20241220Application Attachment 1.pdf

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2023
ANNUAL REPORT
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TABLE OF CONTENTS
EXECUTIVE SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
COST-EFFECTIVENESS TESTING METHOD . . . . . . . . . . . 4
RESIDENTIAL ENERGY EFFICIENCY PROGRAM . . . . . . . . 5
RESIDENTIAL ENERGY EFFICIENCY PROGRAM. . . . . . . . 5
RESIDENTIAL REBATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
WHOLE HOME TIER I INCENTIVE
WHOLE HOME TIER II INCENTIVE
FURNACE INCENTIVES
BOILER- 95%AFUE INCENTIVE
COMBINATION BOILER -95%AFUE INCENTIVE
SMART THERMOSTAT INCENTIVES
STORAGE WATER HEATER INCENTIVE
TANKLESS WATER HEATER
IMPACT VALUE RECOMMENDATIONS . . . . . . . . . . . . . . . .11
Y'
PROGRAM ADMINISTRATION. . . . . . . . . . . . . . . . . . . . . . . .13
ENERGY EFFICIENCY OUTREACH
AND EDUCATION ACTIVITIES . . . . . . . . . . . . . . . . . . . . . . .14
CUSTOMERS
BUILDERS AND THE HOME BUYING COMMUNITY
COMMUNITY
PROCESS EVALUATION
vw COMMERCIAL ENERGY EFFICIENCY PROGRAM . . . . . .22
j COMMERICAL ENERGY EFFICIENCY PROGRAM. . . . . .22
REBATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
CONDENSING UNIT HEATER INCENTIVE
BOILER RESET CONTROL INCENTIVE
HIGH EFFICIENCY CONDENSING BOILER INCENTIVE
FRYER - ENERGY STAR CERTIFIED INCENTIVE
STEAMER- ENERGY STAR CERTIFIED INCENTIVE
GRIDDLE - ENERGY STAR CERTIFIED INCENTIVE
COMMERCIAL PROGRAM OUTREACH,
AWARENESS AND EDUCATION. . . . . . . . . . . . . . . . . . . . . 23
LESSONS - COMMERCIAL PROGRAM
ENERGY EFFICIENCY STAKEHOLDER COMMITTEE. . . .26
SECURING AN ENERGY EFFICIENT FUTURE . . . . . . . . . .26
ENERGY EFFICIENCY: NEXT STEPS . . . . . . . . . . . . . . . . . .28

2023 ANNUAL REPORT 1
EXECUTIVE SUMMARY
The Intermountain Gas Company(Intermountain or Company) Energy Efficiency Portfolio continued to grow in
customer participation in 2023. Together,the Residential Program and the Commercial Program make up the
Energy Efficiency Portfolio.Any Program level discussion or reporting will specify Residential or Commercial
Program.There were 8,496 rebates paid to residential customers, a 6.9%increase over the previous year.
In 2023 the furnace rebate was the most redeemed rebate in the Residential Program with 3,280 rebates,
as it has been since the inception of the program.The smart thermostat was the second most redeemed
rebate by customers for the second year in a row,with 2,830 rebates.There were 1,509 Whole Home Tier
II new construction rebates.The Tankless Water Heater Tier I rebate, and boiler rebate also increased
year over year, but with lower rebate counts than space heating, at 818 and 10 rebates, respectively.
The Commercial Program could not be a more different story.The Commercial Program experienced continued low
participation and awareness despite efforts to grow the program. High-efficiency fryers in the commercial kitchen
equipment category was,once again,the most redeemed commercial rebate at 20 rebates,one more than 2022.
High efficiency condensing boiler rebate had 2 rebates paid,down from a total of 7 the previous year. Contacting
the decision makers or building operators continues to be one of the main challenges of the Commercial Program.
As a portfolio, residential and commercial together,there were 672,417 therms of total claimed savings: 660,919 for
the Residential Program and 11,498 for the Commercial Program. The portfolio was cost-effective with a Utility Cost
Test ratio(UCT)of 1.2.The Residential Program had a UCT of 1.2.The Commercial Program had a UCT of 0.9.
In compliance with Order No. 36245, Intermountain commissioned an Evaluation, Measurement and Verification
(EM&V)study of the Residential Program,which included an impact evaluation and process evaluation.
The impact evaluation resulted in an evaluated savings total of 422,683 for the residential program. Cost-
effectiveness tests conducted with the evaluated savings resulted in a portfolio UCT of 0.8. The Residential
Program UCT was also 0.8 and the Commercial Program UCT remained unchanged,with a UCT of 0.9.
The Company used the results of the impact evaluation to inform Program changes.To heed the recommendation
of Idaho Public Utilities Commission (Commission)Staff comments in Order No.35663, "Staff encourages the
Company to explore other acceptable and vetted bases for deemed savings such as the Regional Technical Forum,"
Intermountain commissioned the development of a technical reference manual (TRM)for the Residential Program.
This TRM is the basis for the proposed Residential Program offerings for 2025,which are outlined in this report.
The process evaluation examined the Company's customer experience;from
how customers first learned about the Program to their level of satisfaction
with services received. Participants and non-participants of the Program were t�
surveyed. Evaluators found staffing and organization sufficient and appropriate
to the design and budget of the Program,as well as found the quality assurance
procedures, management, and implementation tools to be appropriate and
effective. Evaluators provided four recommendations: boost the Program's
marketing and outreach,focus on saving on energy bills and money and
improved comfort as the main motivators for engaging with the Program,
increasing direct-to-contractor outreach, and simplifying the application and
addressing the contractor's belief that the upfront cost of equipment is preventing
energy efficient adoption.Additional details,and the proposed action plan to
Figure 1 SEE Action Energy Efficiency
address these recommendations, is provided in more detail in this report. Program impact Evaluation Guide

2 EXECUTIVE SUMMARY
In addition to EM&V and the cyclic planning-implementation-evaluation process, illustrated in Figure 1,the Company
also commissioned a Conservation Potential Assessment in order to inform the 2023 Integrated Resource Plan
and to identify savings potential for the Energy Efficiency Portfolio.The study results were presented to the
Intermountain Gas Resource Advisory Committee and the full report was filed in Case No. INT-G-23-07. In conjunction
with updating and identifying new savings potential, in accordance with the Order from Case No. INT-G-22-03,
the Company also updated and filed avoided cost calculations as exhibits with the 2023 IRP filing and will "base
cost-effectiveness testing off the avoided costs in place at the time of Program planning."Therefore,the avoided
costs filed in Case No. INT-G-23-07 will be used for the Energy Efficiency Program years 2024 and 2025.
The Company continued to promote the Energy Efficiency Program and energy saving tips to all customers.To focus on
reaching Intermountain customers specifically, in addition to conducting an annual customer engagement activity,the
Company implemented regular, quarterly email communications to customers that have opted in to receiving energy
saving topics.The email campaign provides metrics to gauge the customer engagement by tracking open rates,
click-thru rates, and overall subscribership.The Building Contractor Association (BCA) remains an effective outreach
strategy to raise awareness about energy efficiency with home builders and home building associates,such as HVAC
companies and realtors. Similar to the BCA, membership with the professional organizations American Society of
Heating, Refrigeration and Air-conditioning Engineers(ASHRAE)and the American Institute of Architects of Idaho(AIA)
also served as outreach avenues for the Commercial Program and presented opportunities to connect with architects
and engineers involved in the design process as well as vendors who implement building performance projects.
The Company's collaboration with the Energy Efficiency Stakeholder Committee(EESC) remained a vital
partnership in the advancement of the Energy Efficiency Portfolio.The Company held two meetings in
2023.At the May meeting,the Company provided an overview of year over year, 2021 vs. 2022, rebate
performance and outreach activities.At the fall meeting in November the Company proposed a "meeting
makeover,"to commit to a standardized meeting agenda and increased the meeting frequency to quarterly
meetings instead of twice a year.This is intended to provide more regular Program updates on rebate
performance,outreach activities,the rider balance, administrative updates,and special studies.
Committed to an energy efficient future, Intermountain continued its membership in the North American Gas Heat
Pump Collaborative (Collaborative), and the Energy Solution Center Gas Heat Pump Consortium (Consortium).
Both organizations are focused on the development and adoption of natural gas equipment with efficiencies
over 100%.The Company also participated in the Emerging Technology Program (ETP), a member-driven
collaboration facilitated by GTI Energy,to expand energy saving opportunities for Intermountain customers.
This report details the 2023 Energy Efficiency portfolio performance, cost-effectiveness testing,and
outreach and education activities of the Residential and Commercial Energy Efficiency Programs.

2023 ANNUAL REPORT 3
INTRODUCTION
Intermountain Gas Company,a subsidiary of MDU Resources Group, is a natural gas distribution company serving
over 420,000 residential, commercial, and industrial customers in 75 different communities across Southern Idaho
since 1955.
In addition to reliably providing affordable and safe natural gas for home space and water heating,2023 marked
the sixth year of delivering money and energy saving opportunities through the Energy Efficiency Program at
Intermountain.The Program's mission to secure cost-effective therm savings provides a two-fold benefit to customers.
Individual customers benefit by reducing energy use and realizing long term savings through lower monthly bills by
installing high-efficiency equipment.All customers benefit from the efficient use of natural gas by maximizing today's
assets and delaying the need for expensive system upgrades.
The Residential Program was approved by the Commission and went into effect on October 1, 2017.All customers
receiving natural gas through the Company's residential rate schedule were eligible to participate in the Program.The
Program offers rebates for natural gas equipment meeting specific high-efficiency requirements and can be applied
to replacement equipment,conversions from other fuel sources, and new construction.The Residential Program also
offers rebates for the construction of residential homes that meet specific energy efficiency performance targets.
The Commercial Program was approved by the Commission on March 2021,and went into effect April 1 of the same
year.All customers receiving natural gas through the Company's commercial rate schedule were eligible to participate
in the Program.The Commercial Program offers three space heating rebates and three commercial kitchen
equipment rebates.
To uphold the Company's commitment made in Case No. INT-G-17-03 to file an annual report to document Program
performance,and include a summary of cost-effectiveness, expenditures, participation (number of rebates issued),
and Program implementation methods for each of the incented measures,the Company filed an application request
to designate 2021 energy efficiency expenses as prudently incurred on July 12,2022. On January 13,2023, Order
No.35663 determined 2021 energy efficiency expenses as prudently incurred. On October 6, 2023,the Company
filed an application for an order designating the 2022 energy efficiency expenses as prudently incurred. On June 27,
2024, Order No. 36245 stated the Company's 2022 energy efficiency expenditures were prudently incurred.Although
the Company files an annual report and an application requesting designation of prudent expenses every year,the
time to prepare these reports and receive final orders is a formal process that requires much preparation,analysis,
and consideration by both the Company and the Commission. For that reason, Commission Orders and subsequent
Company actions do not always perfectly align with Program years.Therefore, due to timing, action required to comply
with Orders may take place outside of the reported year.
The Company continues to comply with orders over the evolution of the Program.This report details Program activities,
achievements, and progress made in 2023 as well as changes and updates implemented in 2024 to comply with
Commission Orders.A complete and separate 2024 annual report will be submitted in 2025. Both the Residential and
Commercial Program,which make up the entire Energy Efficiency Portfolio,will be discussed in detail in this report.

