20240315Reply Comments.pdf

COMPANY REPLY COMMENTS PAGE 1 OF 12
Preston N. Carter, ISB No. 8462
Morgan D. Goodin, ISB No. 11184
GIVENS PURSLEY LLP
601 West Bannock Street
P.O. Box 2720
Boise, Idaho 83701-2720
Office: [phone]
Fax: [phone]
[e-mail]
[e-mail]
18248498.5

Attorneys for Intermountain Gas Company

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF INTERMOUNTAIN
GAS COMPANY’S APPLICATION FOR A
DETERMINATION OF 2022 ENERGY
EFFICIENCY EXPENSES AS
PRUDENTLY INCURRED

Case No. INT-G-23-06

INTERMOUNTAIN GAS COMPANY’S
REPLY COMMENTS

Intermountain Gas Company (Intermountain or Company) respectfully submits the
following Reply Comments in response to comments filed by the Idaho Public Utilities
Commission Staff (Staff) and the City of Boise (City).
COMPANY REPLY COMMENTS
1. The Company has used, and will use, data collected through a billing analysis when
that data becomes available for particular offerings. Billing data is not currently
available for the rebates approved in Order No. 34980.
The Company’s energy efficiency program is, by necessity, an iterative and cyclical
process. Energy efficiency offerings must be proposed; implemented for a number of years,
preferably at least two full cycles; studied and evaluated, typically through an EM&V study; and
revised based upon the evaluation.
Each step of the process must be carried out with the data available at the time. Proposal
and implementation must be accomplished using projected or simulated data; this is the best, and
RECEIVED
Friday, March 15, 2024 2:25PM
IDAHO PUBLIC
UTILITIES COMMISSION

COMPANY REPLY COMMENTS PAGE 2 OF 12
indeed only, data related to particular offerings at this stage in the cycle. Real-world data
regarding the offerings are collected during the implementation phase. This data, including
billing data, is used to conduct a billing analysis during the evaluation phase. The billing analysis
can then be used to revise the offerings, as needed.
This cycle takes several years to complete for each offering. To obtain valid and reliable
data, each particular offering must be implemented for at least two full annual cycles. Otherwise,
the analysis of each offering would be unduly influenced by, among other things, the particular
rate of uptake during a given year and the weather during the year. In short, implementing a
particular offering for at least two full annual cycles is necessary to ensure that the data used
during the evaluation phase—including a billing analysis—is accurate.
In this proceeding, Staff takes issue with three offerings: Furnace; Whole Home Tier I;
and Whole Home Tier II. Staff Comments at 5. Staff contends that the Company failed to
evaluate the cost-effectiveness of these offerings using billing data, in violation of prior orders
from the Commission.
It’s true that the Company has not evaluated the cost-effectiveness of these offerings
using a billing analysis. That is because billing analysis is not yet available for these offerings.
As explained in more detail below, these offerings are still in the implementation phase. They
will be evaluated, including through a billing analysis, by the EM&V study that will flow from
the Request for Proposals (RFP) issued during this proceeding.
The Furnace, Whole Home Tier I, and Whole Home Tier II offerings were approved in
their current form by the Commission in Order No. 34980, issued in March 2021.1 See Case No.

1 The positions of the Company and Staff in this case appear to flow from a different understanding of the offerings.
Staff’s position appears to be based on an understanding that these offerings existed in their current form before
2021. While a version of these offerings did exist before 2021, they were significantly altered in Order No. 34980.

COMPANY REPLY COMMENTS PAGE 3 OF 12
INT-G-20-06, Order No. 34980 at 4-5 (March 30, 2021). The Company began implementing
these offerings on April 1, 2021. The tariffs approved in Case No. INT-G-20-06 are specific to
the revised offerings; for example, the tariffs reflect the amount of the rebate approved by the
Commission. In addition, the Company’s supplement in that case clearly identified the basis for
the annual therm savings for each rebate, leaving no doubt as to the therm savings and other
information approved by the Commission in that case. See Case No. INT-G-20-06, Supplement
to Application and Exhibits, Exh. 7 at 9 (filed Dec. 7, 2020).2
In July 2021, the Company filed Case No. INT-G-21-03. Because implementation of the
new offerings had just begun, this filing included the old program offerings, which were
evaluated using simulated and billing data. In Order No. 35313, filed in February 2022, the
Commission ordered that the Company evaluate its energy-efficiency offerings using the most
accurate evaluation method “when the Company has sufficient data to fully evaluate the
portfolio-wide and individual measures.” Case No. INT-G-21-03, Order No. 35313 at 4 (Feb. 8,
2022 (emphasis added).
In July 2022, the Company filed INT-G-22-03. This case evaluated the cost-effectiveness
of both the old offerings and the new offerings that began in April 2021. The old offerings were
evaluated using both simulated therm savings and a billing analysis. Because a billing analysis
was not available for the new offerings, the Company evaluated them using the estimated therm

From the Company’s perspective, the Whole Tier I and Whole Tier II offerings approved in Order No. 34980 are
significantly different from the prior offerings, such that their cost-effectiveness must be based on data specific to
those offerings. The Furnace offering approved in Order No. 34980 significantly revised the data points collected to
allow for more robust billing analysis in the next EM&V review. The Company believes this position makes sense –
why would you revise offerings and then evaluate the revised offerings based on data for the pre-revision offerings?
This would assume that, after revision, the offerings would be just as cost-effective as before the revisions. And the
whole point of revisions is to make offerings more cost-effective. The Company agrees that offerings should be
evaluated using the best data possible; this is data based on implementation of the particular approved offerings.
2 Exhibit 7 to the Supplement is attached for reference.

COMPANY REPLY COMMENTS PAGE 4 OF 12
savings used in developing the rebates. The Company filed a supplement in that case, which
contained a schedule for EM&V studies related to the various offerings.3 Case No. INT-G-22-03,
Supplement 1 – 2021 Cost-Effectiveness (filed July 12, 2022) at 4. According to the schedule, an
EM&V study evaluating the new offerings would be completed using data for the year ending
2023, meaning that the data from 2023 would be used in an EM&V study conducted in 2024,
such that the results of the EM&V study would be available for use in the prudency case filed in
2024. Id. at 23 (EM&V schedule indicating that an EM&V study for Furnace, Whole Home Tier
I, and Whole Home Tier II offerings would be conducted using data at the end of the year 2023).
The Commission issued Order No. 35663 in January 2022. Order No. 35663 ordered the
Company to, among other things, “submit an RFP for a third-party contract to conduct an impact
evaluation with billing analysis for the Whole Home and Furnace measures to be included in its
2023 prudency filing.” Order No. 35663 at 9. Submitting the RFP for Staff’s review during the
2023 case is consistent with the schedule provided by the Company in INT-G-22-03, which
contemplated conducting an EM&V study using data from the end of the year 2023, such that the
results from this study could be used in the prudency case filed in 2024. See Supplement 1 at 9.
The Company filed this case in October 2023 and simultaneously submitted the RFP to
Commission Staff. The Company issued the RFP shortly after conversations with Staff made it
clear that Staff had expected the RFP to be issued prior to this case, such that its results would be
used in this case.4 The EM&V study will analyze data from implementation of the new offerings,

3 This Supplement is attached to these comments, as well.
4 The Company believes the Commission’s direction was clear: submit the RFP to the Commission in this
proceeding, so it could be reviewed and issued with Staff input in time for the study’s results to be used in the 2024
case. In any case, any misunderstanding has now been cleared up.

