20260506Final_Order_No_37030.pdf

Office of the Secretary
Service Date
May 6,2026
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF INTERMOUNTAIN ) CASE NO. INT-G-26-02
GAS COMPANY'S APPLICATION FOR )
AUTHORITY TO REVISE RATE )
SCHEDULE EE-RS—RESIDENTIAL ) ORDER NO. 37030
ENERGY EFFICIENCY REBATE )
PROGRAM )
On January 16, 2026, Intermountain Gas Company ("Company") applied to the Idaho
Public Utilities Commission("Commission")requesting authority to revise its Rate Schedule EE-
RS—Residential Energy Efficiency Rebate Program ("Application"). Application at 1. The
Company requested an effective date of March 1, 2026.Id.
On February 20,2026,the Commission issued a Notice of Application,Notice of Modified
Procedure, and Notice of Suspension of Proposed Effective Date, establishing a March 26, 2026,
deadline for public and Commission Staff("Staff') comments, an April 16, 2026, deadline for the
Company to file reply comments, and suspending the Company's proposed changes for 30 days
plus five months from the requested effective date,or until the Commission entered an earlier order
accepting, rejecting or modifying the Company's proposed tariff revision. Order No. 36944. No
petitions to intervene were filed.
Based on our review of the record, we issue this Final Order approving the Company's
request to retire its Whole Home Tier I measure and declare that the Company is no longer required
to produce an Evaluation,Measurement, and Verification(`BM&V") study with a billing analysis
for the Whole Home Tier I measure in its next energy efficiency("EE")prudency filing.
BACKGROUND
The Company previously offered to retire its Whole Home Tier I EE rebate measure in its
Petition for Clarification or Reconsideration of Order No. 36797 in Commission Case No. INT-
G-24-05. In that case, the Commission required the Company to include an EM&V study with a
billing analysis for the Company's Whole Home Tier I measure in its next EE prudency filing.
Order No. 36797 at 13. The Commission also directed the Company to request retirement of the
ORDER NO. 37030 1

measure through a separate filing so that interested parties had the opportunity to participate. Order
No. 36860 at 3.
THE APPLICATION
The Company applied for authorization to retire its Whole Home Tier I measure. Id. The
Company represented that the Whole Home Tier I measure was not evaluated in the 2024 EM&V
study due to inadequate data for a meaningful evaluation because of limited customer participation
in the rebate measure. Id. The Company further represented that based on Staff s therm savings
estimates of 62.65 therms, which were included in Staffs Comments in Case No. INT-G-24-05,
the Whole Home Tier I rebate measure was not cost-effective. Id. at 4.
The Company represented that it doubted the prudency of spending money on an EM&V
study on the Whole Home Tier I measure given the uncertainty of sufficient participation levels to
produce statistically significant results and because the Company predicted that the rebate measure
would not be cost-effective under a billing analysis approach.Id. For those reasons, the Company
requested: (1) authorization to retire the Whole Home Tier I measure; (2) approval of the revised
EE-RS—Residential Energy Efficiency Rebate Program ("EE-RS") rate schedule as filed; and (3)
a declaration from the Commission that the Company was no longer required to produce an EM&V
study with a billing analysis for the Whole Home Tier I measure in the Company's next EE
prudency filing.Id. at 5.
STAFF COMMENTS
After reviewing the Application and supporting material, Staff recommended that the
Commission approve the Company's revised EE-RS rate schedule as filed and that the
Commission declare that the Company was not required to produce an EM&V study with a billing
analysis for the Whole Home Tier I measure in the Company's next EE prudency filing. Staff
Comments at 3.
Additionally, Staff outlined its concerns regarding the Company's EE residential program's
cost-effectiveness over the next two years and that Staff believed the Company's 2026 collection
estimate for the EE Rider were overly optimistic. Id. at 3-7.
I. Whole Home Tier I Measure
Based on its review of the Application and supporting material, Staff agreed that it was
unlikely that the Whole Home Tier I measure would be cost-effective.Id. at 2.Thus, Staff believed
ORDER NO. 37030 2