4 INTRODUCTION
COST-EFFECTIVENESS TESTING METHODOLOGY
Intermountain's objective is for all rebates to have benefit/cost ratios equal to or greater than one when measured
by the Utility Cost Test.The UCT measures cost-effectiveness from the utility company's perspective and takes
into consideration avoided supply costs, Program administration costs,and incentives paid by the utility. Rebates
undergo cost tests at several stages: preliminary design, implementation,annual review, and during the Evaluation,
Measurement and Verification study(EM&V.)The cost-effectiveness of rebates is also evaluated based on the
customer's perspective using avoided supply costs, Program administration costs, and net participant costs in a test
commonly referred to as the Total Resource Cost Test(TRC.)The TRC is not the primary cost test used for decisions
regarding the inclusion of rebate offerings. In calculating the UCT and TRC, Intermountain relies on the calculations
outlined in the California Standard Practice Manual and the National Action Plan for Energy Efficiency(NAPEE),
Understanding Cost-effectiveness of Energy Efficiency Programs: Best Practices,Technical Methods, and Emerging
Issues for Policy-Makers.
To conduct cost-effectiveness testing for the respective Programs,the Company direct assigned expenses to the
respective Programs. For example,any expense related to residential customer outreach,such as the customer
engagement activity or participation in the Building Contractors Association (BCA)was charged to the Residential
Program expense account. Likewise, all expenses related specifically to the Commercial Program activities, like the
commercial customer survey development,were charged to the commercial expense account.
If an activity or expense related to both the Residential and Commercial Program, Intermountain allocated the
expenses between the Residential and Commercial Programs. For example, professional membership fees to the
Association of Energy Service Professionals,which provided training on topics relevant to general energy efficiency
program management,such as cost-effectiveness, rather than a topic specific to a particular program,were allocated
between the Residential and Commercial Program. The allocation method was applied to other expenses such as
promotional give away items used at both residential and commercial events,equipment cleaning of booth kit items
used at both commercial and residential events,and expenses related to participation in industry groups like GTI
Energy and the Collaborative that address both commercial and residential topics.This expense allocation remained
the same as 2022,shared expenses were split by a 95%allocation to the Residential Program and 5%allocation
to the Commercial Program.The allocation was based on the recorded service starts for the residential and
commercial sector.
Program outreach and education activities for both the Residential and Commercial Energy Efficiency Programs are
contained in this report. For simplicity, Program reporting is separated into two distinct sections, Residential Program
and Commercial Program which will cover Program funding, Program cost-effectiveness, individual measure cost-
effectiveness, as well as Program outreach, awareness,and education for both programs.

2023 ANNUAL REPORT 5
RESIDENTIAL ENERGY
EFFICIENCY PROGRAM
The Residential Energy Efficiency Program is funded by the Energy
Table 1. 2023 Residential Rider Balance
Efficiency Charge(EEC-RS) rider, a monthly per therm charge to
residential customers.As of June 30,2024,the Company had an over- Revenue $ 4,702,205
collected EEC-RS Program balance of$1,919,667. To more accurately Program Expenses
match on-going revenues with expenses,the Company filed to decrease Residential Rebates 2,767,789
the residential EEC rate.On October 1,2024, Idaho Public Utilities Labor 642,719
Commission issued Order No.36337 and the EEC was reduced from Program Delivery 43,242
$0.01564 per therm to$0.01149 per therm.The Company will continue Special Studies 218,747
to monitor fluctuations in the rider balance to keep rates as stable as Market Transformation 23,750
possible and avoid excessive over or under collections balances. Table Direct Expenses 77,792
1 provides detailed information on the 2023 Rider balance at December Total Program Expenses 3,774,039
31, 2023.
2023 Rider Deferral
Over/(Under)Collection 928,162
RESIDENTIAL ENERGY
Prior Year Rider Balance
EFFICIENCY PROGRAM Over/(Under)Collection 450,521
On June 17, 2024, Idaho Public Utilities Commission issued Order No.
Rider Account Balance
36425 requiring that"the Company's next prudency filing shall include
an EM&V with a billing analysis covering Whole Home Tier I,Whole Over/(Under)Collection $ 1,378,687
Home Tier II, Furnace and Smart Thermostat measures."To comply
with the Order, Intermountain contracted with a third-party evaluator
(Evaluator)to perform an impact evaluation of these measures and conducted the first evaluation of all water heating
measures: boiler, combination boiler,storage water heater and tankless water heater.
Evaluators conducted a billing analysis on the measures identified in the Order.A second evaluation methodology
was also used to evaluate Intermountain in a way that is consistent with the evaluation methodologies employed by
other Idaho utilities.This method used the Regional Technical Forum (RTF)and Illinois Technical Reference Manual (IL
TRIM) in a deemed savings methodology.This analysis evaluated the Intermountain Program using the deemed savings
from the RTF and IL TRIM workbooks. Evaluators compared these results to the billing analysis approach. Ultimately,
the Evaluators recommended that"Intermountain Gas align evaluation methods with the utilities present in Idaho,"
to"allow for programs to be evaluated and compared across utilities with the same measuring stick with results that
are supported through peer reviewed and approved documentation"' For each measure, Evaluators recommended
Intermountain evaluate the program using the RTF or IL TRM 12.0.The complete impact evaluation report is provided in
Supplement 1: Impact Evaluation Report.
This report will refer to both claimed savings and evaluated savings. Claimed savings are based on the therm saving
estimates the Company used at the time of program planning. Evaluated savings are the savings determined by the
Evaluators from the 2024 EM&V study.
1 Supplement 1:Impact Evaluation Report,Section 5.1 Rebate-Level Findings and Recommendations

6 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
In order to inform program planning and use the evaluation study to identify improvements and enhancements to
program design,the evaluated savings from the EM&V report were used for cost-effectiveness testing for the 2023
program year.This report outlines, by measure,the claimed savings,the evaluated savings,and cost-effectiveness
testing using evaluated savings for the 2023 Residential Program.
Once the evaluation was complete,the Company turned to program planning and again sought to ensure the Program
is in line with other Idaho utilities.The Company revisited Staff notes from Order No.35663, "Staff encourages the
Company to explore other acceptable and vetted bases for deemed savings such as the Regional Technical Forum"To
put this recommendation into practice, Intermountain commissioned the Evaluators to develop a Technical Reference
Manual (IGC TRM)for the Intermountain Energy Efficiency Program. The IGC TRM was based on the RTF gas measures.
For measures not found in the RTF, Evaluators used the IL TRM. Current relevant research, recent impact evaluations,
and Technical Reference Manuals developed for other states and/or regions are referenced in the IGC TRM where
appropriate. Evaluators also incorporated into the IGC TRM billing analysis of natural gas heated homes participating in
HVAC rebates between April 2021 and December 2023 to support savings reductions and to estimate equivalent full
load heating hours.
The IGC TRM provides unit energy savings(UES or deemed savings)estimates of therms for the residential measures.
The selection of measures for the IGC TRM was based on the following: rebate performance history planned
incorporation of measures in the upcoming Program year,and an assessment of whether a measure is an appropriate
candidate for deemed savings.The manual is "intended to facilitate the cost-effectiveness screening, planning,
tracking,and energy savings reporting for the Residential Program. It is a living document in which the stipulated
values are revised according to relevant industry research and impact evaluation findings."The complete IGC TRM is
provided in Supplement 2: IGC TRM V. 1.0 Manual.2
The Company then used the IGC TRM to redesign the residential rebate offerings. For each rebate,the IGC TRM was
used to update the following inputs: efficiency requirements,savings estimates, estimated useful life, and incremental
costs.The Company then used the updated measure inputs,the 2023 Integrated Resource Plan (IRP)avoided costs,
forecasted rebate participation, and forecasted 2025 budget,to conduct cost-effectiveness testing and set incentive
amounts for each rebate.
It is important to note that based on Order No.35663,the Company is to base program planning off the most recent
IRP filing and to base cost-effectiveness testing off the avoided costs in place at the time of program planning.The
program updates outlined in this report were performed using the avoided costs from the 2023 IRP.The 2023 IRP
avoided costs increased from the 2021 IRP avoided costs and,as a result,the incentive amount for the furnace
measure will remain the same,the smart thermostat incentive will decreas and all other incentive amounts will increase
in the 2025 Program update.
The following section outlines the claimed savings,the evaluated savings, cost-effectiveness based on evaluated
savings,evaluator recommendations, and the updated rebate based on the IGC TRM and 2023 IRP avoided costs for
each measure.
2 Supplement 2:IGC TRM V.1.0 Manual p.3

2023 ANNUAL REPORT 7
RESIDENTIAL REBATES
Whole Home Tier I Incentive
The Whole Home Tier I incentive provided residential customers a $900 rebate for new construction homes that met
the following criteria:
• HERS rated
• Air sealing at or below 3 ACH at 50 Pa
• Ceiling insulation at or above R-49
• Ducts and air handler located inside conditioned space or duct leakage to outside of less than 4 CFM25/100 ft2 CFA
• Furnace efficiency at or above 97%AFUE
The Company received 2 qualifying applications for this incentive during the 2023 Program Year and Intermountain
claimed annual savings of 322 therms.The 2024 impact evaluation resulted in 183 therms per unit, or 367 annual
therm savings. Based on the evaluated savings,the incentive was cost-effective under the UCT analysis,with a benefit-
to-cost ratio of 1.4. The TRC ratio was 0.6.
Whole Home Tier II Incentive
The Whole Home Tier II incentive provided residential customers a $700 rebate for new construction homes that met
the following criteria:
• HERS rated
• Air sealing at or below 4 ACH at 50 Pa
• Ducts and air handler located inside conditioned space or duct leakage to outside of less than 4 CFM25/100 ft2 CFA
• Furnace efficiency at or above 95%AFUE
There were 1,509 Whole Home Tier II rebates paid. Intermountain claimed annual savings of 193,152 therms.The 2024
impact evaluation reported savings of 110 therms per unit, or 165,990 therms attributable to the Whole Home Tier II
rebate. The evaluated savings were cost-effective under the UCT analysis with a benefit-to-cost ratio of 1.1.The TRC
ratio was 0.4.
Recommendation: Evaluators compared the HERS rater modeling files to a User Defined Reference Home (UDRH)
specific to Idaho's residential building code requirements and found this approach was in alignment with the Regional
Technical Forum New Homes Protocol as well as the evaluation method used by other Idaho utilities.
Program changes: Based on the IGC TRM that was informed by the 2024 evaluation,the Whole Home rebate as
designed was found to be in line with the RTF New Homes Protocol. There are no changes to the minimum efficiency
requirements.All other measure inputs were updated to be in accordance with the IGC TRM workbook and the
increased incentive was cost-tested using 2023 IRP avoided costs.A comparison of the 2023 Program and proposed
changes to the 2025 Whole Home Tier I and Tier II rebates are outlined in Tables 2 and 3.
Table 2.Whole Home Tier I Incentive Changes Table 3.Whole Home Tier II Incentive Changes
Measure Inputs 2023 Program 2025 Program Update Measure Inputs 2023 Program 2025 Program Update
Efficiency Energy Performance Targets Energy Performance Targets Efficiency Energy Performance Targets Energy Performance Targets
Requirements with 97%AFUE furnace with 97%AFUE furnace' Requirements with 97%AFUE furnace with 97%AFUE furnace'
Therm Savings 161 183 Therm Savings 128 110
Estimate Estimate
EUL(yrs.) 25 22 EUL(yrs.) 25 22
Incremental Cost $2,117 $3,068 Incremental Cost $2,117 $2,941
Incentive Amount $900 $1,500 Incentive Amount $700 $1,000
'no change 'no change