COMPANY REPLY COMMENTS PAGE 5 OF 12
including billing analysis, to be used for evaluating and potentially revising the offerings in the
prudency case filed in 2024.
Looking back, it may seem like this cycle took a long time. But it is not outside the norm.
Implementation of these offerings began in April 2021; the offerings were implemented for two
full yearly cycles, 2021-2022 and 2022-2023; and they will be evaluated using actual data,
including a billing analysis, in 2024. While Staff may desire a quicker turn-around time,
offerings must be in place for an adequate period of time to ensure sufficient and accurate data to
use during the evaluation phase.
The Company recognizes the Commission’s direction to use the most accurate
information to evaluate the efficiency of its offerings. The Company also recognizes the
Commission’s view that a billing analysis may provide the most accurate source of information,
and that the Commission will likely use the billing analysis to evaluate the cost-effectiveness of
its offerings unless the Company persuasively argues otherwise. A billing analysis is not
available, however, for the offerings approved in Order No. 34980. Billing data for these
incentives will be obtained during the EM&V study that will flow from the RFP issued in this
case. When that billing data is available, the Company will use that data as part of evaluating the
cost-effectiveness of these revised incentives. And the Company recognizes that the billing data
will be an important part of the Commission’s decision regarding whether to adjust or alter these
offerings, on a going-forward basis, in the next prudency filing.
As noted, Staff contends that the Company’s failure to use billing data for these revised
incentives violates prior orders from the Commission. Staff Comments at 5. The Company
strongly disagrees. Billing data for these revised incentives is not available and therefore cannot
be used. The Commission’s orders acknowledge that the most accurate method should be used to

COMPANY REPLY COMMENTS PAGE 6 OF 12
evaluate the cost-effectiveness of offerings, and that a billing analysis is often the most accurate
data. It is not accurate to evaluate the cost-effectiveness of the new offerings based on a billing
analysis of the old offerings.
The Company’s approach in this case does not reflect a rejection of the Commission’s
guidance; it reflects only the reality that a billing analysis of the new offerings must be based on
the real-world information related to those offerings. The Company recognizes the importance of
billing data and will continue to collect and use it. But Intermountain can’t be expected to
analyze the cost-effectiveness of offerings using a billing analysis, when a billing analysis isn’t
reasonably available for the offerings at issue.
2. Billing data related to rebates that are no longer in use cannot be used to evaluate
the cost-effectiveness of the rebates that are currently in use. Regardless, rebates
within a Commission-approved tariff must be adjusted prospectively rather than
retroactively.
Staff recommends disallowance of approximately $706,000 in expenditures related to the
Furnace and Whole Home rebates. Staff Comments at 2. Staff does not dispute that the
Company’s expenditures were consistent with Commission-approved tariffs; there is no dispute
that the expenditures were, in fact, consistent with the tariffs. Staff recommends the disallowance
because it perceives the Company’s filing in this case to be out of compliance with other orders
due to the use of projected savings versus a billing analysis. Staff Comments at 5. To calculate
the disallowance, Staff uses the billing analysis provided in Case No. INT-G-21-03—which
related to the old offerings and applies them to the new offerings.5 See Staff Comments at 8 n.2.
Specifically, Staff calculates its disallowance by using the results of the EM&V Study in INT-G-
21-03, which used data through the end of the year 2020; assumes that an EM&V Study on the

5 As noted above, in INT-G-21-03 the Company proposed, and the Commission approved, use of the CPA therm
savings for the Furnace offering to collect additional billing data as recommended in the EM&V study.

COMPANY REPLY COMMENTS PAGE 7 OF 12
new offerings with data through the end of the year 2022 would result in the same ratio of
estimated savings when compared to savings measured using billing data, and then applies that
ratio to the estimated therm savings in the Commission-approved tariffs. Id.
This recommendation is problematic for several reasons.
First, information related to old offerings cannot be used to evaluate new offerings. The
Commission has indicated a strong preference for the use of the most accurate information to
evaluate the cost-effectiveness of energy-efficiency measures. See Order No. 35313 at 4
(directing the Company to use “the best available data” and to “use the most accurate evaluation
method”). Billing data based on offerings that were revised due to their lack of cost-effectiveness
is not accurate as applied to the revised offerings. The new offerings must be evaluated using
data that relates to those offerings. This is particularly true when the old offerings were revised
because those old offerings were not cost-effective. In addition, Staff’s attempt to use billing data
for year-end 2020 to guess at the outcome of a billing analysis using year-end 2022 data is
unsupported and does not reflect the best available data or information. It would be arbitrary to
apply billing data from offerings that are no longer in effect to the offerings that are in effect, and
to use data from year-end 2020 to presume the outcome of a billing analysis through year-end
2022.
Second, Staff recommend disallowance of expenditures that were made consistent with
tariffs approved by the Commission. The Commission specifically approved the design and
amount of the Furnace and Whole Home offerings. Order No. 34980 at 7. Two conclusions flow
from this: 1) at the time the expenditures were incurred, they were approved by the Commission
in a proceeding to determine their prudency; and 2) the Company was legally obligated to

COMPANY REPLY COMMENTS PAGE 8 OF 12
expend these amounts in compliance with the terms of the tariff. It would be arbitrary to disallow
expenses that were incurred in accordance with a Commission-approved tariff.
Staff argues for the disallowance based on its position that in this filing the Company did
not comply with the Commission’s orders. Staff Comments at 5. As set forth above, the
Company disagrees. But even if it were true, it would not be grounds for an after-the-fact
disallowance. Expenditures by the Company made in compliance with a Commission-approved
tariff are just, prudent, and reasonable. The Company’s actions in this filing cannot retroactively
convert those expenditures from just, prudent, and reasonable to unjust, imprudent, or
unreasonable. If Staff is concerned about the cost-effectiveness of the offering, that is a fair
position to make in the case. But that would provide, at most, a basis to prospectively adjust the
tariffs to make the offerings cost-effective.
Stated another way, Staff recommends a disallowance of past expenditures, which were
consistent with Commission-approved tariffs, based on a perception of the Company’s current
conduct. Disallowances are not equivalent to fines; they are not intended to be punitive.
Expenditures that were consistent with the tariffs in effect at the time should not be disallowed
on this basis. If any adjustment to the offerings are appropriate, the adjustments should be made
on a prospective basis by revising the tariffs.
3. The Company is administering an energy efficiency program as directed in its 2016
general rate case. If the program, or components of it, are not cost-effective, then
the Company is amenable to sunsetting them on a prospective basis if and as
authorized by the Commission.
The Commission authorized Intermountain Gas to create an energy efficiency program in
Order No. 33757. See Case No. INT-G-16-02, Order No. 33757 at 37-38 (April 28, 2017). The
Company has administered the program on an iterative basis since then. The Company has no
objection to sunsetting all or portions of the program if and as authorized by the Commission.

