idaho Gas PY2025 Qualus
collecting on-site data. Using project-specific M&V plans,the Evaluators visited sampled to verify
measure installation and operating parameters, as well as building parameters such as square footage
and HVAC configurations.
5.2.3.3 Impact Approaches
The Evaluators employed IPMVP Option A-C approaches to calculated verified savings associated with
the Site Specific programs. Evaluators selected the most appropriate IPMVP-approved methodology
based on available data,the percentage of facility savings associated with the installed measure, and the
complexity of the energy efficiency equipment installed.
5.2.3.4 Site-Level Realization
Verified savings were developed for each sampled site.The realization rates for sites within each
stratum are normally applied to the non-sampled sites within their respective stratum but the sample
population included all Idaho Gas projects and as a result all site analysis are shown below.
Table 5-12:Site-Specific Expected,Adjusted and Verified therms Savings by Project
Project ID Expected therms Verified therms Realization Rate
Savings Savings
SSOP_136051 2,607.00 2,615.00 100.31%
SSOP 157240 396.00 223.00 56.31%
Totals: 3,003.00 2,838.00 94.51%
The overall PY2025 Site-Specific Program in total displays a total of 2,838.00 therms verified gas energy
savings in the Idaho service territory, as displayed in Table 5-12.
5.2.3.5 Discussion of Non-100%Realization in Sampled Projects
Below are brief explanations of differences between claimed and verified savings for projects with
realization rates that are not 100%.
■ SSOP_157240—The energy savings calculation information provided utilized an engineering
methodology that could not be reversed engineered with the given documentation. Initially, the
Evaluators proceeded to conduct a billing analysis utilizing the available site billing data.The
billing data provided only covered a few months of the reporting period, resulting in a poor
predictive model.Therefore, a deemed value of 0.62 therms per square foot of window from
the Idaho TRM 0.2 for Efficient Windows was applied to calculate savings. This model yielded a
realization rate of 56.31%for therms consumption.
■ SSOP_136051—The energy savings calculation information provided utilized an engineering
methodology that could not be reversed engineered with the given documentation.Therefore,
the Evaluators proceeded to conduct a billing analysis utilizing the available site billing data.This
model yielded a realization rate of 100.31%for therms consumption.
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Avista Idaho Gas PY2025 Qualus
6. Appendices
6.1 Appendix A: Billing Analysis Results
This appendix provides additional details on the billing analyses conducted for each program. 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). Analyses were run focusing specifically on the Idaho service
territory.The billing analysis on individual measures resulted in statistically significant gas impacts for
the natural gas furnace measure that is currently implemented as a part of the Residential Midstream
Program.The following section describes the analysis.
6.1.1 Natural Gas Furnace
The results of the billing analysis for the natural gas furnace measure are provided below.The
Evaluators identified 1001 customers who had only installed gas furnace energy efficiency measures
between 2023 and April 1, 2025 and included these customers in a treatment cohort to identify the
natural gas savings associated with furnace installation in Avista's Idaho service territory.
The Evaluators were successful in creating a matched cohort for the furnace measure with sufficient
participation. Customers were matched on zip code 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.The Evaluators conducted
propensity score matching(PSM) with replacement to match treatment customers to non-participant
control customers to develop cohorts with statistically similar pre-period energy usage.
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. After PSM,t-tests displayed no more
than 2 months with significantly different energy usage at the 95%alpha indicating treatment and
control pre-period energy usage were statistically similar.
The table below provides annual savings per customer and verified program savings for the Home
Energy Audit Program for the PPR model. Treatment customers included in the billing analysis
participated in this measure only, and therefore no double-counted savings from other programs need
to be accounted for.The total measure savings was thus verified to be 78,138.06 therms saved annually
for treatment customers specifically included in the regression analysis, or 10.59%of annual gas
household consumption.
Table 6-1:Regression Savings, Natural Gas Furnace
ModelAnnual Savings Treatment Program Regression Adjusted R-
(therms) (therms) value
78.06 1,001 78,138.06 <0.000 0.876 PPR
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Avista Idaho Gas PY2025 Qualus
6.2 Appendix B: Site Specific M&V Plans
6.2.1 Site Specific M&V Plans
6.2.1.1 SSOP 136051 Schweitzer Mt Residential
Summary
This facility is a ski resort residential lodging that performed a snow melt boiler retrofit.
Special On-Site Equipment
Camera
Data Collection
■ Verify installation of new equipment.
■ Verify efficiency of the new equipment.
■ Collect natural gas billing data.
o June 2023 to May 2024 for the baseline period.
o June 2024 and on for the performance period.
EEM Verification
Number of Name Efficiency
Units
3 Lochinvar 399 kBtu 95%
Boilers
Impact Evaluation Report 59

Appendix C: 2025 Cost-Effectiveness Tables

Electric Portfolio
st-Effectiveness Test Benefits Costs Benefit/Cost
Ratio
Total Resource Cost(TRC) $26,734,655 $23,820,458 1.12
Utility Cost Test(UCT) $26,734,655 $19,039,212 1.40
Participant Cost Test(PCT) $42,092,287 $20,138,877 2.09
Ratepayer Impact(RIM) $26,734,655 $21,535,882 1.24
ELECTRIC PORTFOLIO (WITHOUT LOW-INCOME)
Cost-Effectiveness Test Benefits Costs Benefit/Cost
Ratio
Total Resource Cost(TRC) $26,550,340 $22,927,977 1.16
Utility Cost Test(UCT) $26,550,340 $18,036,906 1.47
Participant Cost Test(PCT) $41,065,970 $19,406,702 2.12
Ratepayer Impact(RIM) $26,550,340 $20,523,569 1.29
Commercial/Industrial
Mort-7Effectiveness Test Benefits Costs Benefit/Cost
Ratio
Total Resource Cost(TRC) $23,083,221 $18,131,300 1.27
Utility Cost Test(UCT) $23,083,221 $16,337,239 1.41
Participant Cost Test(PCT) $36,707,090 $15,417,930 2.38
Ratepayer Impact(RIM) $23,083,221 $18,638,323 1.24
Residential
Owost-Effectiveness Test Benefits Costs Benefit/Cost
Ratio
Total Resource Cost(TRC) $3,467,119 $4,796,677 0.72
Utility Cost Test(UCT) $3,467,119 $1,699,667 2.04
Participant Cost Test(PCT) $4,358,880 $3,988,771 1.09
Ratepayer Impact(RIM) $3,467,119 $1,885,246 1.84
Low Income
Cost-Effectiveness Test Benefits Costs Benefit/Cost
Total Resource Cost(TRC) $184,315 $892,480 0.21
Utility Cost Test(UCT) $184,315 $1,002,306 0.18
Participant Cost Test(PCT) $1,026,316 $732,175 1.40
Ratepayer Impact(RIM) $184,315 $1,012,313 0.18