8 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
Furnace Incentive
The furnace incentive provided residential customers a $350 rebate for the installation of a high-efficient natural gas
furnace with a minimum efficiency rating of 95%AFUE.A total of 3,280 furnace rebates were issued by the Company,
an increase compared to 3,148 rebates the previous year. Intermountain claimed annual savings of 285,360 therms.
The 2024 impact evaluation reported savings of 44 therms per unit, or 145,697 therms attributable to the Furnace
rebate. The evaluated savings under the UCT analysis resulted in a benefit-to-cost ratio of 0.6. The TRC was 0.2.
Recommendation: Evaluators recommend utilizing RTF Gas Furnace workbook UES for claimed savings
moving forward.
Program changes: Based on the IGC TRM that was informed by the 2024 evaluation,there are no changes to the
minimum efficiency requirements.All other measure inputs were updated to be in accordance with the IGC TRM
workbook. Based on cost-testing using 2023 IRP avoided costs the$350 incentive amount remains unchanged.A
comparison of the 2023 Furnace rebate and proposed changes to the 2025 furnace rebate is outlined in Table 4.
To inform the TRM,evaluators used the 2022-2023 Intermountain population tracking data to analyze participation
by heating zone and by furnace efficiency, 95%AFUE or greater and
97%AFUE or greater.The evaluators provided a UES for the 95% Table 4.Furnace Incentive Changes
AFUE furnace, and the 97%AFUE furnace,45 therms and 56 therms, 2025 Program
respectively.A blended UES of 46 therms was also calculated based on Measure Inputs 2023 Program Update
Efficiency 95%AFUE or 95%AFUE or
the historical data of rebated furnaces from the population tracking data. Requirements greater greater*
To keep things simple for Intermountain customers, rather than offer Therm Savings
0 o Estimate 87 46
two different furnace rebates, 95/o AFUE or greater and 97/o AFUE or
greater,the proposed 2025 Program update uses the blended UES of EUL(yrs.) 20 22
46 therms and will continue to use 95%AFUE as the minimum efficiency Incremental Cost $1,307 $278
requirement for the furnace rebate.A comparison of the 2023 Program Incentive Amount $350 $350*
'no and proposed changes to the 2025 furnace rebate is outlined in Table 4. change
Boiler — 95%AFUE Incentive
The boiler incentive provided residential customers an $800 rebate for the installation of a high-efficient boiler with a
minimum efficiency rating of 95%AFUE.There were 10 rebates issued in 2023 compared to 5 in 2022. Intermountain
claimed annual savings of 1,590 therms.The 2024 impact evaluation reported savings of 103 therms per unit, or 1,030
therms attributable to the Boiler rebate.The evaluated savings under the UCT analysis resulted in a benefit-to-cost
ratio of 0.9.The TRC was 0.6.
Recommendation: Evaluators recommended utilizing the Illinois Technical Table 5.Boiler Incentive Changes
2025 Program
Reference Manual boiler UES for claimed savings moving forward. Measure Inputs 2023 Program Update
Efficiency 95%AFUE or 95%AFUE or
Program changes: Based on the IGC TRM that was informed by the 2024 Requirements greater greater*
evaluation,there are no changes to the minimum efficiency requirements. Therm Savings 159 107
All other measure inputs were updated to be in accordance with the IGC Estimate
TRM workbook,and a UES of 107 therms will be used. Based on cost- EUL(yrs.) 25 25*
testing using 2023 IRP avoided costs the incentive amount will increase Incremental Cost $1,166 $2,135
from $800 to$1,000.A comparison of the 2023 Program and proposed Incentive Amount $800 $1,000
'no changes to the 2025 boiler rebate is outlined in Table 5. change
Combination Boiler — 95%AFUE Incentive
The combination boiler incentive provided residential customers an $800 rebate for the installation of a high-efficient
combination boiler with a minimum efficiency rating of 95%AFUE.There were 7 rebates issued in 2023 compared
to 6 in 2022. Intermountain claimed annual savings of 1,085 therms.The 2024 impact evaluation reported savings of

2023 ANNUAL REPORT 9
168 therms per unit,or 1,176 therms attributable to the Combination Boiler rebate in 2023.The evaluated savings were
cost-effective under the UCT analysis with a benefit-to-cost ratio of 1.3.The TRC was 0.3.
Recommendation: Evaluators recommend utilizing the Illinois Technical
Reference Manual V12.0 UES for the combination boiler claimed savings Table 6.Combination Boiler Incentive Changes
2025 Program
moving forward. Measure Inputs 2023 Program Update
Program changes: Based on the IGC TRM that was informed b the Efficiency 95%AFUE or 95%AFUE or
9 9 y Requirements greater greater*
2024 evaluation,there are no changes to the minimum efficiency Therm Savings
155 168
requirements.All other measure inputs were updated to be in
Estimate
accordance with the IGC TRM workbook. Based on cost-testing using EUL(yrs.) 22 25
2023 IRP avoided costs the incentive amount will increase from $800 to Incremental Cost $3,522 $2,412
$1,500.A comparison of the 2023 rebate and proposed changes to the Incentive Amount $800 $1,500
2025 combination boiler rebate is outlined in Table 6. no change
Smart Thermostat Incentive
The smart thermostat incentive provided residential customers up to a $100 rebate for the installation of an Energy Star
Certified thermostat. Program Terms and Conditions do not allow for incentive payments to exceed the amount paid for
equipment. In 2023 a total of 2,830 thermostat rebates were issued by the Company, an increase compared to 2,769
rebates the previous year. Intermountain claimed annual savings of 124,520 therms for this measure.The 2024 impact
evaluation reported savings of 21 therms per unit, or 59,090 therms attributable to the Smart Thermostat rebate. The
evaluated savings under the UCT analysis resulted in a benefit-to-cost ratio of 0.4.The TRC was 0.3.
Recommendation: Evaluators recommend utilizing RTF Gas Furnace workbook UES for claimed savings
moving forward.
Program changes: Based on the IGC TRM that was informed by the 2024 evaluation,several additional requirements
will be added to the Energy Star Certified requirement in the proposed 2025 offering:the thermostat must have a
learning based schedule, must be wi-fi enabled, must include on-board motion
occupancy, must have automatic HVAC reduction when home
is unoccupied, and it must replace a non-qualifying thermostat. Table 7.Smart Thermostat Incentive Changes
Due to the additional requirements for the smart thermostat from 2023 2025 Program
the RTF workbook, a UES of 26 therms will be used for the 2025 Measure Inputs Program Update
program update, rather than the evaluated savings of 21 therms. Efficiency Energy Star Energy Star Certified with
Requirements Certified additional requirements
Based on cost-testing using 2023 IRP avoided costs the $100
Therm Savings 44 26
incentive amount will be reduced to$50.These updated inputs also Estimate
address Order No.36245 which required the Company to provide EUL(yrs.) 11 7
justified and estimated useful life(EUL)for the thermostat measure. Incremental Cost $208 $165
A comparison of the 2023 Program and changes to the proposed Incentive Amount $100 $50
2025 smart thermostat rebate is outlined in Table 7.
Storage Water Heater Incentive
The storage water heater incentive provided residential customers a $115 rebate for the installation of storage water
heater with a minimum efficiency rating of 0.68 UEF.A total of 30 water heater rebates were issued by the Company,
compared to 32 rebates the previous year. Intermountain claimed annual savings of 1,140 therms.The Company did not
differentiate the water heater incentive by tank size. In order to evaluate savings, rebated water heaters were sorted by
tank size: greater than 55 gallons and equal to or less than 55 gallons.The 2024 impact evaluation reported savings
of 25 therms per unit for water heaters equal to or less than 55 gallons, and 2 therms for water heaters with tank size
greater than 55 gallons.This 55+gallon size storage water heater resulted in low savings due to the fact that the

10 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
federal standard for these storage water heaters is more stringent than for storage water heaters in the less than 55
gallon size category.Together,the evaluated savings for storage water heaters was 525 therms.The evaluated savings
under the UCT analysis resulted in a benefit-to-cost ratio of 0.5.The TRC was 0.2.
Recommendation: Evaluators recommend utilizing RTF water heater workbook UES for claimed savings
moving forward.
Program changes: Based on the IGC TRM that was informed by the 2024 evaluation,the incentive requirements
should be specifically for condensing storage water heaters based on Energy Star Qualified Version 4.0 or Version
5.0,which would translate to a minimum efficiency of 0.81 UEF.The
current offering with a minimum efficiency of 0.68 UEF and a $115 Table 8.Storage Water Heater Incentive Changes
incentive experienced low participation;30 rebates in 2023 and 32 2023 2025 Program
rebates in 2022. Based on cost-testing using 2023 IRP avoided costs Measure Inputs Program DO NOT OFFER
the maximum incentive would be$200.The Company anticipates that Efficiency 0.68 UEF Energy Star Qualified V.5
Requirements (UEF of 0.81 or greater)
due to the significant increase in the efficiency requirement and minimal
Therm Savings 38 34
increase in the incentive,from $115 to$200,this incentive will continue Estimate
to underperform,and plans to retire this offering.A comparison of the EUL(yrs.) 13 15
existing measure requirements and updated requirements are provided Incremental Cost $390 $1,808
In Table 8. Incentive Amount $115 $200
Tankless Water Heater Incentive
The Tankless Water Heater Tier I incentive provided residential customers a $325 rebate for the installation of a
condensing tankless water heater with a minimum efficiency of 0.91 UEF.There were 818 rebates paid in 2023,
compared to 570 incentives paid in 2022, and the Company claimed 53,170 therms.The 2024 impact evaluation
reported savings of 59 therms per unit, resulting in 48,295 therms of evaluated savings.The evaluated savings were
cost-effective under the UCT analysis with a benefit-to-cost ratio of 1.0.The TRC was 0.2.
The Tankless Water Heater Tier II incentive provided residential customers a $300 rebate for the installation of a
condensing water heater with a minimum efficiency of 0.87 UEF.There were 10 rebates paid in 2023 and claimed
savings of 580 therms.The 2024 impact evaluation reported savings of 48 therms for the Tier II tankless water heater,
or a total of 476 therms attributable to the rebate.The evaluated savings under the UCT analysis resulted in benefit-to-
cost ratio of 0.9.The TRC was 0.3.
Recommendation: Evaluators recommend utilizing RTF water heating workbook UES for claimed savings
moving forward.
Program changes: Based on the IGC TRM that was informed by the 2024 evaluation,the tankless water heater
incentive should be based on Energy Star Qualified and non-Energy Star Qualified tankless water heaters, rather than
the simple minimum efficiency requirement for the current incentive.
Historically,the Tier 11 Tankless Water Heater incentive,which requires a lower minimum efficiency, has experienced
very low uptake,10 rebates in 2023 and 15 rebates in 2022. Evaluators recommended offering a tiered tankless water
heater offering based on ENERGY STAR and Non-ENERGY STAR certified requirements. Since the Non-ENERGY
STAR requirement is essentially the same as the current Tankless Tier II incentive, a 0.87 UEF,the Company will only
offer incentives for ENERGY STAR Version 5.0 tankless water heaters.This will simplify this offering by leveraging the
expertise and brand awareness of Energy Star Certified products and the online resource,the Energy Star Certified
products finder. Based on cost-testing using 2023 IRP avoided costs the incentive amount for will be $400 for the
ENERGY STAR qualified water heater.