COMPANY REPLY COMMENTS PAGE 9 OF 12
The Company submits that administering the program will become difficult if there is a
risk of large disallowance of expenditures made in conformance with Commission-approved
tariffs. If all or portions of the program are to be retired, the Company requests that the
Commission do so on a prospective basis with clarity as to what, if any, specific offerings are to
be allowed on a going-forward basis.
4. The Company believes that its internal controls are adequate, but is open to
exploring the possibility of in-house audits with the understanding that labor costs
will necessarily rise.
Staff expresses concern regarding the Company’s internal process controls,
recommending that the Company should develop a schedule for regular internal audits. Staff
Comments at 4. Elsewhere, Staff recommends that “the Company reduce labor costs wherever
possible.” Id. at 3.
The Company does not agree that its internal controls are lacking. In prior cases, Staff
has indicated that its internal controls were adequate. See Order No. 35313 at 1 (“Staff . . .
verified that expenses were well documented and that internal controls appeared to be in place to
prevent improper payment of incentives and to properly record expenses.”); Order No. 35663 at
2 (“Staff verified that expenses were well documented and internal controls appeared to be in
place to prevent improper payment of incentives and to properly record EE Program expenses.”);
Order No. 34980 at 3 (“Staff’s audit of the Company’s EE Program ‘verified that expenses were
well documented and that internal controls appeared to be in place to prevent improper payment
of incentives and to properly record EE Program expenses.’” (quoting Staff comments)); Order
No. 34536 at 2 (“Staff verified the Company had sufficiently documented the expenses and had
internal controls to prevent improper incentive payment and to properly record EE Program
expenses.”). The Company’s internal controls have not changed.

COMPANY REPLY COMMENTS PAGE 10 OF 12
In any case, the Company’s energy efficiency program is audited as part of the EM&V
study process, which will occur in 2024. To clarify, there are two types of EM&V studies: an
impact analysis, which evaluates the cost-effectiveness of offerings, and a process analysis,
which reviews a company’s implementation of the program, including the company’s internal
controls. The Company has confirmed that the 2024 EM&V study will include both an impact
analysis and a process analysis. Accordingly, the Company’s internal controls will be reviewed
by a third party this year, with the results to be presented in the 2024 prudency filing. The
Company will address any internal-controls issues identified in the course of the EM&V study.
That said, the Company is open to exploring the possibility of developing the capacity for
internal audits. This will, however, require an increase in labor costs, which is inconsistent with
Staff’s recommendations in this and prior energy efficiency cases. The Company requests that
the Commission recognize the inevitable rise in labor expenses if it orders the Company to
develop capacity for internal audits.
5. Energy Efficiency Stakeholder Committee
The Energy Efficiency Stakeholder Committee (EESC) has been an important part of the
Company’s energy efficiency program since its inception. The current rebates resulted from a
collaborative effort between the Company and the EESC, and the Commission has recognized
the importance of the EESC in continuously improving the program. See Order No. 34536 at 5
(“We encourage the Company to collaborate with Commission Staff and appropriate advisory
groups to tailor its EE Program incentives to attract customers and developers and offer cost-
effective energy efficiency measures for the Company.”); Order No. 34980 at 8 (We direct [the]
Company to continue to work with the EESC to update its avoided cost method and, when
complete, present the results to the Commission as part of its next EE Program prudency case.”);
Order No. 35313 at 4 (“We commend the work the Company and its EE Stakeholder Committee

COMPANY REPLY COMMENTS PAGE 11 OF 12
(“EESC”) are putting into vetting programs that deliver cost-effective savings to customers and
implore the continuation of these efforts to ensure relevant and effective programs are being
offered. The Company and its EESC are clearly working to provide a valuable DSM program.”);
Order 35663 at 10 (“The Commission commends the Company for continuing to adjust its EE
Program to deliver cost effective energy savings to customers, and the collaborative efforts of the
Company, its EESC, and Staff to provide and maintain a DSM program that has value.”).
Commission Staff has been a consistent and valuable participant in the EESC. The
Company believes that the EESC provides a forum to increase all stakeholders’ understanding of
the program and avoid, or at least reduce, issues such as those addressed in these comments,
including the timing, scope, and use of EM&V studies related to the Company’s program. The
Company believes that it is unfortunate that these issues were not raised or discussed during
EESC meetings.
These and other issues indicate the possibility that EESC may not be serving its intended
purpose from Staff’s perspective. The Company requests that the Commission confirm the scope
of EESC meetings, specifically whether the EESC is the appropriate forum to discuss concerns
with the program and proposed changes to the offerings.
Dated: March 15, 2024.
GIVENS PURSLEY LLP
By
Preston N. Carter
Attorneys for Intermountain Gas Company

COMPANY REPLY COMMENTS PAGE 12 OF 12
CERTIFICATE OF SERVICE

I HEREBY CERTIFY THAT on March 15, 2024 I caused a true and correct copy of the
foregoing to be served upon the following parties as indicated below:

Monica Barrios-Sanchez
Commission Secretary
Idaho Public Utilities Commission
P.O. Box 83720
Boise, Idaho 83720-0074
[e-mail]

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Michael Duval
Deputy Attorney General
Idaho Public Utilities Commission
11311 W. Chinden Blvd., Bldg. No. 8, Suite
201-A
Boise, Idaho 83714
[e-mail]

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Ed Jewell
Daphne Huang
Deputy City Attorneys
Boise City Attorney’s Office
150 N. Capitol Blvd.
Boise, Idaho 83701-0500
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[e-mail]
[e-mail]