that performing an EM&V study on the measure after it was retired would be an unnecessary
expense.Id.
Staff explained that in Case No. INT G-24-05, Staff believed that the Whole Home Tier I
measure had similar "construction criteria and savings calculation methodologies as the Whole
Home Tier II rebate." Staff Comments at 2. Thus, Staff believed that a 66% savings estimate
determined through a billing analysis for the Whole Home Tier II measure could be used to
estimate the savings of the Whole Home Tier I measure. Id. at 2-3. Staff explained that by using
Staff's recommended 66% deemed savings estimate from Case No. INT-G-24-05, the Company
demonstrated in Response to Staff's First Production Request at No. 1 that the Whole Home Tier
I measure had a Utility Cost Test ratio ("UCT") of 0.6. Staff Comments at 3. Because the Whole
Home Tier I measure had a UCT of 0.6,1 Staff agreed that the measure was unlikely to be cost-
effective. Staff Comments at 3.
II. Remaining Portfolio Cost-Effectiveness
Staff believed that over the next two years there was a risk that the Company's EE
residential program would not be cost-effective. Id. Staff believed that the Company's 2026
forecasts for the residential portfolio measures, provided in Response to Staff's First Production
Request at No. 1, and outlined in the tables below, showed a UCT of 0.8.Id.
Table No. 1: Historical and Future Residential Portfolio Participation
Measure Incentive 2024 Rebate Count1 • Rebate CountRebate Count
Whole Home I $900 35 150
Tankless Tier 1 $325 1,164 1,500 2,000
Furnace* $275 4,032 2,700 2,500
Combi boiler $800 3 5 5
Boiler $800 13 10 10
Storage Tank Water $115 29 10 -
Heater
Whole Home Tier II $700 1,744 250 -
Tankless Tier II $300 4 - -
Smart Thermostat $100 3,389 700 -
Total 14
1 A measure with a UCT of 1.0 or higher would be considered cost-effective.
ORDER NO. 37030 3

* Rebate decreased to $275 from $350 l/l/2026—2026 forecasts represent a combination of
remaining old rebate payouts and new rebates.
Proposed retirement- expect to accept rebates until 9/2026
Retired as of 12/31/2025 - rebates accepted until 3/21/2026
Table No. 2: Historical and Future Residential Portfolio Savings and Cost-Effectiveness
Cost-
EffectivenessTotal Therm Savings
IVA Incentive 1 16 Therm_�2027 Therm1 1 • 1
Savings Savings Savings
Whole Home I $900 1,995 9,450 - 0.6 0.6 -
Tankless Tier I $325 75,660 75,375 100,500 1.7 1.1 1.1
Furnace* $275 225,792 85,800 80,000 1.2 0.7 0.9
Combi boiler $800 465 841 841 1.8 2.0 2.3
Boiler $800 2,067 1,071 1,071 2.0 1.3 1.5
Storage Tank Water $115 1,102 250 - 1.3 0.7 -
Heater
Whole Home Tier $700 99,408 9,500 - 0.8 0.5 -
II
Tankless Tier II $300 232 - - 1.6 - -
Smart Thermostat $100 149,116 19,600 - 1.5 0.8 -
Total 555,837 1 ..
Id. at 4. Staff reasoned that even though the Company's residential portfolio was expected to have
a UCT of 1.0 by the end of 2027, Staff was concerned that(1) all savings were from the Furnace
and Tankless Water Heater measures and (2) if there was a deviation from the Company's 2026
forecasts, then the portfolio measures were at risk of having a UCT below 1.0.Id. at 3-4.
Staff was also concerned that the Company's Furnace measure was at risk of not meeting
forecasted savings, which could bring the entire residential portfolio's cost-effectiveness below
1.0 because a large portion of the portfolio savings are dependent on the savings from the Furnace
measure. Id. at 5. Staff believed that the retirement of the Whole Home Tier I measure would not
significantly impact the cost-effectiveness of the Tankless Water Heater measure.Id. at 5-6. Staff
stated it would continue to monitor the cost-effectiveness of the Company's residential program in
future DSM prudence filings by the Company.Id. at 4.
III. Financial Review
Staff believed that the Company's estimate that the EE Rider would collect $3,668,745 in
2026, which was supplied to Staff in the Response to Staff's First Production Request at No. 1,
ORDER NO. 37030 4