2023 ANNUAL REPORT 11
The Company will offer a single ENERGY STAR qualified tankless water heater rebate and will retire the Tier II Tankless
Water Heater. Because the 2025 Program update does change the requirements for the Tier I tankless water heater,a
savings estimate of 51 UES will be used instead of the 59 UES of evaluated savings from the study based on the 2023
program requirements.A comparison of the 2023 Program and proposed changes to the 2025 rebate is outlined in
Tables 9 and 10.
Table 9.Tankless Water Heater Tier I Incentive Changes Table 10.Tankless Water Heater Tier II Incentive Changes
TANKILESS WATER TANKLESS WATER TANKLESS WATER TANKILESS WATER
HEATER TIER I HEATER ENERGY STAR HEATER TIER 11 HEATER ENERGY STAR
Measure Inputs 2023 Program 2025 Program Update Measure Inputs 2023 Program 2025 Program Update
DO NOT OFFER
Efficiency Requirements 0.91 UEF ENERGY STAR Efficiency Requirements 0.87 UEF Meets Federal
Certified Minimum Standards
Therm Savings Estimate 65 51 Therm Savings Estimate 58 36
EUL(yrs.) 25 20 EUL(yrs.) 25 20
Incremental Cost $1,800 $895 Incremental Cost $1,152 $260
Incentive Amount $325 $400 Incentive Amount $300 $250
IMPACT EVALUATION RECOMMENDATIONS
In addition to the evaluation of savings,the Evaluators provided recommendations by measure.These
recommendations are outlined in the full report.3 This section provides a summary of recommendations by measure,
and the Company's response to each recommendation.There was one overarching recommendation which was
repeated for each measure,the below excerpt is about furnaces, but the recommendation also applied to Whole
Home,tankless water heaters, and smart thermostats:
The Evaluators recommend that Intermountain Gas align evaluation methods with the utilities present in Idaho
with gas furnace measures.This allows for programs to be evaluated and compared across utilities with the
same measuring stick with results that are supported through peer reviewed and approved documentation.
Therefore,the Evaluators recommend that Intermountain Gas evaluate their natural gas furnace rebates using
the RTF Gas Furnace UES Workbook.4
In the case where the measure was not a work product of the RTF workbook, specifically boilers and combination
boilers, Evaluators recommended using the Illinois TRM V12.0,with RTF inputs. Going forward,the Company will be in
alignment with these recommendations since 2025 program planning will be based on the IGC TRM,which is based
on the RTF, or IL TRM with RTF inputs, and the future savings will be evaluated based on the IGC TRM,allowing the
Program to be evaluated and compared across utilities with the same measuring stick. The following outlines additional
recommendations for each measure.
Whole Home
Recommendation:The Evaluators recommend Intermountain staff thoroughly review the model efficiencies in the
applications before dispersing incentives to the customers, and more clearly communicate the tiered requirements.
This recommendation stems from the fact one of the Whole Home Tier I rebates paid in this evaluation period did not
meet the minimum AFUE requirement of the incentive.A Tier I rebate was paid for a home with a 96.5%AFUE furnace
installed, instead of the required 97%AFUE furnace,all other energy performance targets were met for the rebate in
question. Upon further review of this error,the Company determined that the error was made when all rebate tracking
was being recorded in an Excel spreadsheet and was due to erroneously recording the furnace model and AFUE
information on the wrong line of the spreadsheet prior to payout.
3 Supplement 1:Impact Evaluation Report,p.57
4 Ibid.p.58

12 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
Action:When the Company implemented ERA for rebate processing and recording,the excel spreadsheet previously
used for processing was retired, eliminating the possibility of this error being repeated in the future.
Smart Thermostat:
Recommendations:
• Although the current rebate application already asks the customer to define the previous thermostat type,the
Evaluators recommend Intermountain clarify the question currently posed to improve clarity. If the replaced
thermostat also meets RTF qualifications,the project does not qualify for claimed savings.
• The Evaluators recommend that Intermountain require the rebated product to be RTF-qualified before applying
incentive,verify qualification before providing incentive for rebates and document model number,and document
qualification in database.With this method, only products that meet the RTF specifications of a connected
thermostat may receive savings through the RTF workbook.
Action:These recommendations for the smart thermostat are most applicable to the smart thermostat incentive
going forward. In order to meet the requirements of the IGC TRM,the Company will plan to clarify the efficiency of
the previous equipment and will not rebate thermostats that are replacing the same efficiency as the incentivized
thermostat. Previously,the only requirement for the smart thermostat rebate was ENERGY STAR certification. To meet
the Evaluators recommendation,and based on IGC TRM guidance,the Company will verify smart thermostats meet 6
of the 7 additional requirements before providing incentive rebates, one condition applies to electric resistant heat and
therefore is not applicable to gas savings.
Tankless Water Heater
Recommendation:
• The Evaluators recommend that Intermountain update storage tank water heater program requirements to require
the equipment is ENERGY STAR certified.With this requirement, efficient equipment will qualify for RTF savings
even though the ENERGY STAR requirements themselves are updated.
• The Evaluators recommend that Intermountain remove Tier II incentives. Participation for this measure is reduced;
therefore, continuing incentives for the Tier I, or higher efficiency equipment,will encourage customers to follow the
natural market shift that is already occurring.
• The Evaluators also recommend Intermountain consider offering tiered incentives for ENERGY STAR-qualified and
non-ENERGY STAR-qualified tankless water heaters to account for differing savings estimates.
Action:The Company will update the tankless water heater incentive to require ENERGY STAR certification,which is
also in line with the IGC TRM. Intermountain will remove the Tier II Tankless incentive at 0.87 UEF and will retire this
lower efficiency tier of the tankless water heater offering to encourage customers to follow the natural market shift to
higher efficiency.Although Evaluators recommend a tiered tankless offering based on ENERGY STAR vs. Non-ENERGY
STAR certified, rather than by minimum efficiency,the Company does not plan to offer an incentive for Non-ENERGY
STAR certified tankless water heaters.The Company will instead leverage the expertise and brand awareness of
ENERGY STAR, as well as the ENERGY STAR product finder to simplify things for the customer.

2023 ANNUAL REPORT 13
PROGRAM ADMINISTRATION
In 2023 the Company participated in a major project to develop a rebate processing application (rebate app). Rather
than purchase a third-party product with a potentially expensive and likely on-going subscription use fee,the Company
worked with its in-house Enterprise Information Technology(EIT)department to develop a rebate app, called the
Enterprise Rebate App(ERA.)This user interface allows the Company to validate customers within the application,
eliminating the need to switch between applications to validate customer information. ERA functionality also builds
and maintains customized libraries of equipment brands and models,efficiencies, builders,contractors, and home
raters which are frequently seen by the Company,eliminating repetitive data entry and opportunities for data entry
errors.The customized equipment library allows for the efficiency of models to be collected, and to designate
whether a model is approved for the rebate, reducing the possibility that a rebate will be paid out for non-qualifying
equipment. To eliminate the need for labor-consuming data entry, ERA was also designed to accept batch imports from
builders applying for multiple rebates at one time.With the utilization of application programming interfaces(API) new
construction rebates can be imported directly into ERA. Static data inputs that change infrequently and need minimal
updates,were incorporated in the system. Since account coding and rebate amounts are embedded in ERA coding,
rebates cannot be assigned to the wrong workorder(furnace rebate charged to the workorder for water heaters)
and rules out a rebate being paid for the incorrect amount(furnace paid as$300 instead of the correct amount of
$350.)While these types of errors pre-ERA implementation were few,the Company remains steadfast in its effort to
adhere to Commission directives to maintain internal controls and catch redundancies and inefficiencies. ERA aids in
both of these efforts.The record keeping of rebate payments and storage of support documents, such as the rebate
application, invoices, pictures, and notes is also captured within ERA.
Once rebate applications are entered and validated in ERA,this application streamlines payment approval and
payment processing.Approved rebate payments are submitted automatically by the system overnight to be processed
by accounts payable,eliminating the manual process of creating individual payment requests and the need for
uploading records to multiple systems.This newly automated process has allowed for the greatest efficiency gains.
ERA phase I,which primarily focused on the back-office process of the rebate app,was completed in 2023.The
Company started working on Phase II of ERA in late 2023 to develop a customer facing component(customer
webapp.)This customer webapp will enable customers to apply for rebates from their online customer account,
eliminating two manual processes: customer validation,this is accomplished by the customer signing-in to their unique
customer account,and data entry,since customers enter all rebate information and upload supporting documents
into the customer webapp.The online rebate application also switched from a 3rd party form software to an in-house
software application further securing transmission of sensitive customer information. Customer webapp applications
will be imported into the back-office process of the rebate app,further reducing the number of applications that require
manual data entry.Though the customer webapp removes the need to enter the data into ERA, all rebates, regardless
of the method they are submitted,still undergo manual review to ensure proper support documents were received and
eligibility requirements are met.
Select customer webapp information will also be available to the customer experience team (CXT).When customers
call the Company with simple questions about their rebate application, such as rebate payment status or confirmation
of receipt of the application, CXT agents will be able to look up customer rebates and view basic information.This
reduces the need for the CXT to transfer calls or messages to the energy efficiency department regarding these
customer inquiries, and ultimately reduces the number of call backs required by the EE department.This provides for a
better customer experience and saves time for all:the customer, CXT agents and EE Department team members.The
Company will "continuously explore ways to reduce labor costs," as directed by the Commission.