Gas Portfolio
Effectiveness Test Benefits Costs Benefit/Cost
low Post- Ratio
Total Resource Cost(TRC) $1,892,976 $2,937,888 0.64
Utility Cost Test(UCT) $1,892,976 $2,254,067 0.84
Participant Cost Test(PCT) $3,700,568 $2,491,413 1.49
Ratepayer Impact(RIM) $1,892,976 $2,372,664 0.80
GAS PORTFOLIO (WITHOUT LOW-INCOME)
Cost-Effectiveness Test Benefits Costs Benefit/Cost
kL- Ratio
Total Resource Cost(TRC) $1,847,974 $2,499,289 0.74
Utility Cost Test(UCT) $1,847,974 $1,754,093 1.05
Participant Cost Test(PCT) $3,178,882 $2,076,104 1.53
Ratepayer Impact(RIM) $1,847,974 $1,870,454 0.99
Commercial/Industrial
ctiveness Test Benefits Benefit/Cost
Ratio
Total Resource Cost(TRC) $224,764 $440,627 0.51
Utility Cost Test(UCT) $224,764 $288,827 0.78
Participant Cost Test(PCT) $347,746 $274,782 1.27
Ratepayer Impact(RIM) $224,764 $306,987 0.73
Residential
Owost-Effectiveness Test Benefits Costs Benefit/Cost
Ratio
Total Resource Cost(TRC) $1,623,210 $2,058,662 0.79
Utility Cost Test(UCT) $1,623,210 $1,465,266 1.11
Participant Cost Test(PCT) $2,831,136 $1,801,322 1.57
Ratepayer Impact(RIM) $1,623,210 $1,563,467 1.04
Low Income
Cost-Effectiveness Test Benefits Costs Benefit/Cost
Ratio
Total Resource Cost(TRC) $45,002 $438,599 0.10
Utility Cost Test(UCT) $45,002 $499,974 0.09
Participant Cost Test(PCT) $521,686 $415,309 1.26
Ratepayer Impact(RIM) $45,002 $502,209 0.09

Appendix D: 2025 Expenditures by Program

Program
Energy Efficiency
Low-Income/CEEP
Low Income $ 842,002 $ 476,684 $ 1,318,685
Residential
Appliances $ 45,553 $ 29,194 $ 74,747
ENERGY STAR Homes $ 12,000 $ 1,200 $ 13,200
Fuel Conversion $ 26,100 $ - $ 26,100
Home Energy Audit $ - $ - $ -
Home Insulation Program $ 8,754 $ - $ 8,754
Residential Midstream $ 560,250 $ 738,100 $ 1,298,350
Residential Shell $ 239,105 $ 439,431 $ 678,536
Commercial/Industrial
Building Operator Certification $ - $ - $ -
Green Motors $ 1,400 $ - $ 1,400
Grocer $ 300 $ - $ 300
Non Residential Midstream $ 74,140 $ 106,564 $ 180,704
Prescriptive Lighting $ 835,378 $ - $ 835,378
Small Business Lighting $ 10,726,872 $ - $ 10,726,872
Non Residential Shell $ 13,883 $ 5,909 $ 19,793
Site Specific-Lighting $ 19,640 $ - $ 19,640
Site Specific-Other $ 1,952,256 $ 10,509 $ 1,962,765
Energy Efficiency Total $ 15,357,632 $ 1,807,592 $ 17,165,224
Northwest Energy Efficiency Alliance $ 885,395 $ 241,374 $ 1,126,769
Market Transformation Total $ 885,395 $ 241,374 $ 1,126,769
Other Programs • Activities
Demand Response $ 15,207 $ - $ 15,207
Education $ 65,240 $ 7,249 $ 72,488
EM&V/CPA $ 294,474 $ 242,168 $ 536,642
General Implementation $ 1,863,208 $ 162,092 $ 2,025,300
Labor $ 1,615,360 $ 261,827 $ 1,877,187
Marketing $ 137,773 $ 15,308 $ 153,081
Pilot $ 37,153 $ 98 $ 37,251
Previous Year Adjustment $ (2,726) $ (3,061) $ (5,786)
Other Programs and Activities Total $ 4,025,689 $ 685,680 $ 4,711,369
Grand Total* $ 20,268,716 $ 2,734,646 $ 23,003,362

Appendix E: 2025 Energy Efficiency Activity by Program

ProgramElectric Natural Gas
Evaluated Evaluated
Energy Efficiency .s Utility Cost Participants Savings .
Weatherization 55 Homes 25,880 $ 171,460 51 Homes 1,805 79,408
HVAC 43 Units 116,232 $ 750,251 34 Units 1,785 $ 240,667
Water Heat - Units - $ - 20 Units 243 $ 77,616
Lighting 2 Units - 78 - NA - $ -
Health and Safety 24 HHS - $ 80,517 29 HHS - $ 102,283
Energy Star Refrigerator - Units - $ - - NA $ -
Low-Income Total 124 111111E 142,112 $ 1,002,306 134 111111M 3,833 $ 499,974
Appliances 569 Units(Measures) 26,382 $ 50,261 283 Units(Measures) 4,123 $ 31,648
ENERGY STAR Homes 12 Homes 44,243 $ 34,617 2 Homes 301 $ 1,939
Fuel Conversion 11 Units(Measures) 82,406 $ 50,948 - Units(Measures) - $ -
Home Energy Audit 108 Homes 86,914 $ 2,512 190 Homes - $
Home Insulation Program 8 Units(Measures) 11,436 $ 14,600 - NA - $ -
Residential Midstream 1,147 Units(Measures) 2,234,477 $ 1,231,137 1,891 Units(Measures) 142,775 $ 940,157
Residential Shell 234 Homes 149,624 $ 315,592 631 Homes 21,209 $ 491,521
sidential Total 2,635,482 $ 1,699,667 ���,408 $ 1,465,266
Building Operator Certification 1 Units(Measures) 119,000 $ 2,484 - Projects $
Green Motors 2 Projects 7,625 $ 1,820 - NA $ -
Grocer 1 Projects 2,919 $ 408 - Projects - $ -
Commercial/Industrial Midstream 69 Projects 163,691 $ 91,513 79 Projects 28,137 $ 259,332
Prescriptive Lighting 471 Projects 3,900,750 $ 1,159,206 - NA - $ -
Small Business Lighting 1,924 Motor Rewind 18,962,969 $ 12,225,641 - NA - $ -
Commercial/Industrial Shell 2 Projects 10,121 $ 14,658 2 Projects 169 $ 6,927
Site Specific 15 Projects 9,511,607 $ 2,841,509 2 Projects 2,838 $ 22,568
C&I Total I 2,485 32,678,682 $ 16,337,239 83---W 31,143 $ 288,827
Energy Efficiency Total 4,698 35,456,276 $ 19,039,212 3,214 203,384 $ 2,254,067

