APPLICATION

CERTIFICATE OF ATTORNEY

ASSERTION THAT INFORMATION CONTAINED IN AN IDAHO PUBLIC UTILITIES
COMMISSION FILING IS PROTECTED FROM PUBLIC INSPECTION

Idaho Power Company’s Annual Compliance Filing to Update the Load and Gas
Forecast in the Incremental Cost Integrated Resource Plan Avoided Cost Model

Case No. IPC-E-26-30

The undersigned attorney, in accordance with Commission Rules of Procedure 67,
believes that the Attachment 1 to Idaho Power Company’s Annual Compliance Filing
dated October 15, 2026, contains information that Idaho Power and/or a third-party claim
constitutes trade secrets or other confidential business data exempt from disclosure
under Idaho Code § 74-101, et seq., and/or § 48-801, et seq. As such, it is protected from
public disclosure, inspection, examination, or copying.

DATED this 15th day of October 2026.

LISA C. LANCE
Counsel for Idaho Power Company

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 1
LISA C. LANCE (ISB No. 6241)
DONOVAN E. WALKER (ISB No. 5921)
Idaho Power Company
1221 West Idaho Street (83702)
P. O. Box 70
Boise, Idaho 83707
Telephone: [phone]
Facsimile: [phone]
[e-mail]
[e-mail]

Attorneys for Idaho Power Company

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION

IDAHO POWER COMPANY’S ANNUAL
COMPLIANCE FILING TO UPDATE THE
LOAD AND GAS FORECASTS IN THE
INCREMENTAL COST INTEGRATED
RESOURCE PLAN AVOIDED COST
MODEL.

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CASE NO. IPC-E-26-30

IDAHO POWER COMPANY’S
ANNUAL COMPLIANCE FILING

Idaho Power Company (“Idaho Power” or “Company”) hereby respectfully submits
to the Idaho Public Utilities Commission (“Commission”) this filing in compliance with
Order Nos. 32697 and 32802 to update the load forecast, natural gas forecast, and long-
term contract changes used in the Incremental Cost Integrated Resource Plan (“ICIRP”)
avoided cost methodology. Additionally, in compliance with Order No. 36885, this filing
confirms the Peak Hour and Premium Peak Hours used to calculate capacity payments
for energy storage qualifying facilities (“QF”).

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 2
I. INTRODUCTION
In Order No. 32697, the Commission determined that the inputs to the ICIRP
avoided cost methodology, utilized for all proposed Public Utility Regulatory Policies Act
of 1978 ("PURPA") QF projects that exceed the published rate eligibility cap, will be
updated every two years upon acknowledgement of the utility's Integrated Resource Plan
(“IRP") filing, with the exception of the load forecast and the natural gas forecast, which
should be updated annually. Discussing the timetable for updates to the ICIRP
Methodology, the Commission explained:
We find that, in order to maintain the most accurate and up-
to-date reflection of a utility's true avoided cost, utilities must
update fuel price forecasts and load forecasts annually —
between IRP filings…In addition, it is appropriate to consider
long-term contract commitments because of the potential
effect that such commitments have on a utility's load and
resource balance…We further find it appropriate to consider
PURPA contracts that have terminated or expired in each
utility's load and resource balance. We find it reasonable that
all other variables and assumptions utilized within the IRP
Methodology remain fixed between IRP filings (every two
years).1

Though the Commission originally set June 1 as the annual filing date, it agreed
on reconsideration that updates to gas and load forecasts used in the ICIRP
methodologies should occur on October 15 of each year.2 Additionally, the Commission
further clarified in Order No. 36956 that the Company should use the “most recently filed
IRP to determine the avoided cost of energy and the avoided cost of capacity for ICIRP
pricing.”3

1 In the Matter of Generic Electric – Phase Three – Analyzing SAR and IRP Methodologies, Case No.
GNR-E-11-03, Order No. 32697 at 22 (Dec. 18, 2012).
2 Id., Order No. 32802 at 3 (May 6, 2013).
3 In the Matter of Idaho Power Company’s Application for Approval or Rejection of an Energy Sales
Agreement with Fossil Gulch Wind Park, LLC for the Sale and Purchase of Electric Energy from the Fossil
Gulch Wind Park, Case No. IPC-E-25-31, Order No. 36956 (March 5, 2026).