14 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
ENERGY EFFICIENCY OUTREACH AND
EDUCATION ACTIVITIES
The Company continued its efforts to promote the Program's incentives wsaviingea e' 11641 n p_.�_
and energy saving resources among residential customers using both �' - -
established methods and new avenues of outreach in 2023.This included
methods of customer communication from the Company as well as using
lanes of communication outside the company to reach customers digitally,
through printed publications, and in person at community events.
ies .msm amuc INRRM9UMAIN'
..iW(a,.n witM1^g,. A_ __ O Effld—y
Customers
As in previous years, Program information was provided to each new , 4
residential customer that starts service with Intermountain. Customers
receive a new customer letter in the mail that contains information about how
to manage their gas service,as well as an Energy Efficiency bill insert that .
lists available rebates.The front and back of this bill insert can be seen in n:^ wv�ovo©o ®`=a.�,m,_. ., °EPA
Figure 2. In 2023,there were 30,408 new customer letters sent containing
EE program brochures. Figure 2 Residential Program Brochure
The Company provided regular, quarterly energy efficiency
Table 11.Customer Email Metrics
themed communications to customers that opt in to receiving
energy efficiency messages.These communications promoted EMAILS SENT TO RESIDENTIAL CLISOMTERS
available rebates, energy savings tips and directed customers to Date Number Sent Open Rate CTR
resources that are available on the Program website.To measure Q1 Feb.14 207,283 57% 1%
the effectiveness of these communications the Company 02 May 23 200,870 61% 3%
tracked data related to the performance of each email such as Q3 Aug.29 218,957 46% 3%
the number of emails sent,open rates, and click-through rates Q3 Nov.28 210,166 59% 22%
(CTR)for links provided in the email. It is important to note that
EE emails are only sent to customers that opt-in to receiving notifications from the EE department.These results are
provided in Table 11.
The company saw the highest rate of interaction among residential customers with the 04 email,which generated
a 22%click rate.This created a spike in the Appliance Rebate page traffic for the month of November, as seen here
in Table 12.The Program also noticed a spike in web traffic in May on the Energy Savings Calculator page when the
quarterly email highlighted this tool, as seen in Table 13. Higher click rates and web traffic are likely due to targeted
content of the email based on time of year,specific rebates and tools available on the website, and experimenting with
different subject lines that more effectively hook the reader's attention.
Appliance Rebate Web Page Visitors by Month Savings Calculator Web Page Visitors By Month
6000 700
.� 5000 `0 600
> > 500
m 4000 m
a a 400
y 3000 v
>i 3 300
0 2000 `o
w v 200
a a
1000 ES0D
Z Z
0 0 —
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month Month
Table 12 Energy Efficiency Appliance Page Web Page Visits Table 13 Savings Calculator Web Page Visits

2023 ANNUAL REPORT 15
The Company also continued to promote energy efficiency tips, updates about - Intermountain Gas Company "'
Program activities, and available rebates over multiple social media platforms Hgs the cold weather persists,please never attempt
including Facebook, Instagram,X(formerly Twitter),and Linkedln.These to heat your home with outdoor propane heaters or by
using your range as a heater.Find many low-to no-cost
monthly posts were also used to celebrate certain holidays and participate in measures you can take to make your home more
energy efficient and help energy costs at our webpage,
other social media drives/events celebrating energy efficiency awareness such https:#buff.ly/3EK4fZW
as Earth Day and Energy Star Day.An example of a monthly post can be seen in WINTERTIPS
Figure 3.
INTER
Energy Efficiency conducted a month-long annual customer campaign to raise h
awareness and promote energy efficiency education in August.The 2023, "Easy
Savings Kit" campaign focused on raising awareness about easy, low-cost,
energy saving actions for the home. For this customer engagement activity,
the Company hosted a sweepstakes giveaway of 100 Energy Saving Kits.The
kits contained do-it-yourself home weatherization products such as window .,
film insulation, rope caulk,and foam weatherstripping along with an instruction INTERMOUNTAIN
I CAS COMPANY
sheet explaining how to install the products included in the kit.The theme of
easy savings was combined with an easy entry form. Customers were required
to complete an entry form with their name and contact information. Figure 3 Energy Efficiency Social
Media Post
The Easy Saving Kit promotion was mailed as a bill insert to all customers
either by traditional snail mail or provided as a digital bill insert to customers
receiving e-bills This bill insert can be seen in Figure 4.Along with the bill
insert,the Company sent 218,957 emails to customers who opted in to receive
Intermountain EE email updates and promoted the sweepstakes via social
media. The sweepstakes generated 5,570 entries.While the campaign raises ENERGY
awareness about low-cost ways to save energy at home, participation in the FOR YOUR O
ME
sweepstakes was likely dependent on customers attitudes about doing a Do-it-
Visit the fink below or scan the code to enter to win 1 of 100
yourself project, living in a newer home that doesn't require weatherizing, or not Easy Savings Kits containing these items:
10pa<k of each,outlet and switch foam gasket
needing a kit if the home had already been weatherized. s �#r
17'roll of closed cell foamtape weatherstripping
17'roll of V seal type weatherstrl pping
30'ro11 of rope caulk ram.
Wl ndow kit ❑E W
Following the distribution of the kits to the winning customers,the Company -intgas.com/easy_savings_kit
surveyed the kit recipients about their experience installing their products. SMARTTHERMOSTAT AIR SEALING
The survey yielded a 12% response rate from the 100 winners that were sent
the survey.When asked to rate their overall satisfaction with the survey entry
process based on a 5-point scale,survey respondents on average rated their
Forgetthe hassle ofadjusting your Air leaks waste your energy dollars!
overall satisfaction with the application process a 4.33 out of 5. The survey �h " fi,,art Find E,agygdVa step by step guide
was also helpful in learning about which products were more likely to be when you buy air ENERGY STAR
Certified'mart thermostat
utilized than others.All survey respondents indicated they installed the foam
tape weatherstripping from the kit and 91% indicated they installed the V VENTILATION ENERGY EFFICIENT
seal weatherstripping.Alternately,the window film insulation had the lowest r, o
installation rate among survey respondents with about 66%indicating they ► I I
installed the product.The survey also included an option to provide open-ended
Fresh Stairs trap dwst from entering Wt,0h,ating mak,;,irp 14 1 M)l
feedback. One respondent expressed their gratitude in the following statement:
f,.h air filtairshalpysu,heating he it,
"The v-seal was a life saver to seal a gap in our sliding glass door. I hadn't system ruil more efficiently.
done anything about it because I wasn't sure what to get. Having a variety of
products in hand was great. I also used the foam strips to seal the windows
in the room.It made a huge difference... I was so grateful I had that kit!"
BOISE&TREASURE VALLEY 208-377-6840-ALL OTHER AREAS 8M548-3679
The Company uses a number of metrics in an attempt to measure the
effectiveness of the customer engagement activity,such as sweepstakes Figure 4 Easy Savings Bill Insert

16 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
entries,web page visits,and ultimately rebate performance. In September immediately following the customer
engagement activity,the Company had an increase in the number of rebates submitted that indicated the bill insert
as their source of program awareness.This information is collected on the rebate application asking the rebate
applicant"How did you hear about the program."There was also another increase in December,which could be a
delayed response to customers learning about the program in the August insert, installing equipment and applying in
December.A summary of the responses to this question on the rebate application is shown in Table 14.
The Company will explore annual customer engagement topics and activities to raise awareness about energy saving
opportunities and available rebates.
Table 14. "How did you hear about the Program" Responses
2023 Program Referral Responses
175 SIII Insert
Cpm Ity Event
Direct wn
Energy Rater
,In
IOC Employee
•Spclal McEle
•ftb,ne
Iss
Ina
75
so
Jen feb Mai Ape May Jun Jul Aug Sep -1 Nov Dec
M v program
roragz3
showing 55 of 55 Cata points
Builders and the home buying community
With the easiest time to implement EE measures being at the time of construction,the Company continued efforts
to bring messaging to home builders and the home buying community. Partnerships with local and state Building
Contractor Associations (BCA)throughout the service territory continued to be a preferred method of communicating
with builders throughout the year.The Company conducted outreach by sponsoring BCA events such as the Parade
of Homes(POH),associate showcase and builder expos, and annual golf
tournaments as well as other opportunities such as membership and associate's
council meetings and board of directors' meetings for the statewide BCA. Your dream hcme.
moose rommn.moose anorbal.rty.choose energy erf Keac aal�,.
Natural Gas.The choice is clear.
Intermountain placed an energy efficiency themed full-page ad in each POH
magazine with each of the 5 BCA's.An example of this ad is shown in Figure 5.
These magazines are distributed throughout the respective association regions.
By placing an ad in these magazines,visitors who view the ad get information �r�l
on the Company and energy efficient homes while they are looking at examples
of high-efficiency building. Each BCA provided the following distribution counts
for POH magazines during their individual events (data present where available):
• BCA of Southwest Idaho Spring (Boise):110,000 --•. �
• BCA of Southwest Idaho Fall (Boise):106,000 �� m
• Snake River Valley BCA Fall:34,000 _
A�"""IKOWI�n EncrlY
FH -- OD•D0
• Eastern Idaho Home Builders Association:10,000 u
• Magic Valley Builders Association: 8,000 Figure 5 Residential Program Print Ad