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Wil Gehl
Energy Program Manager
Boise City Dept. of Public Works
150 N. Capitol Blvd.
Boise Idaho 83701
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Preston N. Carter
INTERMOUNTAIN GAS COMPANY’S
REPLY COMMENTS
CASE NO.INT-G-23-06
Attachment 1
Exhibit 7 from Supplement

EXHIBIT NO. 7
CASE NO. INT-G-20-06
INTERMOUNTAIN GAS COMPANY

Proposed Residential Energy Efficiency Program Revisions
(9 pages)

Intermountain Gas Company 
Proposed Residential EE Program Revisions 
Based on the recommendations from the EM&V study (see Exhibit No. 5) performed by ADM Associates, 
Inc. (ADM), input from the Energy Efficiency Stakeholder Committee (EESC) (see Exhibit No. 4), and 
other resources such as the 2019 Idaho Residential Energy Code Field Study (see Exhibit No. 8), the ADM 
“Residential Whole Home Modeling Results” memorandum (see Exhibit No. 8), the Idaho Code 
Collaborative, and upcoming energy code changes, the Company plans to update its Residential Energy 
Efficiency Program (EE Program) by retiring, adding to and revising its current set of rebates. Following is 
an outline of the proposed program in detail.  
No changes:  
Furnace ‐The only rebate offering that remains unchanged is the furnace rebate of $350 for a
natural gas furnace with a 95% AFUE minimum efficiency rating. The EM&V impact evaluation of
the furnace rebate found savings of 134 therms per rebate based on the Equivalent Full Load
Hours for Heating (EFLH) approach recommended by ADM (see Exhibit No. 5, page 84). The
EM&V study recommended that additional information be required on the furnace rebate
application to determine the efficiency of the equipment being replaced as well as the reason
for replacement, such as replace‐on‐burnout, early retirement, or new construction. The EM&V
study also identified HVAC sizing as an area for contractor training as over‐sizing, a common
practice in Climate Zone 5, negatively affects program savings (see Exhibit No. 5, page 32).
Additionally, the EESC suggested collecting the size of the equipment being replaced (see Exhibit
No. 4, page 10). Collecting these additional data points should help provide a more complete
picture from which to evaluate savings attributed to the furnace rebate in the future. The billing
analysis conducted by ADM provided measurable savings, “However, the observable energy
savings through billing analysis are much lower than expected equipment savings. Billing
analyses include any changes in household behavior, equipment, or occupancy, and therefore
may include factors other than the impact of improved equipment efficiency” (see Exhibit No. 5,
page 32). Because of the large variation in therm savings between the Billing Analysis approach
and the EFLH approach, the Company has decided to collect the additional information noted
above to help provide a more refined EM&V analysis in the future. In the meantime,
Intermountain will use the 2019 Conservation Potential Assessment (CPA) annual therm saving
estimate of 87 therms as a conservative therm savings estimate for this rebate. The furnace
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 1 of 9
rebate has shown consistent growth year‐over‐year, and the amount of furnace rebates year‐to‐
date for 2020 has already exceeded the 2,066 rebates issued in 2019. The cost‐effectiveness 
tests were based on an estimate of 2,500 rebates for 2021.   

Retirements:  
 70% Fireplace ‐The 70% FE Fireplace rebate had very low participation over the life of the 
offering with 13 and 14 units installed in 2018 and 2019, respectively.  While some customers 
may use a fireplace insert as a substitute heat source, fireplace inserts are designed to be a 
decorative feature and are therefore not normally rated for energy efficiency, or if rated, there 
is not a standard efficiency rating applied to all fireplace inserts. Based on the findings of the 
CPA, updated annual therm savings were reduced from 56 therms to 10 therms, and to be cost‐
effective only a minimal incentive could be offered which would make this an ineffective 
offering. When presented to the EESC in the October 27 meeting, the Committee had no 
objections to Intermountain’s proposal to retire this rebate (Exhibit No. 4, Page 13).  

Additions:  
The Company proposes the addition of three new rebates to its Residential EE Program. Unless 
specifically stated, all rebate inputs for cost‐effectiveness testing were based on the 2019 CPA.   
 Smart Thermostat – The smart thermostat has consistently been the most frequently requested 
appliance rebate by HVAC contractors, customers, and members of the EESC.  It was also 
included as a recommended program addition in the Company’s EM&V study (see Exhibit No. 5, 
Page 143). The proposed rebate is $100 for a wi‐fi enabled smart thermostat with estimated 
annual savings of 44 therms per appliance. Discussions with the EESC at the September 16 
committee meeting revealed the CPA estimated useful life (EUL) of 8 years for the appliance was 
far too low, and ADM recommended an EUL of 11 years (see Exhibit No. 4, Page 11).  The 
Company believes the smart thermostat will complement other space heating rebates, and 
therefore the Company used a participation estimate of 2,500 thermostat rebates in 2021 for 
cost‐effectiveness testing.  

 Boiler – Based on customer and HVAC contractor feedback, the addition of a residential boiler 
rebate will provide a high‐efficient space heating option for those customers that do not have a 
forced air furnace, and cannot utilize the combination space and water heat system rebate 
because water used for domestic purposes cannot also be used for space heat. The EESC 
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 2 of 9
supported adding this equipment rebate when it was presented at the October 27 meeting (see 
Exhibit No. 4, Page 13). The proposed rebate is for $800, requires a minimum efficiency of 95% 
AFUE, and has an estimated annual savings of 159 therms. As a first time offering, the Company 
estimated 25 rebate applications in 2021 for cost‐effectiveness testing.  

 Tankless Water Heater – Tier II – One of the recommendations of the EM&V study was to 
explore opportunities to add a tankless water heater at a lower price point than the current 
offering (see Exhibit No. 5, Page 143). An additional tankless water heater rebate will provide 
customers another high‐efficient water heating option at a slightly lower estimated incremental 
cost of $1,152 for an 0.87 UEF tankless water heater compared to the 0.91 UEF tankless water 
heater with an estimated incremental cost of $1,800 that is currently included in the Company’s 
program. The proposed rebate is for $300, requires a minimum efficiency of 0.87 UEF, and has 
an estimated annual savings of 58 therms. The Company estimated a participation level of 200 
rebates in 2021 for cost‐effectiveness testing.  

Revisions:  
Intermountain proposes to revise the following four rebates. 
 Storage Water Heater – Based on the 2019 CPA, annual therm savings for this rebate have 
increased from 22 therms to 38 therms while EUL has decreased from 16 years to 13 years.  The 
Company proposes to increase the 0.68 UEF (previously 0.67 EF) water heater rebate from $50 
to $115 and anticipates that this increase will encourage more participation from the 2019 level 
of 8 rebates. The Company estimated 50 rebates in 2021 for cost‐effectiveness testing. The 
efficiency rating will be updated from Energy Factor (EF) to Uniform Energy Factor (UEF) to be 
consistent with the Department of Energy’s industry standard for measuring energy efficiency 
in water heaters. This new standard required new testing procedures that resulted in consistent 
standards for measuring energy efficiency performance, a better reflection of real‐world results 
that impact energy efficiency ratings, apples‐to‐apples‐comparison of water heaters, and a 
simplified water heater selection process.  