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 3
In considering implementation of PURPA with respect to energy storage QFs, the
Commission determined that the avoided cost of capacity should be paid only on
production during the hours identified as the Company's Peak Hours and Premium Peak
Hours.4 The Commission also agreed that the updates to Peak and Premium Peak Hours
should be included in the annual October 15 update to the other ICIRP method inputs.5
The load forecast, natural gas forecast, contract information, and Peak Hours and
Premium Peak Hours designations for battery storage capacity payments that are set
forth below are presented in compliance with the pertinent Commission Orders and will
be incorporated into Idaho Power's ICIRP avoided cost methodology. Consistent with the
Commission's directives, this methodology will be used by Idaho Power as the starting
point for the negotiation of its contractual avoided cost rates as of January 1, 2027.
II. LOAD FORECAST
Consistent with prior updates, Idaho Power is updating its load forecast to the
Company’s most recent available 50th percentile forecast. Idaho Power's most recent
load forecast from September 2026 shows an increase in customer loads over the 20-
year period, as compared with the September 2025 load forecast used in the Company's
previous annual update approved in December 2025.6 The increase is due to the
Company's re-estimation of all major retail customer class usage and growth as well as
updates related to electric service agreements and special contracts to include the most
recent assessment of load and energy requirements by those customers. The updated
load forecast and a comparison to the September 2025 load forecast is included in

4 In the Matter of Idaho Power Company’s Petition to Establish Avoided Cost Rates – PURPA Energy
Storage Qualifying Facilities, Case No. IPC-E-20-02, Order No. 34794 (Oct. 2, 2020).
5 Id., Order No. 34913 (Feb. 5. 2021).
6 In the Matter of Idaho Power Company's Annual Compliance Filing to Update the Load and Gas
Forecasts in the Incremental Cost Integrated Resource Plan Avoided Cost Model, Case No. IPC-E-25-33,
Order No. 36885 (Dec. 23, 2025).

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 4
Confidential Attachment 1. This information is being marked and treated as confidential
because it is confidential and proprietary Company information that has not yet been
shared publicly.
III. NATURAL GAS PRICE FORCAST
The Company is proposing to use New York Mercantile Exchange (“NYMEX”)
forward natural gas prices7 for the first three years of the natural gas price forecast.
Additionally, the Company proposes that the fourth year of the natural gas price forecast
consist of the average of the NYMEX forward price and the S&P Platt’s long-term natural
gas forecast8 (“Platt’s forecast”), and that the forecast for the fifth year and beyond rely
on the Platt’s forecast.
The Company’s proposal to rely on NYMEX prices for years one through three is
consistent with Idaho Power’s risk management policy. In July 2025, the Company
extended its hedging horizon under the policy from 18 to 36 months. Because NYMEX-
based hedges comprise the majority of the Company’s natural gas hedging activity,
NYMEX prices are representative of the Company's gas price exposure over this three-
year period. The Company’s proposal herein is also consistent with prior Commission
direction. For example, in Order No. 36885 regarding the Company’s 2025 update, the
Commission directed the Company to utilize the same methodology the Company is
proposing now for the 2026 update: the most recent NYMEX forward prices for the first
three years of the forecast, an average of the NYMEX forward price and the Platt’s
forecast in year four, and the Platt’s forecast in year five and thereafter.9

7 Published October 12, 2026.
8 Published August 28, 2026.
9 Order No. 36885 at 8.

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 5
Because the forecasted prices contained in the Company’s proposal come from
subscription-based and proprietary sources, this information has been included in
Confidential Attachment No. 1, which contains a table and a graph setting forth the natural
gas price forecast proposed in this case compared with the Company’s natural gas price
forecast approved in last year’s annual compliance filing through Order No. 36885.
IV. CONTRACT TERMINATIONS, EXPIRATIONS, AND ADDITIONS
Idaho Power currently has eight non-PURPA, long-term power purchase
agreements with projects that are online: Elkhorn Valley Wind (101 megawatts ("MW")),
Raft River Geothermal (13 MW), Neal Hot Springs Geothermal (22 MW), Jackpot Solar
(120 MW), Black Mesa Energy Solar (40 MW), Franklin Solar (100 MW), Pleasant Valley
Solar 1 (200 MW), and Pleasant Valley Solar 2 (125 MW). The Company has one non-
PURPA long term battery services agreement with an operational battery energy storage
system ("BESS"), the Kuna BESS (150 MW/600 MWh). Idaho Power also has 129
contracts with online PURPA QFs with a total nameplate capacity of 1,119 MW.
Moreover, the Company has four additional non-PURPA PPAs with solar facilities that
have not yet achieved commercial operation, and two additional long-term battery
services agreements with BESS facilities that have not yet achieved commercial
operation.
Table 1 below provides a list of new and terminated contracts since the last update
in October 2025. New Energy Sale Agreements (“ESA”) and terminated or expired
contracts, as well as new complete ESA applications, are all included in the ICIRP model
on a continuous basis. New and Commission-approved non-PURPA power purchase
agreements or resource acquisitions are also included in the model on a continuous
basis.