2023 ANNUAL REPORT 17
The associates showcase and builder's expo,which go by different names ��.�������:a;
in each BCA but function in similar fashion, is a required event for builders
who enter homes in the Parade of Homes. Builders must attend to sign . _
POH contracts.These events provide the opportunity to interact face-to
face with builders, promote available rebates, and encourage builders to
integrate and promote the high-efficiency aspects of their parade homes.
As more builders join the BCA and showcase their homes in the parade of
homes,these events provide an opportunity to continue interacting with BCA
builders who are new to the Program alongside builders who were already
familiar with the Program. Figure 6 shows the booth the Company set up at
the Idaho Falls Builder Expo with help from the Idaho Falls Energy Service
Representatives. Figure 6 Eastern Idaho Building Contractor
Parade of Homes Kickoff
One of the most popular events for the BCA is the annual golf tournament
held by each BCA. Hosting a golf hole provides a good opportunity
to connect with builders in each BCA.As teams progress through the
tournament, Intermountain has an opportunity to interact with every
tournament player at the tee box.The Company provided a booth with
information about available rebates, snacks, refreshments,and branded
swag items to attract participants. Branded swag items for these events
included carpenter pencils, multi-tool pens, plastic cups,golf ball marking = ''
tools and notebooks.An energy efficiency-related game is also used to /
engage with players by offering a prize at the "efficiency hole" Golf teams
compete to complete the hole most efficiently, or in the shortest amount of Figure 7 Sample of Intermountain EE
Branded Give Away Items
time. These events provided outreach opportunities to BCA builders who do
not participate in the Parade of Homes as well as adjacent industries such
as HVAC contractors, lenders, and real estate agents.At one tournament,
after learning about the Energy Efficiency Program for the first time, a group
of realtors requested energy efficiency brochures to place in their office
for visitors to receive more information about the Program.A sample of the -
branded swag items can be seen in Figure 7, and an example of the booth
setup used at golf tournaments can be seen in Figure 8.
n
Intermountain also leveraged a first-time opportunity as the featured speaker
at the monthly lunch meeting of the Snake River Valley BCA's Professional
Figure 8 BCA of Southeast Idaho Golf
Women in Building Council (PWB).This group is primarily composed Tournament
of women members of the BCA in a variety of home building adjacent
industries including home builders, real estate agents, and design companies
among others. EE staff and the Canyon County ESR, partnered to present an
informational session about the Energy Efficiency Program and builder issues
related to gas service.A picture of this event can be seen in Figure 9.
The Company also partnered with the Company's Business Development
department to sponsor the SRVBCA Economic Summit, an event where over I
300 BCA members attended a presentation on future economic forecasts
and housing trends. The Company received recognition as a major sponsor
throughout the event,distributed Program materials at the event,and Figure 9 Snake River Valley BCA
received podium time to address the audience. Professional women in Building

18 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
In 2023,there were 66 builders who received a whole home rebate,an increase of 5 from the 61 builders who
received one in 2022. In order to maximize savings opportunities, Intermountain provides a stack on option which
allows builders to stack on water heating and smart thermostat rebates to the Whole Home rebate. In 2023,there were
56 builders participating in the Program who also stacked-on a rebate in addition to their Whole Home rebate, up 7
from 49 in 2022.
Contractors
Contractors are valuable partners in helping our shared customers understand the available energy efficiency
incentives.As such, developing and maintaining relationships with contractors in the service territory continued to
be a priority in the outreach efforts.According to responses to "how did you hear about the Program,"on rebate
applications,the equipment dealer/installer continued to be the most common source of Company information for
residential rebate recipients.The Company continued to conduct outreach with contractors at in person events, by
utilizing direct messaging to contractors, and by working with the ESR team to gather contractor feedback received
from the field.
Intermountain Energy Efficiency staff were also invited to join a contractor training event coordinated by Rocky
Mountain Power. The event was held at an equipment dealer in Idaho Falls. Local contractors were invited to an
informational presentation about equipment. Intermountain, Idaho Falls Power and Rocky Mountain Power shared the
expense of providing lunch and each presented an overview of their respective energy efficiency programs.
Water heating, particularly the storage water heater rebate, has been a low performing rebate since inception of the
Program. Of the applications that were received for the storage water heater,the most common reason the application
is rejected is because the equipment did not meet the minimum efficiency required for the rebate. To help contractors,
and ultimately customers, better understand the rebate requirements,the Company sent a postcard focused solely
on water heating rebates and the minimum efficiency
requirements. The postcard was sent to 651 contractors ^RMOUNTAK
GAS CO PANY
in September and highlighted available water heating
incentives. In 2023, a total of 858 water heater rebates
were paid, an increase from the 617 water heater
rebates paid in 2022.An example of this post card is
shown in Figure 10.
^INTERMOUNTAIN° Energy
In 2023,there were 196 contractors identified on GASCOMPANY Efficiency
a rebate, an increase of 32 from 164 participating
contractors in 2022. Of these 196 participating Figure 10 Water Heating Contractor Postcard
contractors in 2023,103 were new contractors for this
year,while 93 were returning contractors.
Community
While raising awareness with customers remains the highest priority,the Company also leverages community-wide
opportunities to build Program awareness and energy efficiency in general.
Intermountain placed ads in local publications where community members may be looking for local community news or
business services.An ad was placed with the Pocatello/Chubbuck Chamber magazine,which distributed 5,000 copies
around various local service areas for Pocatello and Chubbuck(including hospital and healthcare facilities,the local
airport, hotels,and real estate offices), Chamber conventions and conferences,and to Chamber office sites.Another
ad was placed with the Sun Valley/Wood River Valley Real Estate Guide,where 20,000 copies are available through
a network of community pick-up sites in the Wood River Valley Area.The guide was also sent to over 1,400 local
homeowners and an online copy was available through the Idaho Mountain Express website.

2023 ANNUAL REPORT 19
In person events allowed the Company to interact face to face with members J
of the community and provide Program information.At the Portneuf Valley msrsenve
Environmental Fair in Pocatello, community members gathered for an Earth
Day celebration with food, music,and various local vendors supporting
more sustainable practices in their community. Intermountain hosted an
information booth with handouts, snacks,and information about the Energy n Energy
�cM oRMOUNTAIN" �MPANY Efficiency
Efficiency Program which can be seen in Figure 11. In Twin Falls,the Company
sponsored the South Central Community Action Plan's(SCCAP)100th Home
Celebration. During this celebratory event, members of the community as well
Figure 11 Portneuf Environmental Fair
as partners to SCCAP came together to celebrate their milestone of building Information Table
100 homes through the Self-Help Housing Program.The SCCAP Program
gives pre-qualified participants the opportunity to build alongside experienced,
professional home builders to help lower the cost of home construction and
achieve the goal of affordable home ownership. In recognition of the role of
energy efficiency in keeping home operations affordable, homes built through
SCCAP's Self-Help Housing Program include high-efficiency natural gas water
heaters and furnaces. During this event,visitors were able to tour homes in the
neighborhood where the 100th home was built to see what SCCAP's Program
had accomplished.As a sponsor, Intermountain EE hosted an information table
at one of the homes on the tour. Figures 12 and 13 show the event banner and
information table that the Company received as an event sponsor. Figure 12 Information Table at SSCAP
100th Home Celebration
Since customers are often exposed to many different forms of advertising
during their days,the Company continued exploring new ways of giving
customers consistent reminders of available resources.The Company worked
with the (IBR)
). carry out an online g g �. R,a, ...
RCAC
d ertising campaign In th s1e target ncampaign,viis to s to theIntermountain USDA Self-He p Housing
100 Home Celebration
EE residential web page from July 1st through October 15th received an _s,P-1,r 1110111,A,...,--
Intermountain EE themed ad on the next website they visited within thetsf�°°
Google ad network utilized by IBR.This was a "drip-drip-drip" campaign as the
Company ads followed digital readers through their electronic journey.This -- _ —
campaign was designed to generate 25,000 impressions via the Intermountain - -
EE themed ads over the course of the campaign.An `impression' is a single Figure 13 SSCAP 10tth Home Celebration
occurrence of an ad being displayed on a user's screen,and a single user Event Banner
could generate multiple impressions over a period of time by seeing the ad
on different websites. Over the course of this campaign there were 26,971
impressions generated and 37 clicks on these ads,which resulted in a 0.14% SAVE MONEY.
click through rate.Samples of the ads used in this online campaign can be seen SAVE ENERGY.
Unlock your savings
in Figure 14. with energy efficiency
rebates from
Since this was the first time the Company used online advertising performance, Intermountain Gas.
benchmarks for this advertising campaign were difficult to establish.As per IBR, 1_<_,>'_1 Energy
IMOUads placed directly on the IBR website average a 0.11%CTR,though this is a AGNAS T OMPANY AINm Efficiency
slightly different setting than the ads placed in the Google ad network. For this ;,t .-
reason,the Company has taken extra measures to collect data internally on the
performance of its various promotional campaigns.This will provide Company- SAVE"°NE"SAveE"ee�v.
specific benchmarks to compare to future campaigns where appropriate. 'DA®/� nergy
AWS<OMGnNV A Efficiency
The Company continues to look for ways to promote awareness at the Figure 14 IBR Online Ads
community level and support organizations that share the goal of providing
ways to lower energy consumption and cost through energy efficiency.

20 RESIDENTIAL ENERGY EFFICIENCY PROGRAM
PROCESS EVALUATION
In addition to the impact evaluation,a process evaluation was conducted with both participants(customers
who received a rebate) and non-participants(customers who did not receive a rebate). Evaluators attempted
to determine how customers learn about the Program and the best channels to reach them, points of entry,
barriers to participation, levels of satisfaction and suggestions for improvement.The full report is available in
Supplement 3: Process Evaluation Report.
Overall, Evaluators had four recommendations for the Company.The abbreviated recommendations are
presented here as well as the Company's proposed follow up actions regarding the recommendations.
Complete study findings and recommendations by the Evaluators can be found in Section 5.1 of the report,
page 31.
RECOMMENDATION 1
Program staff should consider boosting the program's marketing and outreach campaigns. Based on
respondents' communication preferences, program staff should also focus on more targeted email and mailer/
bill insert marketing campaigns,as well as website banners and announcements.
Action:The Company will continue to leverage email, mailers, and the website to provide energy efficiency
information to customers. Due to Company email opt-in policies, email communications can only be sent to
customers who opt-in to receiving energy efficiency themed email.The EE Program will continue to work
within Company policies and encourage customers to subscribe to email communications.The Company will
explore cost-effective marketing and outreach campaigns to continue to raise overall program awareness.
RECOMMENDATION 2
Intermountain should focus on the motivators of saving money on energy bills and improving the comfort
of homes when promoting the program to customers,focusing on the energy-saving potential of
equipment upgrades.
Action: It is helpful to know that in the numerous motivations for taking an energy efficiency action,saving
money and comfort are top of mind with Intermountain's customers.The Company website does have a page
dedicated to energy saving tips.An energy saving calculator is provided on the website to help customers
estimate how much they could save by comparing standard equipment to high-efficiency equipment.The
Company will continue to raise awareness about these tools to assist and motivate customers to engage in the
program and use energy efficient equipment.
RECOMMENDATION 3
Intermountain should consider increasing its direct-to-contractor outreach, promoting the program to
contractors,and educating them about the programs'offerings.
Action:The Company will continue to explore outreach direct to contractors and raise awareness about the
Program with contractors. Other programs and utilities have leveraged contractor membership organizations
like trade ally organizations to build more robust communications and partnerships with contractors.The
Company intends to explore this option,taking into consideration the resources required to administer
such a program.