Appendix F: NEEA 2025 Annual Savings Report — Electric

Memorandum >>
March 30, 2026 neea
TO: Nicole Hydzik, Director of Energy Efficiency, Avista Idaho; Amber Gifford, DSM
Planning &Analytics Manager, Avista Idaho; Carlos Limon, DSM Engineer, Avista
Idaho; Meghan Pinch, Manager of Energy Efficiency Programs, Avista Idaho; Kim
Boynton, Manager of Planning and Analytics, Avista Idaho; Reuben J Arts,
Distribution Operations Manager, Avista Idaho
CC: Becky Walker, Chief Program Officer; Stephanie Rider, Director, Portfolio
Management, Reporting & Data Analytics; Nathan Martinez, Director, Market
Analytics, Research and Evaluation; Virginia Mersereau, Vice President, Corporate
Strategy, Relationships and Communications
FROM: Christina Steinhoff, Principal Analysis Manager
SUBJECT: 2025 Annual Savings Report
....................................................0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0...■
NEEA is an alliance of utilities and energy efficiency organizations with a purpose to pool resources
and share risks to transform the market for energy efficiency to the benefit of all consumers in the
Northwest. NEEA works with all parts of the market to deliver energy efficiency to Northwest
consumers by:
• Gathering and analyzing data to inform, market transformation efforts, regional power
planning and utility programs.
• Leveraging its relationships with mid and upstream market actors like manufacturers and
retailers to influence their business practices by making the case for efficiency.
• Improving how products are tested and perform in real life applications.
These long-term efforts transform markets by making more efficient products and options
available to consumers and businesses, leading to energy savings in Avista Idaho's service
territory.
Avista Idaho has requested NEEA to provide an estimate of these savings. This memo provides
final savings estimates for 2025, an update to the preliminary estimates provided in February, and
some highlights of NEEA's work supporting current and future savings streams. The Appendix
contains information about the estimation approach. Additional details by program and measure
are included in the attached spreadsheet.
neea.org I [e-mail]

Please contact Christina Steinhoff, Principal Analysis Manager, at [e-mail] with any
questions about this report.
Final 2025 Savings Estimate Summary
NEEA's estimate of Avista Utilities' Idaho 2025 annual electric energy savings associated with
NEEA's initiatives is 0.78 aMW (Table 1). These values net out an estimate of savings claimed
through Avista Idaho's programs.
Table 1:2025 Final Annual Report Savings Estimates(aMW)
■
Tota 1 0.78
Residential 0.34
Industrial 0.04
Commercial 0.39
Agriculture 0.01
Notes: These are site-based,first year electric savings. Net Market Effects =Total Regional Savings-Local
Program Savings-Baseline Savings.' To calculate the savings, NEEA removes an estimate of savings from
naturally occurring adoption based on baseline trends in the Northwest, and an estimate of savings
reported through Avista Utilities'Idaho local incentive programs (A endix .
Updates to the 2024 Estimates
NEEA updates historical savings estimates based on new data. The 2024 savings decreased by 0.03
aMW primarily because NEEA updated its approach to allocate regional savings from Heat Pump
Water Heater installs based on results from the most recent code compliance studies. NEEA
estimates the savings for heat pump water heaters installed in new and existing construction
separately to account for variations in building energy codes by state. The state-level compliance
studies provide estimates of the share of these installations that are going into new construction
by state. NEEA then uses zip-code-level shipment data from distributors to allocate the remaining
shipments to Idaho service territories. The incorporation of the compliance studies showed a
larger share of the shipments were going into Washington new construction homes than
previously estimated, leading to a decrease in savings allocated to Idaho. NEEA believes the
current estimation could be understating units in Avista's territory and will review additional data
sources for above-code activity to refine this value in 2026. NEEA also updated the new
1 Net Market Effects is savings above the Naturally Occurring Market Baseline established at the start of a program,net of utility
program savings.Total Regional Savings is an estimate of savings since NEEA's market intervention began for the associated
program.
Northwest Energy Efficiency Alliance
421 SW Sixth Avenue, Suite 600, Portland, OR 97204
503.688.5400 1 Fax [phone] Page 2 of 11