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 6
Table 1: Contract Updates

V. PEAK AND PREMIUM PEAK HOURS
In Order No. 36885, the Commission approved the Company’s proposal to rely on
the Loss of Load Probability (“LOLP”) method to identify Peak and Premium Peak Hours
going forward.10 The LOLP methodology, which has been implemented in Idaho Power's
past three IRP filings via the internally developed Reliability & Capacity Assessment Tool,
calculates the probability of demand exceeding available generation for every hour over
the planning period. Capacity-based hourly LOLP values are currently used to determine
the seasons and hours of highest risk, as described in Appendix D of the 2025 IRP. These
hours represent the greatest risk of capacity shortfall and are therefore the most
appropriate for identifying Peak and Premium Peak Hours for battery storage capacity
payments.

10 Order No. 36885 at 8.

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 7
The Company’s proposal to use the LOLP methodology to determine Peak and
Premium Peak Hours was based on the objective, data-driven nature of the analysis and
the fact that use of the methodology to determine risk timing is consistent with Idaho
Power’s approach in other proceedings. The Commission agreed, finding the method to
be “more sophisticated and objective” and “consistent with the methods used to calculate
avoided capacity costs in the export credit rate for on-site generation customers and to
set Time-of-Use customer rates.”11
The LOLP-based timing of highest risk study is updated every two years as part of
each IRP filing. The currently effective Peak and Premium Peak Hours approved in Order
No. 36885 were the result of the timing of highest risk study performed for the 2025 IRP;
the Company has not run an updated study or filed a new IRP since that time. Therefore,
the Company is not proposing a change to the current Peak and Premium Peak Hours in
this filing.
In sum, the Peak and Premium Peak Hours are now identified based on the highest
risk hours identified in the LOLP-based study, updated every two years as part of each
IRP filing. As a result, both the methodology for determining Peak and Premium Peak
Hours, and the timing of the determination, have changed since Order No. 34913 when
the Commission first directed the Company to update such hours in the annual October
15 filing. In light of these changes, Idaho Power proposes that in the future it will expressly
identify the Peak and Premium Peak Hours in the IRP itself, and that the update to the
hours would take effect as of the filing of each IRP. This proposal would (1) align the
adoption of the updated Peak and Premium Peak Hours with filing of the timing of highest
risk study and IRP that determines the hours, and (2) align the adoption of the updated

11 Id. at 7.

IDAHO POWER COMPANY’S ANNUAL COMPLIANCE FILING - 8
Peak and Premium Peak Hours with the adoption of other avoided cost pricing inputs that
are updated with the filing of each IRP.12 This proposed implementation would support
consistency between the filings and avoid a timing lag that would otherwise exist between
the filing of a new IRP and the update of the Peak and Premium Peak Hours in the annual
October 15 update filing, as is currently expected. In the alternative, Idaho Power could
continue to provide the updated hours as part of this annual compliance filing for
Commission approval.
VI. CONCLUSION
Idaho Power hereby respectfully submits this updated load forecast, natural gas
forecast, contract information, and validated Peak and Premium Peak Hours in
compliance with the Commission's directives in Order Nos. 32697, 32802, and 36885 and
requests that the Commission accept and approve the same.
Respectfully submitted this 15th day of October 2026.

LISA C. LANCE
Attorney for Idaho Power Company

12 For example, the avoided cost pricing model used in the ICIRP methodology is updated as of the filing
of each new IRP.
BEFORE THE

IDAHO PUBLIC UTILITIES COMMISSION

CASE NO. IPC-E-26-30

IDAHO POWER COMPANY

CONFIDENTIAL ATTACHMENT NO. 1

ATTACHMENT 1
IS CONFIDENTIAL AND WILL BE PROVIDED TO THOSE PARTIES THAT EXECUTE
THE PROTECTIVE AGREEMENT IN THIS MATTER