 Tankless Water Heater‐Tier I – Based on increased estimated annual therm savings (from 58 to 
65 therms) and increased EUL (from 18 years to 25 years) identified in the CPA, the Company 
proposes to increase this rebate from $150 to $325. Due to offering an additional tankless 
water heating option, the number of rebates estimated for 2021 is lower than the number of 
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 3 of 9
rebates paid in 2019 or during 2020. The Company estimated 100 rebates will be paid in 2021 
for cost‐effectiveness testing. The efficiency rating will be updated from EF to UEF for the 
reasons outlined above.  

 Combination Boiler for Space and Water Heat ‐ This equipment rebate, with a requirement of 
“90% or greater efficiency condensing tankless combo system for space and water heat,” has 
had low participation, 3 and 11 rebates in 2018 and 2019, respectively, and has been one of the 
more misunderstood offerings, both from an equipment standpoint and application standpoint. 
Intermountain has received applications where HVAC contractors have installed two tankless 
appliances, negating the minimum requirement of one appliance serving both space and water 
heat. The Company has also received applications where a boiler was installed, negating the 
tankless requirement. Since a combination system can be served by either a tankless water 
heater, or a combination boiler, the Company proposes to clarify this rebate by requiring a 
combination boiler, designed for both space and water heat.  The proposed rebate is for $800, 
requires a minimum efficiency of 95% AFUE, and has an estimated annual therms savings of 155 
therms.  The Company estimated a participation level of 25 rebates in 2021 for cost‐
effectiveness testing. 

 Whole Home ‐ The new construction rebate, Whole Home, is the Company’s most revised 
rebate offering proposal. Restructuring of the rebate was based on EM&V recommendations to 
increase efficiency requirements to keep up with code improvements and to isolate the therm 
saving features in new construction. The Company also considered therm saving opportunities 
identified in the evaluation of current building practices in the 2019 Idaho Residential Energy 
Code Field Study (see Exhibit No. 8), the energy code requirements that will become effective 
January 2021, and feedback from the EESC.  In addition, Intermountain commissioned a follow‐
up study by ADM to identify potential therm savings of a variety of therm saving requirements 
(see Exhibit No. 8). One of the more significant changes to the rebate is the retirement of the 
Energy Star Certification. The EM&V study recommended removing the ENERGY STAR 
certification requirement as it “seems to be a barrier to builder participation” (Exhibit No. 5, p. 
12). Due to code improvements to be implemented in January 2021, therm savings for the 
proposed offering are reduced from the estimated 274 therm savings identified in the EM&V 
study (see Exhibit No. 5, Page 85). Subsequently the rebate amounts have also been reduced 
from $1,200 to $900 for the proposed Tier I rebate and $700 for the proposed Tier II rebate. 
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 4 of 9
Under the current program, new construction and appliance rebates are mutually exclusive. 
The Company proposes to allow Whole Home participants to layer on the smart thermostat 
and/or water heating rebates to capture additional therm savings. The Company proposes the 
following two‐tiered new construction offering with specific requirements:  

Whole Home Tier I ‐ $900 (Estimated annual therm savings of 161) 
 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 

Whole Home Tier II ‐ $700 (Estimated annual therm savings of 128) 
 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 

Both tiers of the rebate will require the home to be HERS scored, but no specific HERS threshold 
is required. Since the EM&V evaluation found a lower HERS score did not correlate with more 
therm savings and lower HERS scores could be achieved by implementing non‐energy saving 
measures, setting a specific HERS threshold requirement appeared to not be directly related to 
therm savings (see Exhibit No. 5, Page 74). While the HERS score threshold is not related to 
exact therm savings, requiring that the home be HERS scored is important. The HERS score is a 
way for builders to quantify and certify a home’s energy performance, and it is a simple, 
transparent way for consumers to easily compare homes based on energy efficiency 
performance, much like comparing cars based on a miles‐per‐gallon formula. Builders having 
homes HERS scored, one indication of energy efficient home building, is not yet a common 
building practice in Idaho. According to RESNET, in 2019 only 14% of all new home starts 
received a HERS score. Intermountain believes the requirement to have the home HERS scored 
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 5 of 9
will help to educate both customers and builders on energy efficient building. Requiring a HERS 
certificate will also provide an efficient and reliable process for the Company to verify 
compliance with the proposed program requirements that do affect therm savings. A HERS 
score can only be obtained by a certified home energy rater, who is subject to certification, 
quality control, and quality assurance by the governing body RESNET. In addition, the specific 
requirements added to the proposed rebate are all components of a HERS score and will not 
require additional tests be conducted or additional documentation be provided by the builder to 
enable Intermountain to verify that the rebate requirements have been met.  

The proposed specific requirements will be an above‐code stretch for builders since the 2018 
amended IECC Idaho code will require 5 ACH, R‐38 insulation, and 4 CFM25/100 ft2 CFA. 
Standard equipment efficiency for furnaces is still 80% AFUE.  While not a building code 
requirement, the 95% and 97% AFUE furnace requirements proposed by Intermountain are 
significant high‐efficient equipment upgrades from the standard. In the Residential Whole Home 
Modeling Results Memo by ADM, evaluators found “the individual component that contributes 
the largest magnitude of savings is the movement of ducts and air handler to conditioned 
space” (Exhibit 8, page 9). The EESC and the 2019 Idaho Residential Energy Code Field Study 
(Field Study) identified ACH and duct leakage as energy saving opportunities for Idaho 
residential building.  Due to some of the builder challenges inherent in moving HVAC systems to 
conditioned space, and current building practices of locating the furnace in the garage rather 
than in conditioned space, the Company and the EESC agreed it was important to provide 
builders with an option for reducing duct leakage to outside. When moving the entire HVAC 
systems into conditioned space is not an option, an alternative energy saving route is provided 
by setting an above code duct leakage target of “less than 4 CFM25/100 ft2 CFA for duct leakage 
to outside.”  It is important to specify duct leakage to outside (LTO) versus total duct leakage 
(TL). Idaho code currently only tests for total duct leakage. Minimizing total duct leakage allows 
for management of static pressures and controlling designed air flows, which are essentially 
comfort issues. While homeowner comfort is important, leakage to outside keeps 
unconditioned air outside and conditioned air inside, which is an energy saving and cost issue.  