2023 ANNUAL REPORT 21
RECOMMENDATION 4
Intermountain should consider updating the rebate application,so that it is shorter and clearer,and can
be submitted through an online portal. Intermountain should consider alternative payment plans and bill
structures that encourage efficient equipment purchases while minimizing the large upfront investment.
Action:The Company has given the rebate application great consideration with each iteration of the
application.The balance between simplicity and getting the required information is a challenge.The current
paper application is one page,front and back.With the proposed 2025 program change,the Company will
give extra attention to communicating clearly and simply regarding the required inputs for rebates.An online
application has been available since 2019. In 2024,the Company moved to an online portal, but because it
is only accessible once customers sign in to their customer account this would not have been visible to the
Evaluators.While other utilities and energy efficiency programs have found success in offering alternative
payment plans such as on-bill financing,the Company will not be pursuing this option due to the resources
that would be required for such a program.
ADDITIONAL RESEARCH QUESTIONS
While developing the final evaluation research plan, evaluators explored the additional research questions
regarding staffing, quality assurance and barriers to participation for this study.They found the staffing/
organization relative to the budget to be appropriate and quality assurance procedures to be appropriate
and effective. Evaluators also found Intermountain should consider additional marketing techniques and
strategies to reach non-participating customers. Non-participant survey results suggest more information
about the Program and the benefits of energy efficient equipment is needed. Finally,some participants
expressed difficulty communicating with Intermountain. Evaluators also believe the Company and participating
contractors would benefit from additional trade ally efforts.A brief table of these results are available on page
2 of the report while full details can be found in the body of the report.
Action:As mentioned in recommendations 1, 2, and 3,the Company will explore additional marketing
techniques and strategies and focus messaging on Program benefits such as saving money and energy.The
Company strives to provide a superior customer experience by responding to inquiries in a timely manner,
meeting the stated response times of 1-2 business days for all phone calls and emails.The implementation of
ERA and the customer web app will provide the Customer Experience Team at the call center with visibility to
the status of customer's rebates and will allow for a more immediate response to questions about their specific
rebate as well as general energy efficiency questions. Finally,the Company will explore the benefits and
plausibility of implementing and administering a contractor trade ally program.

22 COMMERCIAL ENERGY EFFICIENCY PROGRAM
COMMERCIAL ENERGY
EFFICIENCY PROGRAM
The Commercial Program was approved by the Commission and went into effect as of April 1,2021.All customers
receiving natural gas through the Company's GS-1 rate class are eligible to participate in the Program.The Commercial
Program offers rebates on natural gas equipment meeting specific high-efficiency requirements and can be applied to
replacement equipment, conversion from other fuel sources,and new construction.
The Commercial Program is funded by the Energy Efficiency Charge(EEC-GS) rider, a monthly per therm charge
to commercial customers.As of June 30,2024,the Company had an over-collected EEC-GS Program balance of
$1,029,904. Because of the low uptake of the Commercial Program,the Company filed to decrease the EEC-GS rate.
On October 1,2024,the EEC-GS was reduced from $0.00320 to$0.00 per therm. In 2023,the Company paid out
$26,505 directly to customers in the form of incentive rebates.Table 15 provides full details of the December 31, 2023
commercial rider balance.
In this section, 2023 performance, cost-effectiveness, and lessons learned will be covered for each rebate. Commercial
Program outreach, promotion, and education activities are also included.
COMMERCIAL ENERGY EFFICIENCY PROGRAM
The UCT for the Commercial Program was 0.9,with a TRC ratio of 1.
Rebates
Condensing Unit Heater Incentive Table 15. 2023 Commercial Rider Balance
The Condensing Unit Heater incentive offers customers a $1,500 Revenue $ 474,181
rebate for the installation of a high-efficient unit heater with a minimum Program Expenses
efficiency rating of 90%AFUE.The Company received no applications Commercial Rebates 26,505
for the installation of this piece of equipment in 2023. Labor 33,641
Program Delivery 2,276
Boiler Reset Control Incentive Special Studies 11,513
The Boiler Reset Control incentive offers customers a $350 rebate Market Transformation 1,250
for the installation of a boiler reset control.The Company received no Direct Expenses (2,866)
applications for the installation of this piece of equipment in 2023. Total Program Expenses 72,318
High Efficiency Condensing Boiler Incentive 2023 Rider Deferral
The High Efficiency Condensing Boiler incentive offers customers Over/(Under)Collection 401,563
a $4.50/kBTUh incentive for the installation of a high-efficient Prior Year Rider Balance
condensing boiler with a minimum efficiency rating of 90%Thermal Over/(Under)Collection 463,938
Efficiency(TE)and a minimum input of 300,000 BTU.The Company
issued 2 rebates in 2023. Rider Account Balance
The incentive was cost-effective under the UCT analysis,with a cost- Over/(under)Collection $ 865,801
effectiveness ratio of 1.5.The TRC ratio was 0.9.

2023 ANNUAL REPORT 23
Fryer—ENERGY STAR Certified Incentive
The Fryer incentive offers customers an $800 incentive for the installation of an ENERGY STAR Certified Fryer.The
Company issued 20 rebates during 2023, an increase of one rebate over 2022.
The UCT for the fryer was 0.8 and the TRC was 1.1.
Steamer—ENERGY STAR Certified Incentive
The Steamer incentive offers customers a $1,100 incentive for the installation of an ENERGY STAR Certified Steamer.
The Company received no applications for the installation of this piece of equipment in 2023.
Griddle—ENERGY STAR Certified Incentive
The Griddle incentive offers customers a $200 incentive for the installation of an ENERGY STAR Certified Griddle.The
Company received no applications for the installation of this piece of equipment in 2023.
COMMERCIAL PROGRAM OUTREACH, AWARENESS
AND EDUCATON
In 2023,the Company continued to leverage previously utilized Commercial EE Web Page Visitors
methods of outreach to commercial customers as well as new lanes By Month for 2023
of customer communication.The Company continued to prioritize ° 300 —
building Program awareness among the commercial customer base v zso
a
and establishing relationships with valuable industry partners such as zoo
150
architects, engineers, and HVAC/plumbing contractors. 100
0
v so -
,,,,,..
Similar to the Residential Program,the Company instituted regular, 0 o
quarterly communications to commercial customers. In 2023, both z Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
email and bill inserts were used for these communications. Commercial Month
customers that have opted to receive email updates from the Program, Table 16 Commercial Web Page Visits 2023
about 9,000 subscribers, received an energy efficiency themed email 3
times in 2023. For the second quarter communication a bill insert was sent to all commercial customers.The Company
noticed a spike in web traffic during the months of February and September as a result of the emails sent at this time,
as seen in Table 16.
To reach professionals in commercial construction and
design with energy efficiency messaging,ads were
placed in several IBR publications.A full-page ad was � SAVE MONEY.
Build a better lomo>rozo. SAVE ENERGY.
placed in the IBR Book of Lists, an annual guide to the Choose natural gas waxy. Soak up the savings with
top businesses in Idaho, providing valuable insight energy efficiency rebates.
h your home or h your business.higneMicie
into the companies that make up Idaho's dynamic �,i,m nt an 1p yo maximize yourerergy
11 ark your comfort.Eam rebates when you
mtall qualiYying equipment.
omplete Ilse of avaibble (a °
marketplace.The Book of Lists is a directory of contacts eb, .program req"irem ma
and ere.gy saving tips,ki
for businesses in a variety of industries.The Commercial
Program advertisement was strategically placed in the ' �� Energy
6wMRMOUNTAIN'
construction section with the top rankings of builders and j�Z CAS COMPNNY Efficiency
HVAC contractors. The Company also placed a full-page
ad in the IBR Top Projects Edition of their magazine, a �—
publication featuring detailed information about the top
OEmm
construction projects completed in Idaho. Examples of
these ads are provided in Figures 15 and 16. Figure 15 Commercial Print Ad Figure 16 Commercial Ad OR

24 COMMERCIAL ENERGY EFFICIENCY PROGRAM
In addition to the annual publications, Intermountain leveraged an advertising
campaign offered by IBR which included an add on the IBR website,a print BUILD THE FUTURE
ad in the magazine and an ad in a weekly business e-newsletter.An example EFFICIENTLY.
of the ad is provided in Figure 17.The Commercial digital ad was visible on Commercial Energy Efficiency Rebates.
the Idaho Business Review website along with a quarter page ad in the print
magazine. IBR reported the online ad received 22,064 impressions and 21
clicks,for a 0.10%click through rate.The print ad went to an estimated 4,824 AI ETN RMOUNTAIN' Energy
WW�i
print readers.An ad was also placed in the IBR Development Newsletter GAS COMPANY Efficiency
which focused on the topics of construction, development,and real estate.
The Intermountain Commercial EE ad ran for five consecutive weeks in the
e-newsletter sent to IBR subscribers.This ad which linked the reader to the Figure 17 Commercial Ad in IBR
commercial web page generated 3,780 impressions,9 clicks, and a 0.24%
click rate, above the industry average 0.15%.
To keep energy efficiency top of mind in the preliminary stages of building
planning and design, Intermountain aimed to foster relationships with — ti_-
industry organizations such as the Idaho chapters of the American Society
of Heating, Refrigeration,and Air Conditioning Engineers(ASHRAE)and
the American Institute of Architects(AIA). In a similar fashion to Building
Contractor Associations,these associations host annual golf tournaments for
the association membership which includes HVAC and plumbing contractors,
Figure 18 Boise Chamber of Commerce
engineering firms and equipment dealers among other commercial Golf Tournament
construction adjacent industry members. The Company sponsored a booth
at the ASHRAE tournament to raise awareness about the Commercial
Program with ASHRAE members.To continue to focus on reaching
businesses, EE participated in events with local chambers of commerce.
The Company hosted information booths at both the Boise Metro Chamber
of Commerce annual golf tournament and,for the first time ever the Eagle T
Chamber of Commerce.This provided an opportunity to reach out to fellow
chamber members who are also Intermountain commercial customers as
�� ouKraN is a�,
well as development companies, real estate agents and business owners.An
example of the booth set up at these events can be seen in Figure 18.
Figure 19 AIA Design Awards Information
Like the Residential Program,contractors and installers play a key role Table
in promoting energy efficient options.And, like the Residential Program,
while savings opportunities exist in the equipment replacement market,
considerations regarding energy efficiency are also important in the design ,
phase. For this reason,the Company also implemented several outreach
efforts to engineers and architects in the commercial sector. ° s
In order to maximize outreach efforts, Intermountain was a sponsor of the Build a better[omorro&
biennial signature event,the AIA Idaho Design Awards conference.This "r
is a 2-day event where AIA members from around the state converge
for informational seminars and award presentations. The event provided 1
an opportunity to raise awareness with architects and building design
professionals. On both event days, Intermountain provided an information
table to share Commercial Program brochures and promotional items as
seen in Figure 19.Additionally, Intermountain was recognized as a sponsor ; o^. °�lo®
throughout the event and was also provided ad space in the event agenda
Figure 20 AIA Design Awards Program
and brochure shown in Figure 20. Book 2023