construction estimates for both residential and commercial new construction based on revisions
from Dodge Analytics and the Department of Housing and Urban Development and will continue
to track these updates annually.
2025 Highlights
NEEA collaborates with stakeholders across the Northwest and nationally to advance the adoption
of energy efficient technologies. Work includes:
• Data collection, research, and analysis
• Product development and testing
• Market implementation
These efforts help bring higher efficiency products and services to market, ultimately benefiting
consumers and businesses, and generating energy efficiency savings. Below are key highlights for
2025.
Data collection, research, and analysis
Building Stock Assessments
NEEA has five regional studies that hit milestones in 2025. The data collection phase of the 2025
Commercial Building Stock Assessment finished, and the study began developing data and
reporting deliverables that will be posted on neea.org in the first half of 2026. The Home Energy
Metering Study and Commercial Energy Metering Study both finished metering and deinstalled
most meters. The study will now focus on analyzing the data and sharing key insights. The Motor-
System Stock Assessment selected and onboarded two firms and began study-design and planning
work. Lastly, NEEA formed the 2027 Residential Building Stock Assessment working group and with
their input developed a request for proposals document that will be released at the beginning of
2026.
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, building codes, and new
product standards work, as well as NEEA's special project work in end use load flexibility and
whole building/building performance standards. The team led work on eight program market
progress evaluations in 2025, including for two Commercial HVAC programs, the Extended Motor
Products— Pumps, Luminaire Level Lighting Controls, Heat Pump Water Heaters, Retail Product
Portfolio, and Advanced Heat Pump programs, as well as for NEEA's building energy codes work.
These mixed-method, longitudinal evaluations are instrumental to understanding the market
opportunity for these measures and for tracking NEEA's progress toward its Market
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Transformation goals. In addition, the team managed work on four projects that measured
compliance with updated building energy codes in Idaho, Montana, and Oregon. These projects,
along with the codes' market progress evaluation and a review of NEEA's approach for developing
counterfactual baselines for state energy codes, provide the market with valuable information on
the market's response to code changes, informs strategy, and supports evaluation of NEEA and its
partners' influence on building energy codes.
Data Processing
NEEA brought retail data processing in-house, providing greater visibility, flexibility, and more
detail in the resulting market insights. The dataset includes retail sales from four large retailers
and covers both qualifying and non-qualifying ENERGY STAR products, including clothes washers,
clothes dryers, heat pump water heaters, and refrigerators.
NEEA also completed development of a data pipeline to estimate market share of ENERGY STAR v9
televisions and continues to make improvements to model-matching over time. NEEA
commissioned a third-party review of the savings calculation method and other key assumptions
for televisions. This review helped refine the work in some key areas and provided third-party
validation of the methods NEEA developed. This report will be published in early 2026.
Product Development and Testing
Emerging Technology
NEEA's emerging tech team routinely scans for, assesses, and reports on the potential for newly
identified efficient products, services, and practices. Once opportunities are identified, NEEA
works with manufacturers to encourage creating products that meet regional needs and truly save
energy. As a regional organization, NEEA focuses on opportunities that have broad benefits across
the four Northwest states, including places that have unique barriers and opportunities for
efficiency, such as rural markets and colder climates. By working together and aggregating
investment, NEEA's funders and stakeholders share both the cost and the risks associated with
bringing new energy efficient technology to markets.
In 2025, the emerging technology program conducted research across a wide range of product
groups including:
• Consumer Products
o ENERGY STAR drew heavily from NEEA's Advanced Water Heating Specification to
create the final test method for Central Heat Pump Water Heater Systems.
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o NEEA identified improvements to refrigerator test methods that will better account
for energy saving features included in the newest generation refrigerators. NEEA
will use this information to influence future test procedures.
o Field research into current laundry usage patterns began in 2025 with a planned
publication date in Q2 of 2026. This research also includes an analysis of test
methods that may simplify and reduce the cost of maintaining a qualified products
list for efficient dryers. Findings from field research will allow the Regional
Technical Forum to update dryer measures with more current assumptions,
expected in Q3 of 2026.
o NEEA explored the energy efficiency potential of heat pump commercial tumble
dryers via lab investigations to assess performance, cost-effectiveness evaluations
for hotel expenditures, and estimates of regional and national energy savings.2
Study findings revealed key insights into commercial tumble dryer efficiency and
identified opportunities for further research tailored to the hotel industry's needs
as well as the broader market. Additionally, findings will support manufacturers in
refining commercial dryer product designs to better serve the U.S. market. Finally,
NEEA plans to continue its collaboration with the commercial tumble dryer
manufacturer to support design adjustments that can enhance the performance of
current models.
o NEEA is piloting a Northwest online marketplace. The site provides a one-stop shop
for efficient products, customized for Avista Idaho's customers. The platform
includes EcoFinancing along with an Energy Score to help shoppers quickly identify
efficient options when they need to replace their appliances quickly.
• HVAC
o NEEA started a field study of 13 homes to investigate the flexibility and affordability
benefits of dual-fuel residential HVAC systems in various climate and energy market
conditions.
o NEEA is nearing completion of a field and energy modeling study to test the
benefits of integrating lighting and HVAC controls which will expand the product
and benefits of NEEA's current Luminaire Level Lighting Controls program. The
crosscutting control system technology could provide a new avenue for energy
savings in small-to-medium commercial buildings where control systems are not
typical.
z Kannah Consulting.2025.Commercial Heat Pump Tumble Dryers-Efficiency Testing,Operations Considerations,and Energy
Savings.
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o NEEA partnered with Bonneville Power Administration to install and monitor 34
room heat pump systems to collect both customer experience information and
operational runtime and setting data.
• Motor Systems
o NEEA investigated opportunities for increased pump efficiencies with American
National Standards Institute (ANSI) pumps. NEEA is working to develop a Pump
Efficiency Index for ANSI pumps which, while not exclusively used for clean water,
generally pump fluids with very similar properties to clean water. NEEA should have
findings from its research in 2026.
Test Procedures and Energy Efficiency Standards
In 2025, NEEA staff served as an important voice in representing utility, industry, and market-wide
impacts from Department of Energy (DOE) proposed rollbacks to certain Federal efficiency
standards. DOE has not yet issued final rules on these proposed rollbacks, which may be due, in
part, to the breadth and depth of comments submitted by NEEA and other stakeholders
representing a diverse group of manufacturers, industry trade associations, energy-efficiency
advocacy groups, consumer advocates, and state and local government representatives. As DOE's
standards program is not as active at the Federal level, NEEA has also been active in supporting
state agencies in the Pacific Northwest to ensure that effective and efficient products continue to
be available for consumers, as well as focusing on the development and improvement of test
procedures for several products, including clothes dryers, televisions, and refrigerators. These
new test procedures will ensure that the latest technology is adequately represented and yield
metrics that can effectively differentiate better-performing equipment in the market. NEEA
updated four codes and standards strategies for several NEEA Market Transformation programs
and is in the process of completing and implementing strategies for five additional programs or
special projects.
Market Implementation
HVAC Programs
NEEA continued work to identify and drive adoption of product features, capabilities, and ratings
that will elevate the efficient performance of all residential two-stage and variable-speed heat
pumps installed in the Northwest. The new Advanced Heat Pumps, which has a Total Regional
Savings potential of 35 aMW for the Northwest, focuses on residential heat pumps with the