The duct leakage requirement will not only incent energy and cost savings for homeowners, as 
much as 22 therms per home based on statewide annual measure‐level savings according to the 
Field Study (Exhibit No.8, p. 58), but also promote improved building practices in general.  In 
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 6 of 9
addition to the highest total energy and cost savings potential, the Field Study found “reductions 
in duct leakage represent a significant area for improvement and should be given increased 
attention in future training and enforcement” (Exhibit No 8, Page 54) as the majority of 
observations did not meet code requirement.  

Increased air sealing measured by Air Change per Hour (ACH) was the second largest 
incremental savings identified by ADM and contributes 10 to 30% of total household energy 
savings (Exhibit No. 8, Page 9). Tier I will require a more energy efficient air change target of 3 
ACH and Tier II will require 4 ACH. Both proposed ACH requirements are above the 2021 
building code requirement of 5 ACH.  

The next largest contributor of therm savings is ceiling insulation (see Exhibit No. 8, Page 9). 
Only the highest therm saving rebate offering, Tier I, will require the installation of R‐49 ceiling 
insulation. Currently, Idaho Code only requires R‐38 ceiling insulation and only in Climate Zone 
6.  ADM’s analysis found the R‐49 ceiling insulation upgrade, as part of an integrated energy 
efficient home design, contributed an estimated 10 therms to total savings. For those builders 
that do not want to invest in a ceiling insulation upgrade, the Tier II rebate will still provide a 
rebate opportunity for energy efficient home building.   

This two‐tiered approach will provide two rebate options for new construction of energy 
efficient homes. The Tier I whole home rebate has an estimated annual therm savings of 161 
therms, while Tier II has 128 as calculated by ADM (see Exhibit No. 8, page 10).  The EUL of 25 
years and $2,117 estimated incremental cost of energy efficient new construction provided by 
the CPA will be used in cost‐effectiveness calculations. High level calculations estimate that 
retiring the ENERGY STAR certification requirement and instead implementing the specific 
rebate requirements outlined here, are equitable incremental costs. For cost‐effectiveness 
testing, an estimate of 600 rebates each was used for Tier I and Tier II participation. It is 
anticipated that alleviating a market barrier to participation by retiring ENERGY STAR 
certification will result in an increase in participation. The estimate of 1,200 total homes in 2021, 
is conservatively greater than 2019 participation of 1,079 homes, but less than 2020 year‐to‐
date participation numbers.  

Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 7 of 9
Conclusion 
The resulting proposed Residential EE Program, including cost‐effectiveness, can be seen on Exhibit No. 
7, Page 9.  As proposed in the Commercial EE Program filing, the Company estimates that its program 
delivery and administration costs will be approximately $848,000 to be split 80% to the residential 
program and 20% to the proposed commercial program (which is currently before the Commission as 
Case No. INT‐G‐20‐04).  The Company estimates that 2021 rebate costs will be approximately $2.2M as 
seen on Exhibit No. 7, Page 9, Column (h).  Intermountain measures the cost‐effectiveness of the 
proposed program using the Utility Cost Test (UCT).  As seen on Exhibit No. 7, Page 9, Column (i), all 
proposed rebates, as well as the proposed Residential EE Program in total, are cost‐effective with UCT 
ratios of 1 or greater.      
Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 8 of 9
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Exhibit No. 7 Case No. INT-G-20-06 Intermountain Gas Company Page 9 of 9
INTERMOUNTAIN GAS COMPANY’S
REPLY COMMENTS
CASE NO.INT-G-23-06
Attachment 2
Supplement 1 from INT-G-22-03
SUPPLEMENT 1: 2021 COST-EFFECTIVENESS
2021
ANNUAL REPORT
Introduction
Intermountain’s Energy Efficiency Program (EE Program) offers individual customers a way to lower their
usage and monthly energy bills. It additionally benefits all customers by ensuring resources are used
efficiently which delays the need for expensive system upgrades and additional supply contracts,
thereby keeping costs low for everyone. Cost-effectiveness testing is vital to ensuring the Company’s EE
Program is in fact a least-cost resource, and is integral to the design, implementation, and success of the
EE Program.
Cost-Effectiveness and Methodology
Intermountain’s objective is for all rebates to have benefit/cost ratios greater than one for the Utility
Cost Test (UCT). 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, and an annual review.
For a different perspective, cost-effectiveness of rebates is also evaluated based on the customer’s
perspective using avoided supply costs, program administration costs and net participant costs, or the
Total Resource Cost Test (TRC). However, the TRC is not the primary cost test used for decisions
regarding the inclusion or exclusion 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’s (NAPEE) Understanding Cost Effectiveness of Energy Efficiency Programs:
Best Practices, Technical Methods, and Emerging Issues for Policy-Makers.
Rebate characteristics such as estimated useful life, deemed therm savings, and incremental cost used
for cost-effectiveness testing are provided by the CPA study for all rebates, except for Whole Home
rebates. Estimated therm savings for Whole Home rebates are based on the EM&V impact evaluation.
The rebate count used in the cost-effectiveness calculation is the actual number of rebates paid for the
program year.
Cost-effectiveness of EE Program rebates are reviewed annually. The results are reported in the annual
report and reviewed with the Energy Efficiency Stakeholder Committee (EESC). Rebate performance,
cost-effectiveness, market insights, and lessons learned are taken into consideration when deciding
whether to continue, revise or retire a rebate.