was overly optimistic when compared to historical data. Staff Comments at 6. Staff believed it was
unlikely that 2026 would collect more than 2024, even if funding increased because of population
growth, because the Company's 2026 collection estimates were more than what was collected in
2024 when the Company's rate was higher.Id. at 6-7.
Staff believed that the Company's projected $1,713,150 in residential rebate expenditures
in 2026 was reasonable due to the fact the Company was working to retire the Whole Home Tier I
measure and"the Storage Tank Water Heater,Whole Home Tier II,Furnace,Tankless Water Heater
Tier II, and Smart Thermostat measures."Id. at 7. Staff believed that there could be an increase in
the residential EE Rider balance in 2026 because of the reduction in rebate expenses. Id. Staff
stated it would continue to monitor the residential EE Rider's balance in future filings.Id.
COMMISSION FINDINGS AND DECISION
The Commission has jurisdiction over the Application and the issues in this case under
Title 61 of the Idaho Code including,Idaho Code §§ 61-501, -502, and -503. The Commission is
empowered to investigate rates, charges, rules, regulations, practices, and contracts of all public
utilities and to determine whether they are just, reasonable, preferential, discriminatory, or in
violation of any provisions of law, and to fix the same by order. Idaho Code §§ 61-501, -502, and
-503.
The Commission has reviewed the Company's Application including all submitted
materials and Staff comments. Based on our review of the record, we find it fair, just, and
reasonable to authorize the Company to retire its Whole Home Tier I measure, to approve the
revised EE-RS rate schedule as filed, and to declare that the Company is not required to produce
an EM&V study with a billing analysis for the Whole Home Tier I measure in its next EE prudency
filing. The Commission finds it is not likely that the Whole Home Tier I measure will be cost-
effective because the Company's calculations show, by using Staff s recommended 66% deemed
savings estimate from Case No. INT-G-24-05, that the measure would only have a UCT ratio of
0.6. Because the UCT ratio was not 1.0 or higher, the measure is not considered cost-effective.
Because we authorize the Company to retire the measure, we find that requiring the Company to
produce an EM&V study with a billing analysis for the measure in its next EE prudency filing
would be an unnecessary expense for the Company and its customers.
ORDER NO. 37030 5

The Commission encourages the Company to continue exploring all cost-effective EE
measures. It is important that measures and incentives are properly aligned with the needs of
customers, and it is equally important that the costs of offering those measures accurately reflect
the energy savings derived from the measure.
ORDER
IT IS HEREBY ORDERED that the Company is authorized to retire its Whole Home Tier
I measure.
IT IS FURTHER ORDERED that the Company's revised EE-RS rate schedule is approved
as filed.
IT IS FURTHER ORDERED that the Company is no longer required to produce an EM&V
study with a billing analysis for the Whole Home Tier I measure in the Company's next EE
prudency filing.
THIS IS A FINAL ORDER. Any person interested in this Order may petition for
reconsideration within 21 days of the service date of this Order regarding any matter decided in
this Order.Within seven days after any person has petitioned for reconsideration, any other person
may cross-petition for reconsideration.Idaho Code § 61-626.
ORDER NO. 37030 6

DONE by Order of the Idaho Public Utilities Commission at Boise, Idaho this 6th day of
May, 2026.
G
EDWARD LODGE, PR VDENT
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JO R. HAMMOND JR., COMMISSIONER
DAYN HA DIE, COMMISSIONER
ATTEST:
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Monic B'aTt1`oWmchez
Commission Secretary
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ORDER NO. 37030 7