20251231Final_Order_No_36890.pdf

Office of the Secretary
Service Date
December 31,2025
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF ROCKY MOUNTAIN ) CASE NO. PAC-E-25-19
POWER'S APPLICATION TO UPDATE )
LOAD AND GAS FORECASTS USED IN THE )
INTEGRATED RESOURCE PLAN AVOIDED ) ORDER NO. 36890
COST MODEL )
On October 15, 2025, Rocky Mountain Power, a division of PacifiCorp ("Company"),
applied to the Idaho Public Utilities Commission("Commission") for approval of an updated load
forecast, an updated natural gas price forecast, and contract changes used as inputs in the
Company's Integrated Resource Plan ("IRP") avoided cost model calculations for qualifying
facilities("QFs")under the Public Utility Regulatory Policies Act of 1978 ("PURPA")as required
by Order Nos. 32697 and 32802 ("Application"), with an effective date of January 1, 2026.
On November 4, 2025, the Commission issued a Notice of Application and Notice of
Modified Procedure establishing public comment and Company reply deadlines. Order No. 36831.
Commission Staff("Staff") filed the only comments.
Having reviewed the record, the Commission issues this Order approving the Company's
Application.
BACKGROUND
Pursuant to the PURPA and the Federal Energy Regulatory Commission's ("FERC")
implementing regulations, this Commission has approved the IRP Methodology to calculate
avoided cost rates for QFs that are above the resource-specific project eligibility cap. QFs that are
below the applicable project eligibility cap are eligible to receive published avoided cost rates
calculated using the surrogate avoided resource("SAR Method").See Order No. 32697 at 7-8. The
avoided cost rate is the purchase price paid to QFs for the energy, or the energy and capacity, that
the QF provides to the utility. 18 C.F.R. § 292.10 1(b)(6)(defining "avoided cost"). To ensure that
avoided costs most accurately reflect the utility's marginal cost of energy or capacity, the
Commission has directed utilities to "update fuel price forecasts and load forecasts annually —
between IRP filings," and to update the Commission about its "long-term contract commitments
because of[their] potential effect . . . on a utility's load and resource balance." Order No. 32697
at 22.
ORDER NO. 36890 1

THE APPLICATION
Under Order No. 32697, the Company must update its IRP Methodology calculation to
ensure accurate avoided costs for new, eligible PURPA QFs. Application at 1-2. The Company
stated that these forecasts are to be updated biennially(after the acknowledgement of the IRP),but
that load and natural gas forecasts are to be updated annually.Id. at 2.
The Company explained that the reduction in the load forecast from the June 2024 long-
term forecast to the December 2024 forecast is primarily due to the exclusion of large prospective
data center loads and the Kennecott load, which was not under contract at the time the 2025 IRP
was developed. Id. at 3.
The Company stated that its most recent Official Forward Price Curve ("OFPC") was
finalized on September 30, 2025. Id. at 5. The Company noted that gas prices in the OFPC are
generally lower over the next three years, slightly higher from 2030 through 2037 except for Opal
gas, and lower after 2038 for all hubs except Stanfield. Id.
The Company reported that it entered 15 long-term contracts, including 10 long-term QF
contracts, totaling 797 MW of nameplate capacity, and that one long-term contract with 280 MW
of nameplate capacity was terminated.Id. at 7. The Company is currently party to 43 non-PURPA
long-term power purchase agreements totaling 4,864 MW and 170 PURPA QF projects totaling
2,215 MW of nameplate capacity. Id.
STAFF COMMENTS
After reviewing the Application, Staff recommended approval of the proposed load
forecast and natural gas price forecast, effective January 1, 2026. Staff Comments at 2.
I. Load Forecast
Staff compared the proposed load forecast with the forecast approved in last year's annual
update (Case No. PAC-E-24-12) and found the proposed forecast reasonable. Id. The Company
initially stated that the lower forecast submitted in this resulted from exclusion of large new data
center loads and the Kennecott load. Id. However, the Company later clarified that the Kennecott
load was excluded from both forecasts and therefore did not contribute to the difference. Id. The
Company explained that the primary change reflects the exclusion of large new customers that will
self-supply their resources and transmission, eliminating the need for the Company to serve that
load.Id.
ORDER NO. 36890 2

Staff found it reasonable to exclude these customers from the load forecast,if the associated
resources are also excluded from the IRP model when calculating avoided cost rates for IRP-based
contracts. Id. at 3. For purposes of this proceeding, Staff recommended that the Commission
approve the proposed load forecast effective January 1, 2026. Id.
II. Natural Gas Price Forecast
The Company's natural gas price forecast is based on a combination of forward market
prices and fundamentals-based projections. Id. For the first 36 months, the forecast relies entirely
on forward prices; months 37 through 48 blend the prior year's forward prices with a
fundamentals-based forecast; and months 48 and beyond rely solely on a Siemens-developed
fundamentals forecast.Id.
Because IRP-based PURPA contracts are limited to two years, Staff focused its review on
near-term prices. Id. Staff compared the proposed Henry Hub forecast with forecasts from Case
No. AVU-E-25-13 and NYMEX forward prices published on October 15, 2025. Id. As the near-
term forecasts are consistent across these sources, Staff found the proposed gas price forecast
reasonable. Id.
III.Contract Changes
Contract updates are incorporated into the IRP model on an ongoing basis. Id. at 4.
However, the annual filing provides the Commission with an opportunity to review and monitor
those updates. Id. Since last year's annual update filing, the Company has executed fifteen long-
term contracts totaling 797 MW and terminated one long-term contract totaling 280 MW.Id. Staff
found these contract changes to be accurate.Id.
COMMISSION FINDINGS AND DECISION
The Commission has jurisdiction over this matter under Idaho Code §§ 61-501 through
503. The Commission is empowered to investigate rates, charges,rules,regulations,practices, and
contracts of public utilities and to determine whether they are just, reasonable, preferential,
discriminatory, or in violation of any provision of the law, and to fix the same by order. Idaho
Code §§ 61-502 and -503. Additionally, the Commission has authority under PURPA and FERC
regulations to set avoided costs, to order electric utilities to enter fixed-term obligations for
purchase of energy from QFs, and to implement FERC rules. The Commission may enter any final
order consistent with its authority under Title 61, Idaho Code, and PURPA.
ORDER NO. 36890 3

Under this authority, we have reviewed the record, including the Application and Staff s
comments. We find that the Application complies with our directives in Order Nos. 32697 and
32802. The load growth and natural gas price forecasts are reasonable as filed given the
information available at this time. The Commission further finds that all contract changes, as filed,
are reasonable.
ORDER
IT IS HEREBY ORDERED that the Company's annual updates to its energy load and
natural gas price forecasts are reasonable and approved, effective as of January 1, 2026.
THIS IS A FINAL ORDER. Any person interested in this Order may petition for
reconsideration within twenty-one (21) days of the service date of this Order about any matter
decided in this Order. Within seven (7) days after any person has petitioned for reconsideration,
any other person may cross-petition for reconsideration. See Idaho Code § 61-626.
DONE by Order of the Idaho Public Utilities Commission at Boise, Idaho this 3 1" day of
December 2025.
G
Gw
EDWARD LODGE, IykESVNT
R. HAMMOND JR., COMMISSIONER
YN HARDI , COM SSIONER
ATTEST:
?4UO A -
La ra Calderon Robles
Interim Commission Secretary
I:\Legal\ELECTRIC\PAC-E-25-19_L and G\orders\PACE2519_final_em.doox
ORDER NO. 36890 4