1
Assumptions
In calculating cost-effectiveness for each rebate and for the Program as a whole, the Company relied
upon several assumptions as well as studies provided by independent third-party sources. The section
below discusses the key inputs used in calculating cost-effectiveness and the assumptions and sources
used.
Energy Savings
Energy savings for each rebate are calculated by multiplying each rebate’s gross annual therm savings by
the total number of rebates issued. The energy savings are then valuated based on the Company’s
Avoided Cost. The Avoided Cost is used both to economically evaluate the present value of the therms
saved over the life span of the measure and to track the performance of the EE Program. A more in-
depth discussion of the Avoided Cost calculation and its components can be found in Case No. INT-G-22-
03, Exhibit No. 1 which was originally filed as Exhibit No. 5 in Intermountain’s Integrated Resource Plan
(Case No. INT-G-21-06).
Rebate Costs
Total rebate costs are calculated by multiplying the value of each rebate by the number of rebates
issued for the year.
Equipment & Installation Cost
The incremental equipment and installation costs are inputs to the TRC cost test and were provided by
the CPA. These costs represent the incremental purchase and installation costs the participant will pay
between a base case measure and a higher efficient alternative. These costs are not offset by the
amount of the rebate received by the participant.
Program Delivery & Administration
Program delivery and administration costs are direct assigned to their respective program, either
residential or commercial, when they can be specifically identified. For example, the expense of a
residential builder mailing list is charged to Residential Program delivery and administration costs. After
all direct costs are assigned, the remaining pool of program and administration costs, are split between
the residential program and commercial program based on a respective 80/20 split. This ratio is based
on program uptake estimates from the 2019 CPA and is intended to divide costs considering the newly
2
formed commercial program. Within each program, expenses are allocated to each rebate based on the
rebate count as percentage of all rebates. This method ensures that costs are allocated in alignment
with the overall processing and payment work involved for that rebate. Any cost incurred solely for a
particular rebate will be directly assigned to that rebate.
Real Discount Rate
The real discount rate is used to account for the time-value of money and accurately compare costs. The
real discount rate is based on the Company’s tax-affected weighted average cost of capital. The
calculation of the real discount rate can be found in Case No. INT-G-22-03, Exhibit No. 1, Page 11.
Inflation Rate
An inflation assumption is used in cost-effectiveness testing to convert nominal, forward-looking costs
into real dollars. The company assumes an inflation rate of 2.0%.
Net-to-Gross
Net-to-gross (NTG) is a ratio that adjusts the therm savings of rebates and/or programs, so they solely
reflect energy efficiency gains that are the direct result of energy efficiency programs. The NTG deducts
therm savings resulting from free-ridership, or savings that would have occurred regardless of the
program. It also increases therm savings to account for spillover, or savings that occurred but were not
counted by the program, as well as therm savings resulting from market transformation. Unfortunately,
estimates of net savings require making sweeping assumptions to model a theoretical scenario where
the EE Program did not exist. Because of the difficulty in accurately calculating NTG percentages, the
Company used an NTG of 100% for all rebate and program cost-effectiveness analysis. Intermountain
also performs a sensitivity analysis for each rebate that determines the minimum allowable NTG ratio
where the rebate would remain (or become) cost effective under the Utility Cost Test.
Results
The Company performed cost-effectiveness testing at the program level and the individual measure
level. The Residential Program was found to be cost-effective with a UCT of 1.5. The Commercial
Program remains in an awareness-building mode since its launch on April 1, 2021. The UCT of the
Commercial Program was 0.4.

3
EM&V Schedule
The Company prepared a revised EM&V schedule through 2024. The dates on the schedule indicate the
final year of data that will be included in the study. For example, the initial study that was conducted in
2020 used data through the year ended 2019.
The schedule was amended based on the amount of data available for analysis. The impact evaluation
for residential water heating measures was moved to year end 2023 due to the limited number of both
storage and tankless water heater rebates. The Company updated both the storage and water heater
rebates effective April 1, 2021, and uptake has already increased. The impact evaluation planned for
year-end 2022 for commercial kitchen rebates, fryer, griddle, and steamer, was also postponed. Due to
the slow uptake in the Commercial Program, the Company plans to conduct a process evaluation for all
commercial measures for year-end 2023. The Company consulted with the EESC on the revised EM&V
study timing. In the interim years between formal, third-party evaluation, the Company will monitor,
evaluate, and update program incentives with the best data available.

