20251229Final_Order_No_36887.pdf

Office of the Secretary
Service Date
December 29,2025
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF AVISTA ) CASE NO. AVU-E-25-13
CORPORATION'S ANNUAL COMPLIANCE )
FILING TO UPDATE THE LOAD AND GAS ) ORDER NO. 36887
FORECASTS IN THE INCREMENTAL COST )
INTEGRATED RESOURCE PLAN AVOIDED )
COST MODEL TO BE USED FOR AVOIDED )
COST CALCULATIONS )
On September 15, 2025, Avista Corporation ("Company") filed a compliance filing
("Filing") requesting the Idaho Public Utilities Commission ("Commission") issue an order
accepting its updated load forecast, natural gas price forecast, and contracts used as inputs to
calculate its incremental cost Integrated Resource Plan ("IRP") avoided cost rates, as required by
Order Nos. 32697, 32802, and 35274. The Company requests a January 1, 2026, effective date.
On October 9, 2025, the Commission issued a Notice of Filing and Notice of Modified
Procedure, setting deadlines for interested parties to file comments and for the Company to reply.
Order No. 36792. Commission Staff("Staff") filed the only comments.
BACKGROUND
IRP avoided cost rates are available to qualifying facilities ("QFs") that are above the
resource-specific project eligibility cap for published avoided cost rates under Idaho's
implementation of the Public Utility Regulatory Policies Act of 1978 ("PURPA"). Pursuant to the
PURPA and 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 Methodology"). 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. § 292.101(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
ORDER NO. 36887 1

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.
THE FILING
The Filing presents the Company's projected load forecast as of May 13, 2025, for the next
twenty years, in the following Table 1:
Table 1:Enern Load Forecast
Year Energy
(aMW)
2026 1,169
2027 1,178
2028 1,186
2029 1,202
2030 1,202
2031 1,203
2032 1,204
2033 1,214
2034 1,225
2035 1,237
2036 1,248
2037 1,266
2038 1,285
2039 1,301
2040 1,320
2041 1,345
2042 1,362
2043 1,386
2044 1,406
2045 1,424
The Company stated its natural gas forecast was developed using a "blend of two national
forecasting consultant's [sic] most recent forecasts,the U.S. Energy Information Administration's
Annual Energy Outlook..., and forward market prices as of June 20, 2025." Filing at 3. Since its
2024 filing, the Company has not executed any new PPAs or new long-term PURPA contracts.
Two existing PURPA contracts, Meyers Falls and Sheep Creek, are in their final year and are
currently under negotiation.
PUBLIC COMMENTS
The Commission received one public comment in opposition to the Filing. The commentor
argued that the Filing was based on inflated gas prices, inadequate load mitigation, and secretive
contracts, which all risked higher rates without commensurate benefits.
STAFF COMMENTS
After reviewing the Filing, Staff recommended Commission approval of both the proposed
load forecast and the proposed natural gas price forecast,with an effective date of January 1,2026.
Staff Comments at 4.
ORDER NO. 36887 2

I. Load Forecast
Staff compared the Company's proposed load forecast with the Commission-approved load
forecast from last year's annual update proceeding. Id. at 2. Like last year's filing, the Company
prepared its medium-term forecast(2026-2029) using an econometric approach and its long-term
forecast(2030-2045)using end-use modeling, consistent with last year's methods. The Company
reported no significant changes in customer growth or key assumptions, including electrification
trends, since its last filing. Accordingly, Staff found the proposed load forecast reasonable. Id.
II. Gas Price Forecast
The Company's gas price forecast blends the New York Mercantile Exchange("NYMEX")
forward market, the Energy Information Administration's (`EIA") Annual Energy Outlook, and
two consultant forecasts. Id. at 2-3. The blending method initially relies on forward prices
exclusively and gradually shifts to the EIA average and two consultant forecasts for later years.Id.
at 3.
As PURPA contracts are limited to two years, Staff reviewed the near-term Henry Hub
forecast, comparing it with the one presented in Case No. PAC-E-25-19 and the October 15, 2025,
NYMEX prices. Id. These forecasts were similar, so Staff found the Company's proposed gas
price forecast reasonable. Id.
III.Contract Changes
There have been no contract changes since the Company's last compliance filing. Staff
noted that contract updates are continuously incorporated into the IRP model. The annual filing
allows the Commission to review and monitor these updates.Id. at 4.
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 law, and to fix the same by order.Idaho Code §§
61-502 and-503. In addition, the Commission has authority under PURPA and FERC regulations
to set avoided costs, to order electric utilities to enter fixed-term obligations for the purchase of
energy from QFs, and to implement FERC rules. The Commission may enter any final order
consistent with its authority under Title 61 and PURPA.
ORDER NO. 36887 3

Pursuant to this authority, we have reviewed the record in this case including the Filing
and all submitted comments. We find that the Filing complies with our directives in Order Nos.
32697, 32802, and 35274. We,therefore, approve the Company's annual updates contained in the
Filing.
ORDER
IT IS HEREBY ORDERED that the Company's annual updates to its energy load, natural
gas price forecasts, and contracts discussed above are reasonable and approved, effective 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.Idaho Code § 61-626.
DONE by Order of the Idaho Public Utilities Commission at Boise, Idaho this 29th day of
December 2025. /
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DWARD LODGE, RE 'I ENT
HN R. HAMMOND JR., COMMISSIONER
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DA-MHARDIVCOMMfSSIONER
ATTES
La a Calderon Robles
Interim Commission Secretary
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ORDER NO. 36887 4