2023 ANNUAL REPORT 25
Finding ways to educate and inform building operators for Intermountain commercial customers and developers
during the design phase of a new commercial building continues to be a top priority for increasing participation in the
Commercial Program.The Company will continue to explore ways of reaching key decision makers such as building
operators so they can integrate the Program's resources at the appropriate time in their equipment replacement or
construction process. Continuing to engage contractors who work with commercial customers also remains a crucial
factor in helping commercial customers obtain the Program's resources.
Lessons—Commercial Program
The Company is still learning about its customers,their interest in energy efficiency and more importantly getting
energy efficiency messaging to the right audience. Unlike the Residential Program where it is relatively easy to reach
the decision maker,the homeowner, it is not as easy in the commercial sector.Although Intermountain has a customer
contact on file,the commercial customer contact on record isn't necessarily the person who manages equipment
for the company or is familiar with building equipment.This sentiment was echoed in EESC feedback indicating
commercial customers aren't always familiar with the equipment they have on site or what equipment might be eligible
for an energy efficiency upgrade.
To learn more about commercial customers Intermountain contracted with the Integrated Design Lab to help develop
a comprehensive commercial customer survey. The survey will be sent to commercial customers through several
methods: snail mail postcard,email, and bill insert. One of the goals of the survey is to identify the building operator
or facilities manager for the account,which will allow Intermountain to build a database of building operators and
communicate directly with personnel who are familiar with building equipment, rather than administrative or accounting
people responsible for paying the gas bill.There is also a question to inquire if the building operator holds a building
operator certification (BOC),as BOC was identified as a high savings opportunity in the last Conservation Potential
Assessment. This will allow the Company to explore the potential of offering certification as part of the commercial
offering.The remainder of the survey asks about specific gas equipment in the building as well as interest in learning
about energy saving opportunities and upcoming projects or equipment upgrades.To encourage participation in
the survey,the Company will offer a $10 gift card for completed surveys. Survey participants will receive a link to
Tango rewards and will be able to select a $10 e-gift card from the vendor of their choice.The survey is applicable
to commercial customers and will be available for the foreseeable future as the Company continues to learn about
commercial customers.
To implement additional savings opportunities identified in the 2023 CPA into the Commercial offering,the Company
plans to have a Commercial TRM developed in order to apply a deemed savings approach like the Residential
Program.The Company will also explore adding a full time Energy Efficiency Outreach Analyst for the
Commercial Program.

26
ENERGY EFFICIENCY
STAKEHOLDER COMMITTEE
Intermountain conducted two meetings with the EESC. The EESC met on May 5 and November 2, 2023. The May
meeting provided an update on the rider balance for the residential and commercial programs, as well as a detailed
review of 2022 promotional activities and rebate performance.
At the November meeting,the Company proposed a meeting "makeover."The Company proposed implementing a
standard agenda for the EESC committee meeting.Standard agenda items would provide updates on the following: a
safety moment, rider balance, rebate performance, promotion and outreach update, Program administration, special
studies,and special topics.The remainder of the meeting followed this precise agenda. Building Code Specialist Ty
Jennings was the speaker for the special topics agenda item and provided an update on the proposed rule chapter for
Idaho Commercial and Residential building code. EESC meeting transcripts are provided in Supplement 4.
SECURING AN ENERGY
EFFICIENT FUTURE
Intermountain is continually exploring cost-effective energy saving solutions that can be implemented today, in addition
to seeking the energy saving measures of tomorrow.The Company participated in several member driven groups,
each focused on different stages and efforts of bringing new innovative energy saving products to market:
• The Emerging Technology Program (ETP) is a membership-based utility collaboration governed by GTI Energy.
The collaboration works to"accelerate the commercialization and adoption of energy efficient technologies," and
"provides expertise for program planning, implementation and assessment as well as tailoring initiatives to meet
regional needs, support pilots and custom programs."S
• The Company continued its membership in the North American Natural Gas Heat Pump Collaborative
(Collaborative)since joining as a charter member in 2019.The Collaborative is comprised of sixteen dual fuel
utilities and energy efficiency program administrators and represents 37%of all U.S. and Canadian households
using gas.6
• MDU Resources Group is a corporate member of the Energy Solutions Center(ESC). ESC is a non-profit
organization that promotes energy-efficiency natural gas solutions for use by residential, commercial,and industrial
energy users. ESC also creates educational and marketing materials,case studies and training manuals to "enhance
the success of those utility customer service professionals responsible for enhancing customer productivity,
efficiency, reliability and comfort."'Through corporate membership,the Energy Efficiency team is an active member
of the Gas Heat Pump Consortium, a member driven group whose objective is to "prepare communication and
marketing outreach materials as well as studies and tools to alert and educate end users, engineers architects,
consultants, installers,contractors and trade allies about higher efficiency, lower carbon HVAC options"
The Intermountain Energy Efficiency team participated in the Spring and Fall ETP meetings.These sessions are
dedicated to updates on the market readiness of emerging technologies, as well as the status and outcomes of
equipment pilot assessments and demonstrations for residential and commercial HVAC,water heating and commercial
food service.
5 Emerging Technology Program•GTI Energy
6 North American Gas Heat Pump Collaborative I Technology for a Cleaner Future
7 Energy Solutions Center I Accelerating Gas Fuel Technologies

2023 ANNUAL REPORT 27
The Collaborative continued to work to extend its reach and support from 0 Nortb American
��Gas Hea[Gump ColfaboratiVe
industry participants.With the structure of the organization well established,
and support documents such as installation considerations,opportunity briefs Next generation
and value propositions in place,the Collaborative turned to external outreach. space and
water heating.
In addition to strategically growing their presence on social media, specifically ___
Linkedln,the Collaborative also identified industry conferences and events
where they could host an information table to both share information about gas
heat pumps as well as recruit new Collaborative members.The Collaborative
leveraged outreach at the Midwest Energy Solutions conference by utilizing the Figure 21 NAGHPC Informational
booth space of a Collaborative member to provide gas heat pump informational Postcard
materials to conference attendees.A sample of the Collaborative information
card is provided in Figure 21.
The Collaborative also partnered with the Energy Solutions Center's Technology and Market Assessment Forum.
Forum attendees and Collaborative members participated in a 4-hour meeting with gas heat pump manufacturers
to get an update on the status of the gas heat pump production pipeline.The Collaborative also advocated to reject
ENERGY STAR's proposed phasing out of residential natural gas furnaces as well as rejecting the sunsetting of
ENERGY STAR natural gas boilers.The Collaborative will work to support the creation of an ENERGY STAR certification
pathway for gas heat pumps.
The Collaborative was also instrumental in securing an article in the Association of Energy Services Professionals 2023
Energy Intel quarterly magazine,titled, "Gas Heat Pumps Key to Decarbonization Puzzle"There were two working
committees,the Res HVAC Committee and the Gas Heat Pump Water Heater Committee.After studying the water
heating market and the slow development of the gas heat pump water heater,the Collaborative decided to sunset the
Water Heater Committee and instead approved the creation of the Commercial Gas Heat Pumps Committee.
Participation in the Collaborative provided a valuable network of industry partners working together to bring gas
heat pumps to market,work the Company could not achieve as a solo effort.As the committees embark on specific
projects, like an adoption forecast modeling tool,and additional resources are required to do the work, investment
beyond the membership fee,$25,000 for the 2023 membership,will be required.While valuable and important work,
it is unlikely the Intermountain Program can cost-effectively support any additional investments in the Collaborative.
The Company will carefully consider further involvement in the Collaborative in 2024.
The EE team is an active member of the ESC Gas Heat Pump Consortium (Consortium). Participation in the Consortium
is free and available to EE staff through the MDU Resources corporate membership. Participation in the Consortium
provides the Company access to member-only resources, like updates from gas heat pump manufacturers, case
studies and reports,and member utility success stories. In 2023,the Consortium produced materials for members to
use to raise awareness and provide education about gas heat pumps;such as the Gas Heat Pump Solutions magazine,
currently featured on the Intermountain EE website, and gas heat pump marketing materials and infographics that
can be co-branded and customized to Intermountain's customers. In 2023,the Consortium created a free,70 minute,
"Introduction to Gas Heat Pumps" on demand webinar for commercial businesses, contractors,engineers, installers,
consultants, plumbers, or anyone involved in HVAC installations.The webinar can be accessed anytime and will help
Intermountain raise awareness and education around gas heat pumps.The Company promoted the webinar with
contractors. Following the webinar, ESC provided a post-webinar survey which allowed participants to indicate if they
were interested in learning more about gas heat pumps.The Company followed up with these participants and sent
gas heat pump resources including links to the web page for the North American Gas Heat Pump Collaborative, a
digital copy of the 2023 Gas Heat Pump Solutions Magazine from ESC,and links to the Intermountain Commercial
Energy Efficiency website and the Company's pages dedicated to gas heat pump information.

28
ENERGY EFFICIENCY: NEXT STEPS
The Company strives for continual improvement and opportunities to increase cost-effective savings for Intermountain
customers in the ever-evolving environment of energy efficiency. Industry partners, collaborative efforts and an
engaged and robust EESC continue to be joint partners in this shared mission.
In Order No. 36245, issued in case No. INT-G-23-06,the Idaho Public Utilities Commission deemed the 2022 Program
expenses as prudently incurred. In accordance with the Order, in 2023 the Company conducted a billing analysis of
the Whole Home Tier I and Tier II and the furnace and smart thermostat measures.And in so doing, addressed the
smart thermostat EUL as ordered. Likewise,the Company will continue to strive for proficiency in delivering the energy
efficiency program and securing cost-effective savings by seeking ways to reduce labor expenses.The final item of
Order No.36425 instructed the Company to develop and follow a schedule for regular internal audits. The 2025 audit
plan in currently in development and will be approved by the MDUR Board of Directors in February 2025.
In addition to the impact evaluation completed in compliance with Order No.36245, an impact evaluation was also
conducted on water heating measures to inform future program changes. The Company also commissioned a process
evaluation which will help inform outreach and awareness strategies for energy efficiency. By applying the IGC TRM
and the 2023 IRP Avoided costs,these studies will be implemented into the proposed program in 2025 to continue to
secure cost-effective savings.
The Company will continue to raise awareness about the Commercial Program and will use the commercial customer
survey to learn more about the needs of these customers. In addition, identifying the correct contacts at commercial
customers will allow the Company to target outreach where it will provide the biggest return. The Company plans to
commission the development of a commercial TRM in order to offer a more robust listing of energy saving prescriptive
measures for commercial customers.
The Company continues to strive to secure cost-effective savings for Intermountain residential and commercial
customers,through traditional methods of resource acquisition; rebate programs; as well as working towards an
energy efficient future through market acceleration of energy efficient technologies and equipment.

INTERMOUNTAIN°
GAS COMPANY
A Subsidiary of MDU Resources Group,Inc.
In the Community to Serve®
Intermountain Gas Company
555 S Cole Road
Boise, ID 83709
Tel: [phone]
Fax: [phone]
0 © O 0