4
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
2021 UCT Results
Rebate
Therm
Savings
Therm
Savings UCT Benefits UCT Costs UCT Ratio
776,887 5,751,082 3,877,857 1.5
5
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
2021 UCT Results
Rebate
Therm
Savings
Therm
Savings UCT Benefits UCT Costs UCT Ratio
8,603 52,864$ 150,317$ 0.4
6
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Whole Home Tier I - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)- Utility Cost -$ -$
Lifetime Energy Savings (therms)- Total Resource Cost -$ -$
Present Value of Energy Savings S -$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 900$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count -
Total Rebate Costs R -$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 2,117$
Total Equipment & Installation Costs I -$
NOTES
Program Delivery & Administration
Overhead Expenses[1]-$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs -$
Total Program Delivery & Administration Costs A -$
7
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Whole Home Tier II - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)33,664 Utility Cost 263,884$ 233,723$ 1.1
Lifetime Energy Savings (therms)841,600 Total Resource Cost 263,884$ 606,394$ 0.4
Present Value of Energy Savings S 263,884$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 700$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 263
Total Rebate Costs R 184,100$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 2,117$
Total Equipment & Installation Costs I 556,771$
NOTES
Program Delivery & Administration
Overhead Expenses[1]25,854$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 23,768$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 49,623$
8
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Furnace - 95% AFUE - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)235,248 Utility Cost 1,599,739$ 1,222,688$ 1.3
Lifetime Energy Savings (therms)4,704,960 Total Resource Cost 1,599,739$ 3,810,416$ 0.4
Present Value of Energy Savings S 1,599,739$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 350$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 2,704
Total Rebate Costs R 946,400$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 1,307$
Total Equipment & Installation Costs I 3,534,128$
NOTES
Program Delivery & Administration
Overhead Expenses[1]265,817$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 10,471$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 276,288$
9
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Combination Boiler - 95% AFUE - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)465 Utility Cost 3,367$ 2,707$ 1.2
Lifetime Energy Savings (therms)10,230 Total Resource Cost 3,367$ 10,873$ 0.3
Present Value of Energy Savings S 3,367$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 800$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 3
Total Rebate Costs R 2,400$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 3,522$
Total Equipment & Installation Costs I 10,566$
NOTES
Program Delivery & Administration
Overhead Expenses[1]295$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 12$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 307$
10
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Boiler - 95% AFUE - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)477 Utility Cost 3,739$ 2,707$ 1.4
Lifetime Energy Savings (therms)11,925 Total Resource Cost 3,739$ 3,805$ 1.0
Present Value of Energy Savings S 3,739$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 800$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 3
Total Rebate Costs R 2,400$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 1,166$
Total Equipment & Installation Costs I 3,498$
NOTES
Program Delivery & Administration
Overhead Expenses[1]295$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 12$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 307$
11
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Storage Water Heater - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)456 Utility Cost 2,253$ 2,606$ 0.9
Lifetime Energy Savings (therms)5,928 Total Resource Cost 2,253$ 5,906$ 0.4
Present Value of Energy Savings S 2,253$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 115$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 12
Total Rebate Costs R 1,380$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 390$
Total Equipment & Installation Costs I 4,680$
NOTES
Program Delivery & Administration
Overhead Expenses[1]1,180$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 46$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 1,226$
12
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Tankless Water Heater Tier I - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)9,230 Utility Cost 72,352$ 60,659$ 1.2
Lifetime Energy Savings (therms)230,750 Total Resource Cost 72,352$ 270,109$ 0.3
Present Value of Energy Savings S 72,352$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 325$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 142
Total Rebate Costs R 46,150$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 1,800$
Total Equipment & Installation Costs I 255,600$
NOTES
Program Delivery & Administration
Overhead Expenses[1]13,959$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 550$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 14,509$
13
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Tankless Water Heater Tier II - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)232 Utility Cost 1,819$ 1,609$ 1.1
Lifetime Energy Savings (therms)5,800 Total Resource Cost 1,819$ 5,017$ 0.4
Present Value of Energy Savings S 1,819$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 300$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 4
Total Rebate Costs R 1,200$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 1,152$
Total Equipment & Installation Costs I 4,608$
NOTES
Program Delivery & Administration
Overhead Expenses[1]393$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 15$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 409$
14
INTERMOUNTAIN GAS COMPANY
Residential Energy Efficiency Program
Smart Thermostat - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)26,224 Utility Cost 113,436$ 119,284$ 1.0
Lifetime Energy Savings (therms)288,464 Total Resource Cost 113,436$ 184,866$ 0.6
Present Value of Energy Savings S 113,436$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Average Rebated Amount[1]98$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 596
Total Rebate Costs R 58,386$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 208$
Total Equipment & Installation Costs I 123,968$
NOTES
Program Delivery & Administration
Overhead Expenses[2]58,590$ [1]Rebates pay the full cost of the individual thermostat up to a maximum of $100.
Direct Costs 2,308$
Total Program Delivery & Administration Costs A 60,898$ [3]Minimum NTG value where rebate remains cost-effective under UCT.
15
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
Condensing Unit Heater - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)- Utility Cost -$ -$
Lifetime Energy Savings (therms)- Total Resource Cost -$ -$
Present Value of Energy Savings S -$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 1,500$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count -
Total Rebate Costs R -$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 2,889$
Total Equipment & Installation Costs I -$
NOTES
Program Delivery & Administration
Overhead Expenses[1]-$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs -$
Total Program Delivery & Administration Costs A -$
16
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
Boiler Reset Control - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)- Utility Cost -$ -$
Lifetime Energy Savings (therms)- Total Resource Cost -$ -$
Present Value of Energy Savings S -$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 350$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count -
Total Rebate Costs R -$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 612$
Total Equipment & Installation Costs I -$
NOTES
Program Delivery & Administration
Overhead Expenses[1]-$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs -$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A -$
17
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
High Efficiency Condensing Boiler - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)4,145 Utility Cost 32,492$ 42,204$ 0.8
Lifetime Energy Savings (therms)103,627 Total Resource Cost 32,492$ 52,164$ 0.6
Present Value of Energy Savings S 32,492$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Average Rebated Amount[1]2,022$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 4
Total Rebate Costs R 8,087$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 4,511$
Total Equipment & Installation Costs I 18,046$
NOTES
Program Delivery & Administration
Overhead Expenses[2]34,118$ [1]Rebates are based on the capacity of the unit.
Direct Costs -$
Total Program Delivery & Administration Costs A 34,118$ [3]Minimum NTG value where rebate remains cost-effective under UCT.
18
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
Fryer - Energy Star Certified - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)2,032 Utility Cost 9,428$ 37,318$ 0.3
Lifetime Energy Savings (therms)24,384 Total Resource Cost 9,428$ 34,318$ 0.3
Present Value of Energy Savings S 9,428$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 800$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 4
Total Rebate Costs R 3,200$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 50$
Total Equipment & Installation Costs I 200$
NOTES
Program Delivery & Administration
Overhead Expenses[1]34,118$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs -$
Total Program Delivery & Administration Costs A 34,118$
19
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
Steamer - Energy Star Certified - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)2,108 Utility Cost 9,781$ 19,259$ 0.5
Lifetime Energy Savings (therms)25,296 Total Resource Cost 9,781$ 18,329$ 0.5
Present Value of Energy Savings S 9,781$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 1,100$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count 2
Total Rebate Costs R 2,200$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 635$
Total Equipment & Installation Costs I 1,270$
NOTES
Program Delivery & Administration
Overhead Expenses[1]17,059$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs -$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 17,059$
20
INTERMOUNTAIN GAS COMPANY
Commercial Energy Efficiency Program
Griddle - Energy Star Certified - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)- Utility Cost -$ -$
Lifetime Energy Savings (therms)- Total Resource Cost -$ -$
Present Value of Energy Savings S -$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Rebate Amount 200$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Rebate Count -
Total Rebate Costs R -$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 360$
Total Equipment & Installation Costs I -$
NOTES
Program Delivery & Administration
Overhead Expenses[1]-$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs -$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A -$
21
INTERMOUNTAIN GAS COMPANY
Energy Saving Kit - 2021 Cost-Effectiveness Results
Benefits Cost-Effectiveness Tests
Annual Energy Savings (therms)318 Utility Cost 1,163$ 51,535$ 0.0
Lifetime Energy Savings (therms)2,862 Total Resource Cost 1,163$ 51,630$ 0.0
Present Value of Energy Savings S 1,163$
Costs Equations & Assumptions
Utility Cost Test = S x NTG ÷ (R + A)
Average Kit Cost 58$ Total Resource Cost Test = S x NTG ÷ (I x NTG + A)
Kit Count 6
Total Kit Costs R 349$ Real Discount Rate 4.68%
Inflation Rate 2.00%
Equipment & Installation Costs Net-to-Gross (NTG)100%
Incremental Cost Per Unit 74$
Total Equipment & Installation Costs I 444$
NOTES
Program Delivery & Administration
Overhead Expenses[1]51,177$ [1]Allocated based on percentage of portfolio rebate count.
Direct Costs 9$ [2]Minimum NTG value where rebate remains cost-effective under UCT.
Total Program Delivery & Administration Costs A 51,186$
22
Energy Efficiency Program 2024 2023 2022 2021 2020 2019 2018
Residential Measures:
  Whole Home I/P
  Whole Home Tier I I/P
  Whole Home Tier II I/P
  Fireplace 70% FE P
  Fireplace 80% AFUE P
  Combination Boiler for Space and Water Heat I/P P
  Furnace I/P I/P
  Boiler I/P
  Storage Water Heater I/P P
  Tankless Water Heater Tier I I/P P
  Tankless Water Heater Tier II I/P
  Smart Thermostat I/P
Commercial Measures:
  Condensing Unit Heater P
  Boiler Reset Control P
  High‐Efficiency Condensing Boiler P
  Fryer P
  Steamer P
  Griddle P
  Pilot: Energy Savings Kit P/I
Evaluation Type: I=Impact, P=Process, O= Other
Program not yet in existence
Measure offering modified
Measure Offering retired
ENERGY EFFICIENCY PROPOSED EM&V SCHEDULE 2018‐2024
For Rebates Issued Through the Year Ended
23