following improvements: low-load efficiency, cold-climate capability, minimized supplemental
heat, connected commissioning, and automatic load flexibility. Along with national partners, NEEA
leads the Advanced Heat Pump Coalition to pursue technical advancements in residential heat
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pumps and support utility heat pump programs. This coalition consists of more than 140
participating utilities and other efficiency organizations including 13 northwest utilities. In
addition, NEEA and partners co-facilitated a symposium of manufacturers, distributors and utility
representatives, collaborating to promote ways for the region to address reducing the use of
supplemental electric resistance heat with heat pump systems, developing installer training and
consumer messaging.
In 2025, the program focused on:
• Introducing four new heat pump product improvement recommendations to more than a
dozen manufacturers to boost product adoption in the region.
• Completing a multi-year research effort with results suggesting low-load efficient variable
speed heat pumps could deliver 2-7% energy savings with little-to-no increase in system
cost, supporting improved cost effectiveness of heat pumps in the region.'
• Submitting a heat pump measure proposal to the RTF, focused on minimizing the use of
supplemental electric resistance heat with residential heat pump installs.
• Developing a connected commissioning certification with a future aim of establishing a
national registry that hosts a qualified product list (QPL) of connected commissioning
capable products to help HVAC technicians and utilities identify these products.
Water Heating
NEEA worked with the Advanced Water Heater Initiative'to identify barriers and opportunities to
help consumers adopt and benefit from the new federal standard mandating a shift for most
electric storage water heaters to heat pump technology by 2029. NEEA also expanded the number
of qualified regional installers and supported technological advancements through collaboration
with manufacturers. NEEA is forecasting that heat pump water heaters can bring the Northwest
more than 400 aMW of Total Regional Savings.
Consumer Products
Through its Retail Products Portfolio program (RPP), NEEA works with retailers and extra-regional
program administrators to utilize midstream incentives that signal energy-efficient options in the
supply chain and in turn provide full-category sales data. NEEA's involvement influences practices
across the supply chain, encouraging commitment from manufacturers and retailers to build,
purchase, stock, and promote high-efficiency products. Products include white goods, air cleaners,
3 Harley Energy Consulting,LLC;Cadeo Group,LLC;Cener for Energy and Environment;DNV;OTS Energy,LLC;TRC Companies;UL
Plano Texas;University of Nebraska Lab.2025.Low-Load Efficient Heat Pump Investigation:2020-2025 Summary Report.
4 AWHI is a member-funded collaborative of building owners,utilities,federal agencies,state and local governments,
manufacturers,engineers,installers,advocates,researchers,and building industry professionals from across the U.S.
Northwest Energy Efficiency Alliance
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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. NEEA is forecasting that the
ENERGY STAR products NEEA is working on could bring the Northwest more than 150 aMW of
Total Regional Savings.
NEEA worked actively in three product categories in 2025, focusing on ensuring accurate test
procedures and developing new strategic pathways to spur adoption.
• Refrigerators:
o NEEA scoped a multi-phase lab testing effort to first assess various available test
methods that value the performance of advanced adaptive compressors and then
perform testing on a sample of refrigerators. The goal is a proof-of-concept where
additional EE advocates or manufacturers can fund the lab testing to fully populate
a new QPL for advanced refrigerators. NEEA is leading the development of the new
QPL to help manufacturers and consumers recognize the energy savings from
adaptive compressor technology and to influence updates to the DOE test
procedures.
• Laundry:
o In February 2025, the new leadership at the US Department of Energy announced
indefinite postponements of the effective dates for federal standards on laundry
appliances. Standards for both washers and dryers were adopted in 2024 through a
process that was influenced by NEEA and other EE advocates and included a
negotiated agreement with the Association of Home Appliance Manufacturers.
NEEA is remaining in coalition with other advocates to be prepared to take
advantage of the next opportunity to establish a firm effective date for these
energy and money saving minimum efficiency levels.
o NEEA gathered cost data to conduct analysis on the affordability of ENERGY STAR
laundry appliances with the intent of identifying products and features that are
common amongst ENERGY STAR products in the low-cost range. NEEA is currently
exploring its approach to incorporate affordability strategies in our market
transformation work.
• Televisions:
o NEEA partnered with Best Buy and Costco to support in-store promotions of
ENERGY STAR televisions in late 2025. The promotions encourage consumers to
choose the most efficient options while prompting retailers to market and
manufacturers to certify televisions through ENERGY STAR.
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Lighting
NEEA engages commercial lighting manufacturers and their supply chain to increase adoption of
Luminaire Level Lighting Controls (LLLC) in the Northwest. NEEA is forecasting that these controls
could bring the Northwest more than 40 aMW of Total Regional Savings. Findings from a 2025
evaluation show that the demand for LLLC continues to experience year-over-year growth.5
Product awareness is now nearly universal among installers, and increasing percentages of
installers and designer/specifiers reported an ability to bid on projects that include these controls.
To maintain momentum, NEEA will continue training and strengthening sales staff's ability to
articulate the value of LLLC across different building types and applications. NEEA's
implementation contractor led three in-person sessions and one webinar in Idaho in 2025. The
sessions drew 97 attendees, primarily contractors and end-use customers. The training focused on
the simplicity of LLLC installation and how to take advantage of local incentives.
Motor-Driven Systems
NEEA is now reporting agricultural savings from smart pump installations in Idaho. NEEA's
Extended Motor Products - Pumps program has been collaborating with manufacturer
representatives to increase awareness of smart pump technologies and provide tools that
demonstrate their value across sectors. The program has also partnered with the Hydraulic
Institute to enhance awareness and usage of the Energy Rating label. NEEA is forecasting that
these efficient pumps could bring the Northwest more than 25 aMW of Total Regional Savings.
New Construction
NEEA continues to advance innovation within the supply chain while helping shape voluntary
specifications and codes to ensure consumers and building owners have access to products that
perform reliably and save energy.
In 2025, NEEA actively participated in the development process for the 2027 International Energy
Conservation Code (IECC). Staff served on the Commercial Consensus Committee, the Commercial
HVAC subgroup, and the Residential Modeling & Whole Building subgroup. During the first round
of development, NEEA submitted four code change proposals, three as lead proponent and one as
co-proponent. One proposal was approved for inclusion in the first draft of the 2027 IECC.
NEEA also completed a code compliance evaluation for Idaho's 2018 IECC (commercial).'The study
examined compliance pathways and assessed the level of compliance achieved. Findings from this
5 Cadmus, 2025, Luminaire Level Lighting Controls: Market Progress Evaluation Report#3
6 Opinion Dynamics.2025. Idaho 2018 Commercial New Construction Code Compliance Evaluation.
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analysis will guide NEEA's market intervention strategies for new construction, including future
training and education programs.
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Appendix
Allocation Methodology
Avista Idaho requests a savings report that best represents activity in its service territory where
possible. NEEA uses the best available data to estimate these shares. Details about the allocation
approaches and data sources by program are available on the Service Territory Data Sources
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, utilities,
and other NEEA 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 RTF.
Additional information about savings assumptions, methodologies, and data sources will be
available with the savings reports on our new online funder portal. The new system provides a
secure platform to share information as well as creates an archive of prior shared documents.
Individuals who already have an account should have received an email containing the link to the
portal. Upon accessing the portal, users should sign in using their credentials (email address and
password). Those who do not have an account or who have any other questions should contact
Chris Clark, NEEA Analyst, External Reporting and Special Projects, at [e-mail].
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Appendix G: NEEA 2025 Annual Savings Report — Natural Gas

Memorandum I
March 25, 2026 In ,
TO: Nicole Hydzik, Director of Energy Efficiency,Avista Idaho; Amber Gifford, DSM Planning&
Analytics Manager,Avista Idaho; Carlos Limon, DSM Engineer,Avista Idaho; Meghan Pinch,
Manager of Energy Efficiency Programs,Avista Idaho; Kim Boynton, Manager of Planning
and Analytics,Avista Idaho; Reuben J Arts, Distribution Operations Manager,Avista Idaho
CC: Becky Walker, Chief Program Officer; Stephanie Rider, Director, Portfolio Management,
Reporting& Data Analytics; Nathan Martinez, Director, Market Analytics, Research and
Evaluation;Virginia Mersereau,Vice President of Corporate Strategy and Communications
FROM: Christina Steinhoff, Principal Analysis Manager
SUBJECT: Final 2025 Annual Natural Gas Savings Report
................................................................................
NEEA is an alliance of utilities and energy efficiency organizations with a purpose to pool resources and
share risks to transform markets for energy efficiency to the benefit of all consumers in the Northwest.
NEEA works with all parts of the market to deliver energy efficiency to Northwest consumers by:
• Gathering and analyzing data to inform market transformation efforts, regional power
planning, and utility programs.
• Leveraging its relationships with mid and upstream market actors like manufacturers and
retailers to influence their business practices by making a case for efficiency.
• Improving how products are tested and perform in real life applications.
Utilities, energy efficiency administrators, and the Regional Technical Forum (RTF) all benefit from NEEA's
work through knowledge sharing, the development of new energy conservation measures, and the
resulting market changes leading to energy savings.
These long-term efforts transform markets by making more efficient products and options available to
consumers and businesses across the Northwest. NEEA's end goal is to make energy efficiency a self-
sustaining standard of practice in markets.
As such,Avista Utilities Idaho has requested an annual savings report.This memo provides:
• Natural gas energy savings for 2025
• An update to the 2024 savings estimates based on new data.
• Highlights of work in 2025 to help support the region meet its energy conservation goals.
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neea.orq I [e-mail]
Page 1 of 8

Details about the allocation, baseline, and technical assumptions are in the attached Excel spreadsheet.
Please contact Christina Steinhoff at [e-mail] with any questions about this report.
2025 Savings Estimate
NEEA estimates Avista Utilities Idaho's 2025 annual natural gas energy savings associated with its initiatives
is 302,208 Annual Therms' (Table 1). These savings are above the NEEA baseline and exclude an estimate
of savings that Avista Utilities and other regional utilities claim through locally run programs. NEEA allocates
energy savings based on an estimate of service territory shares (Appendix). Many gas-funded programs are
still in early development. NEEA expects the savings from these programs to increase over the next few
years.
The programs in the gas portfolio are very early in the market and still developing out as opportunities
within each funder's territory. NEEA reports energy savings at the service territory level, and there may be
years when a program in early development will not have any trackable adoption to report. NEEA sees
market progress occurring across the region and forecasts benefits for each funder over the business
cycle. NEEA is currently seeking local demonstration projects to develop local level learnings and
relationships to support early adoption in Avista Utilities' territory. Contact Alisyn Maggiora, Sr.
Stakeholder Relations Manager, at [e-mail] for more information.
Table 1:2025 Annual Report Net Market Effects Savings*Estimates(Annual Therms)
. . 302,208
Gas-funded Programs 300,968
Efficient Rooftop Units (ERTU) 0
Product Standards (Commercial) 0
Product Standards (Residential) Expected in 2029
New Construction (Commercial Codes) 0
New Construction (Residential Codes) 300,968
Gas-funded Programs in Development NA
Advanced Commercial Water Heating Expected in 2026
High Efficiency Dedicated Outdoor Air System (HE DOAS) Expected in 2027/2028
Indirect Gas Savings 1,239
Manufactured Homes (Envelope Measures) 1,059
Extended Motor Products-Pumps (Commercial, Water Heating) 0
Extended Motor Products-Pumps (Residential, Water Heating) 180
*Net Market Effects=Total Regional Savings-Local Program Savings-Baseline Savings
1 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 Avista Idaho's market
intervention.
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New to this Report
This report now includes an Indirect Gas Savings section for savings achieved from alliance investments
outside of the gas portfolio. NEEA's relationships with market actors, influence in national collaboratives
and voluntary standards, and market-facing materials can benefit energy use across all fuel sources.As
NEEA expands its understanding of overlap between its electric and gas portfolios, staff have identified
situations where market transformation efforts funded through the electric portfolio have produced
measurable gas savings. NEEA categorizes these savings as indirect, reportable savings because these gas
benefits are not the primary goal of the program strategy. The areas where NEEA has currently identified
measurable indirect gas savings include:
• Manufactured Homes: NEEA developed enhanced, above-code specifications that improve building
envelopes and deliver both electric and gas savings. NEEA tracks these savings and continues to
support federal efforts to incorporate the specifications into U.S. Department of Energy standards.
• Extended Motor Products (XMP)-Pumps: NEEA influenced the development of an energy rating
label to increase awareness and understanding of smart pump technology. High-efficiency pumps
can reduce both gas and electric water heating energy use. NEEA tracks these savings through its
XMP-Pumps program.
More information about these programs is available upon request.
2024 Annual Report Update
The 2024 savings increased by less than 1 percent to 287,059 MM Therms. NEEA updated the new
construction estimates for residential buildings based on revisions from the Department of Housing and
Urban Development. Table 2 shows the changes.
Table 2:Update to the 2024 Annual Savings Estimates(Annual Therms)
2024 Annual Report
. . 285,431 287,059
2025 Highlights
NEEA collaborates with stakeholders across the Northwest and nationally to advance the adoption of
energy efficient technologies. Work includes:
• Data collection, research, and analysis
• Product development and testing
• Market implementation
These efforts help bring higher efficiency products and services to market, ultimately benefiting consumers
and businesses, and generating energy efficiency savings. Below are key highlights for 2025.
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Data Collection, Research, and Analysis
Building Stock Assessments
NEEA has five regional studies that hit milestones in 2025.The data collection phase of the 2025
Commercial Building Stock Assessment finished, and the study began developing data and reporting
deliverables that will be posted on neea.org in the first half of 2026.The Home Energy Metering Study and
Commercial Energy Metering Study both finished metering and deinstalled most meters.The study will now
focus on analyzing the data and sharing key insights.The Motor-System Stock Assessment selected and
onboarded two firms and began study-design and planning work. Lastly, NEEA formed the 2027 Residential
Building Stock Assessment working group and with their input developed a request for proposals document
that will be released at the beginning of 2026.
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, building codes, and new product standards
work, as well as NEEA's special project work in end use load flexibility and whole building/building
performance standards. Some gas-related research included:
• Identifying purchase motivators for people with high-efficiency gas equipment to see if and where
there is a market for a commercialized gas heat pump water heater.3
• Exploring the opportunities and barriers for adding gas to NEEA's High-Performance HVAC program,
characterizing the market landscape, and assessing specifiers' perceptions of system configurations
in hypothetical scenarios aligned with the program's targeted approach.4
• Increasing the region's understanding of gas and electric water heating systems across a selection
of commercial buildings in the Northwest.'
• Completing the first Market Progress Evaluation Report for the Efficient Rooftop Units (ERTU)
program.' The study found that six manufacturers currently offer ERTU products, including two of
the five leading ERTU manufacturers. While adoption is still emerging, integrated energy recovery
ventilator models appear to be gaining more traction than bolt-on options.
In addition,the team managed work on projects that measured compliance with updated building energy
codes in Idaho, and Oregon.These projects, along with the codes' market progress evaluation and a review
of NEEA's approach for developing counterfactual baselines for state energy codes, provide the market
with valuable information on the market's response to code changes, informs strategy, and supports
evaluation of NEEA and its partners' influence on building energy codes.
3 High Efficiency Gas Water Heater Research -Northwest Energy Efficiency Alliance(NEEA)
4 Commercial HVAC Specifier Market Research: Gas High Efficiency DOAS - Northwest Energy Efficiency Alliance
(NEEA)
5 Market Research on Existing Water Heaters in Select Commercial Buildings, Final Report-Northwest Energy
Efficiency Alliance(NEEA)
6 Efficient Rooftop Units Market Progress Evaluation Report#1 -Northwest Energy Efficiency Alliance(NEEA)
neea.org I [e-mail]
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Data Processing
NEEA continued to refine its commercial HVAC installation tracking process as well as expand market
coverage. NEEA collects sales data, relying on trusted relationships with regional HVAC suppliers. NEEA
augments the data by matching equipment model numbers to equipment efficiency attributes from the Air-
Conditioning, Heating, and Refrigeration Institute certification database. NEEA's goal is to continue
minimizing manual data cleaning and to expand its coverage with distributors as well as add sales through
manufacturer representatives.
Product Development and Testing
Emerging Technology
NEEA's emerging technology team routinely scans for, assesses, and reports on the potential for newly
identified efficient products, services, and practices. Once opportunities are identified, NEEA works with
manufacturers to encourage creating products that meet regional needs and are confirmed to save energy.
As a regional organization, NEEA focuses on opportunities that have broad benefits across the four
Northwest states, including places that have unique barriers and opportunities for efficiency, such as rural
markets and colder climates. By working together and aggregating investment, NEEA's funders and
stakeholders share both the costs and the risks associated with bringing new energy efficient technology to
markets.
In 2025,the emerging technology program conducted research to scan new products for NEEA's gas energy
efficiency portfolio.The work included:
• A field study of 13 homes to investigate the flexibility and affordability benefits of dual-fuel
residential HVAC systems in various climate and energy market conditions.
• A field and energy modeling study to test the benefits of integrating lighting and HVAC controls to
expand the product and benefits of NEEA's current Luminaire Level Lighting Controls program.The
crosscutting control system technology could provide a new avenue for energy savings in small-to-
medium commercial buildings where control systems are not typical.
• A test of residential-sized gas fired absorption heat pump design for broad residential and
commercial applications. Field data showed the hybrid system could achieve net efficiencies of up
to 136%,with gas savings of 54% in hot water-only mode and up to 55% in combined heating
modes at the multifamily site.At the residential sites,the system achieved net efficiencies between
110%and 130% in combined heating modes.'
Test Procedures and Energy Efficiency Standards
In 2025, NEEA staff served as an important voice in representing utility, industry, and market-wide impacts
from Department of Energy (DOE) proposed rollbacks to certain Federal efficiency standards. The DOE has
not yet issued final rules on these proposed rollbacks, which may be due, in part,to the breadth and depth
of comments submitted by NEEA and other stakeholders representing a diverse group of manufacturers,
7 Gas-Fired Absorption Heat Pump: Hybrid System Approach Field Study-Northwest Energy Efficiency Alliance(NEEA)
neea.org I [e-mail]
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industry trade associations, energy-efficiency advocacy groups, consumer advocates, and state and local
government representatives. Because the DOE's standards program is not as active at the Federal level,
NEEA has also been active in supporting state agencies in the Pacific Northwest to ensure that effective and
efficient products continue to be available for consumers, as well as focusing on the development and
improvement of test procedures for several products. These new test procedures will ensure that the
latest technology is adequately represented and yield metrics that can effectively differentiate better-
performing equipment in the market.
Market Implementation
Efficient Rooftop Units
In 2025,the program developed four new marketing resources:
• A case study for the KBOO Community Radio field demonstration,
• A re-design of the BetterBricks Efficient Rooftop Units page,
• A brochure for distributors that explains the benefits of the ERTU specification elements,
• A one-page flyer on ERTU program details.
The team also started development on a website campaign for 2026 that will help building owners or
facility managers identify how ERTUs would be a good option for HVAC equipment replacement projects.
The program has made progress with manufacturer representatives identifying projects and applications
suited for qualified efficient RTUs (e.g. schools, sports facilities, and other building types with high-
ventilation needs).The program is looking to incentivize case study development and support for
manufacturer representatives promoting qualified products.
The program also kicked off the Energy Recovery Ventilators/Heat Recovery Ventilators cleaning market
study with MarketWise. Objectives are to gather perspectives on operational considerations for installing,
commissioning, cleaning, and maintaining ERVs/HRVs, and investigate what ERV/HRV cleaning and
maintenance looks like in real-world applications. A final report will be available in 2026.
Finally, NEEA completed a modeling study on commercial HVAC efficiency measures for various types of
commercial rooftop units.The goal of broadening the modeling efforts to cover a greater portion of the
United States is to enhance the region's understanding of how measure and tier impacts vary by climate
region,which could eventually inform the development of a national program applicable to the RTU market
and representative federal efficiency metrics for this product.'
High Efficiency Dedicated Outside Air Systems
NEEA is exploring opportunities to expand its Commercial High-Performance HVAC electric program to
include gas products.The team is assessing the projected market potential, savings estimates, cost
effectiveness, and barriers/opportunities to present to NEEA's gas-funding stakeholders in 2026.
8 National Efficient Rooftop Unit Energy Modeling -Northwest Energy Efficiency Alliance(NEEA)
neea.org I [e-mail]
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Water Heating
The Advanced Commercial Water Heating program finished a market characterization report that should be
published later this year. NEEA also continued engagement with manufacturers and tested the products
through field demonstrations including a commercial gas heat pump system. NEEA is working with the
North American Gas Heat Pump Collaborative on a new feasibility study to identify potential savings and
market opportunities for a gas system for use in the commercial multifamily market. NEEA is also co-
funding a Gas Technology Institute project to develop a new tool for designing and optimizing commercial
water heating gas heat pump systems.
The research and analysis will help the program move into market development in 2026/2027.
New Construction
NEEA continues to advance innovation within the supply chain while helping shape voluntary specifications
and codes to ensure consumers and building owners have access to products that perform reliably and save
energy.
In 2025, NEEA actively participated in the development process for the 2027 International Energy
Conservation Code (IECC). Staff served on the Commercial Consensus Committee, the Commercial HVAC
subgroup, and the Residential Modeling&Whole Building subgroup. During the first round of development,
NEEA submitted four code change proposals,three as lead proponent and one as co-proponent. One
proposal was approved for inclusion in the first draft of the 2027 IECC.
NEEA also completed a code compliance evaluation for Idaho's 2018 IECC (commercial).'The study
examined compliance pathways and assessed the level of compliance achieved. Findings from this analysis
will guide NEEA's market intervention strategies for new construction, including future training and
education programs.
9 Opinion Dynamics. 2025. Idaho 2018 Commercial New Construction Code Compliance Evaluation.
neea.org I [e-mail]
Page 7 of 8

Appendix: Methodology
Allocation
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, Avista Idaho 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 RTF.
Details are available within the spreadsheet accompanying this memo.
Additional information about savings assumptions, methodologies, and data sources will be available with
the savings reports on our new online funder portal.The new system provides a secure platform to share
information as well as creates an archive of prior shared documents.
Individuals who already have an account should have received an email containing the link to the
portal. Upon accessing the portal, users should sign in using their credentials (email address and
password).Those who do not have an account or who have any other questions should contact Chris Clark,
NEEA Analyst, External Reporting and Special Projects, at [e-mail]�.
neea.org I [e-mail]
Page 8 of 8

Appendix H: NEEA 2025 Annual Savings Report Addendum

REPORTANNUAL SAVINGS 11
2025 //A vista Utilities
Introduction
The Northwest Energy Efficiency Alliance (NEEA) is an alliance of utilities and energy efficiency
organizations working on behalf of over 14.5 million energy consumers across the four Northwest states.
NEEA's mission is to catalyze the most efficient use of energy for a thriving Northwest.
NEEA is funded by more than 140 electric and natural gas utilities and program administrators across the
region, including Avista Utilities, Idaho Power, the Bonneville Power Administration and Energy Trust of
Oregon. Its stakeholders include Northwest utilities, public interest groups, state energy offices and
government entities. Since 1996, NEEA has taken a market-driven approach to energy efficiency that is
grounded in data, collaboration and rigorous evaluation. NEEA works to transform markets by filling
information gaps and identifying and removing barriers so the market can align around evolving electric
and natural gas energy efficiency needs. The result is long-term, cost-effective energy savings for the
region.
In 2023, through a jointly issued Request for Proposals with Idaho Power, Avista Utilities commissioned
ADM Associates, Inc. to conduct an evaluation of the methods that NEEA uses to evaluate its influence in
Idaho. ADM made several recommendations for additional reporting from NEEA beginning in 2025. This
addendum responds specifically to the following recommendations:
• Recommendation #2: Request that annual savings reports include estimates of administrative
expenses, incentive expenses and non-incentive expenses by service territory.
• Recommendation #4: Track progress for each code change relative to administrative dollars spent
towards state-level codes and associated energy savings accrued by each state-level code.
This addendum to NEEA's annual savings report addresses these recommendations by providing Avista
Utilities with additional expense details.
Please note, the annual budget provided in this addendum supports both current and future energy
savings from NEEA's activities. As annual expenses are not directly tied to same-year annual savings,
NEEA does not recommend using this report for annual utility cost-effectiveness evaluations. Doing so
would not capture the full scope of investment and return, nor would it support proper decision making.
2025 BUDGET ALLOCATION BY EXPENSE CATEGORY
The table below details the proportion of NEEA's total regional 2025 expenses allocated to Avista Utilities
broken out by administrative expenses, incentives and other expenses. Estimates are based on NEEA's
standard funding formula, which was adopted by NEEA's Board of Directors to determine funding shares
for each direct funder. Please note the figures are rounded to the nearest dollar.
NEEA Avista Utilities 2025 Annual Report/ 1

Mid-Stream/ Total 2025
NEEA Funder Administrative Upstream Non-incentive Expenses
Expenses' IncentiveS2 Expenses allocated to
Avista
Avista Utilities
(Idaho) (2.18% Electric $125,240 $51,605 $615,896 $792,741
of NEEA's
Electric &
3.82% of
NEEA's Natural Natural
Gas funding Gas $31,980 $245 $170,200 $202,425
share)
2025 EXPENSES RELATIVE TO CODE CHANGE PROGRESS
NEEA supports energy codes across the Northwest through a broad range of efforts including training,
collaboration and technical engagement. This includes contributing to the development of the
International Energy Conservation Code (IECC)and supporting state-level code updates in Idaho,
Montana, Oregon and Washington. NEEA also provides training and resources to help implement new
codes effectively, provides data to inform future code changes, and works with utilities to align new
construction programs with evolving standards.
2025 ACTIVITIES (IDAHO)
Idaho began a formal rulemaking process in 2025 to update state energy codes, anchored to the 2024
IECC reference code. NEEA staff facilitated a code collaborative that helped to inform, link and build
consensus across a broad range of members participating in the public process, including public hearings
with the Building Code Board. NEEA staff virtually attended state meetings, tracked amendment
outcomes, and coordinated stakeholder feedback throughout the 2025 process. Trainings, technical
materials and new construction support were provided throughout the year and through BetterBuiltNW. In
addition, NEEA staff co-developed and submitted proposals for the 2027 IECC national model code and
served on multiple national consensus committees formed to guide the final IECC code.
The table below details Avista's portion of NEEA's Idaho-specific activities and expenses in 2025
supporting Idaho's residential and commercial energy code. The expenses are based on activities in
Idaho (e.g., training and research) and expenses for supporting materials (e.g., the BetterBuiltNW
website, the AXIS database for new construction, and 2027 IECC development). Please note the figures
are rounded to the nearest dollar.
'Administrative expenses reflect Funders'proportional share of costs for non-program expenses related to company management and overall
operations using the same methodology as reflected in NEEA's Form 990 annual tax return.
2 Financial incentives paid by NEEA to manufacturers,distributors and other midstream and upstream supply chain participants.
NEEA Avista Utilities 2025 Annual Report/ 2

2025 Labor and Project ExpenseS3 by Activity—Avista's Portion
Codes Collaborative and Training Dedicated contract for activities in Idaho $53,997
Residential and Commercial Code Dedicated contract for research in Idaho $31,790
Evaluations
New Construction Tools and Support Shared regional resource $7,797
Codes and Technologies Training Regional resource customized for Idaho $7,193
Codes Energy Savings Analysis Shared regional resource $3,020
Educational Content for all New BetterBuiltNW and other resources $1,036
Construction
Total $104,833
Questions? Contact Us
Mark Rehley Kyle Burchard
Director, Codes, Standards Vice President of Business
and Emerging Technology Administration
mrehley(a)neea.org kburchard(a)neea.org
3 Code expenses include NEEA labor to support code work,code research and evaluation,codes training and education.Expenses from regional
activities were divided using funder allocations across states,and the total state value was distributed between utilities using funder shares.
NEEA Avista Utilities 2025 Annual Report/ 3

Appendix I:
2025 Energy Efficiency Advisory Group Meetings & Agenda Topics
Meeting 1: March 4, 2025
Agenda
1) 2022-2023 Savings Achievements
■ 2022-2023 Biennial Conservation Report: UTC Dockets UE-210826 and
UG-210827
■ 2022-2023 Idaho Prudence Determination
2) 2025 Annual Conservation Report Overview
3) Cost Effectiveness of Natural Gas Programs in Idaho
4) Annual Conservation Report Process Improvements
5) Program Updates
■ Small Business Lighting
■ Home Energy Reports (HERs)
■ Insulation Direct Install
6) Looking Ahead in 2025: Biennial Conservation Plan Process; CEIP; Public
Participation
Meeting 2: May 14, 2025
Agenda
1) 2024 Reported Achievements
2) CPA Contract Update
3) Preparing for the Biennial Target-setting Process
4) Discussion: Project Incremental Costs
5) Home Energy Reports Update — Design Elements
6) Deferred Maintenance Update & Recap
7) Weatherization Training Plans
8) Building Operator Certification Training Update
9) Additional Program Updates
■ Insulation DI Program
■ Compressed Air
■ Cohort for Multifamily SEM
■ Midstream RFP
10)Discussion: DEA as it pertains to Energy Efficiency
11)Upcoming Dates/Deadlines
Meeting 3: June 25, 2025
Agenda
1) 2024 Preliminary Idaho Achievements
2) 2026-2027 Biennial Target Setting Process
3) Idaho Natural Gas Program Analysis — Cost Effectiveness
4) Program Updates:

■ Home Insulation Program
■ Multifamily Energy Excellence Program
5) Discussion: Program Opportunities for Next 2 Years
6) Upcoming Meetings and Filing Dates
Meeting 4: August 25, 2025
Agenda
1) Idaho-Specific Topics (2024 achievements)
2) 2026-2027 Biennial Conservation Plan
3) CETA Topics
■ 2025 CEIP — Named Communities & CBI
■ Procedural Equity
■ CETA Program Continuity
4) Upcoming Meetings and Filings
5) Public Participation Dates
Meeting 5: October 21, 2025
Agenda
1) Home Energy Reports Program
■ Joint Presentation from Bidgely &ADM
2) EE Program Updates for 2026
3) New Engineering Pilot Programs for 2026
4) Year-to-Date Savings Updates for Washington & Idaho
5) EE Customer Demographics
6) WA Biennial Conservation Plan draft updates
7) Upcoming Meetings & Filings
8) Public Participation Dates