20260731Application.pdf

I ,1
Avista Corp. RECEIVED
1411 East Mission P.O. Box 3727 JULY 31, 2026
Spokane, Washington 99220-0500 IDAHO PUBLIC
Telephone [phone] UTILITIES COMMISSION
Toll Free 800-727-9170
July 31, 2026
Commission Secretary
State of Idaho
Idaho Public Utilities Commission
11331 W. Chinden Blvd. Building 8, Suite 201-A
Boise, Idaho 83702-5983
RE: Case No. AVU-E-26-05
Power Cost Adjustment (PCA)Annual Rate Adjustment Filing of Avista Corporation
Dear Commission Secretary:
Attached for electronic filing with the Commission is the annual Power Cost Adjustment Rate
Filing.' The Company requests that the Commission issue an order approving recovery of power
costs deferred for the period July 1, 2025 through June 30, 2026, and approving a PCA surcharge
of 0.1570 per kilowatt-hour to be effective October 1, 2026.
Under the Company's proposal, the PCA rebate rate for all customers, including residential
customers, would increase from an existing rebate rate of 0.3010 per kilowatt-hour to a proposed
surcharge rate of 0.1570 per kilowatt-hour, or an increase in the rate of 0.4580 per kilowatt-hour.
Since PCA rate adjustments are spread on a uniform cents per kilowatt-hour basis, the resulting
percentage change varies by rate schedule. The overall increase is approximately$14.6 million or
4.2%. Residential customers using an average of 939 kilowatt-hours per month would see their
monthly bills decrease from $119.52 to $123.83, an increase of$4.31 per month, or 3.6%.
Certain supporting documents are CONFIDENTIAL, rendering these documents exempt from
public inspection, examination and copying pursuant to Sections 74-101 through 74-126 of the
Idaho Code. Avista believes that the identified CONFIDENTIAL supporting documents contain
valuable commercial information.
As such, Avista is submitting a separate electronic filing containing the electronic form of the
CONFIDENTIAL supporting documents, in compliance with Rule 067.02.b.
' Case No. GNR-U-20-01,Order No. 35375

Please direct any questions regarding this filing to Ryan Finesilver at
Eyan.finesilvergavistacorp.com and (509) 495-4873 or Annette Brandon at
[e-mail] or(509) 495-4324
Sincerely,
/s/ Patrick EArbar
Patrick D. Ehrbar
Director of Regulatory Affairs
Enclosures

ANNI GLOGOVAC
COUNSEL FOR REGULATORY AFFAIRS
AVISTA CORPORATION
1411 E. MISSION AVENUE
P.O. BOX 3727
SPOKANE, WASHINGTON 99220
PHONE: [phone]
[e-mail]
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE POWER COST )
ADJUSTMENT (PCA) ANNUAL RATE ) CASE NO. AVU-E-26-05
ADJUSTMENT FILING OF AVISTA ) APPLICATION OF AVISTA
CORPORATION ) CORPORATION
I. INTRODUCTION
I In accordance with Idaho Code §61-502 and Idaho Public Utilities Commission
2 ("Commission") Rule of Procedure ("RP") 052, Avista Corporation, doing business as
3 Avista Utilities (hereinafter "Avista" or "Company"), at 1411 East Mission Avenue,
4 Spokane, Washington, respectfully files its Power Cost Adjustment (PCA) annual rate
5 adjustment filing in the above referenced case. The Company requests the Commission
6 issue an order approving the level of power costs deferred in the surcharge direction for
7 the period July 1, 2025 through June 30, 2026, and approving a PCA surcharge rate of
8 0.1570 per kilowatt-hour to be effective October 1, 2026. The Company requests that this
9 filing be processed under the Commission's Modified Procedure Rules through the use
10 of written comments.
I I Avista is a utility that provides service to approximately 423,000 retail electric
12 customers and 383,000 natural gas customers in a 30,000 square-mile service territory
13 covering portions of northern Idaho, eastern Washington, and Oregon. The largest
AVISTA'S PCA ANNUAL RATE ADJUSTMENT FILING PAGE 1

I community served by Avista is Spokane, Washington, which is the location of its
2 corporate headquarters. The Company requests that all correspondence related to this
3 Application be directed to:
4 Anni Glogovac Annette Brandon
5 Counsel for Regulatory Affairs Strategic Initiatives Manager
6 Avista Corporation Avista Corporation
7 P.O. Box 3727 P.O. Box 3727
8 1411 E. Mission Avenue, MSC 27 1411 E. Mission Avenue, MSC 27
9 Spokane, Washington 99220-3727 Spokane, Washington 99220-3727
10 Telephone: [phone] Telephone: [phone]
11 E-mail: anni._lg_o o_ v�ackavistacorp.com E-mail:
12 annette.brandon(&,avistacorp.com
13
14 Avista Dockets (Electronic Only) -AvistaDockets(d),avistacorp.com
15
16 II. BACKGROUND
17 Avista's PCA is used to track changes in revenues and costs associated with
18 variations in hydroelectric generation, secondary prices, thermal fuel costs, and changes
19 in power contract revenues and expenses. Avista's existing PCA methodology and
20 method of recovery were approved in Case No.AVU-E-07-01 by Order No. 30361,dated
21 June 29,2007. In that case,the Commission approved a change in the PCA methodology
22 from a "trigger and cap" mechanism to a single annual PCA rate adjustment filing
23 requirement.
24 The Commission also approved a change in the method of the PCA deferral rate
25 adjustment from a uniform percentage basis, to a uniform cents per kilowatt-hour basis,
26 effective with the October 1, 2007 PCA rate change. By Order No. 32206 in Case No.
27 GNR-E-10-03, dated March 15, 2011,the Commission modified the retail revenue credit
28 methodology and approved a Load Change Adjustment Rate(LCAR)based on the energy
AVISTA'S PCA ANNUAL RATE ADJUSTMENT FILING PAGE 2

I classified portion of embedded production revenue requirement, effective April 1, 2011.
2 The Commission approved the following procedural schedule for administering the
3 annual PCA filings:
4 August 1: Company filing for prior July—June deferral period
5 September 1: Review and comments by Staff and other interested parties
6 October 1: Commission Order/effective date of PCA rate adjustment
7
8 The present PCA rebate was made effective on October 1,2025. On July 31,2025,
9 Avista filed its annual PCA rate adjustment for the period July 1, 2025, through June 30,
10 2026, and requested a PCA rebate rate of 0.3010 per kilowatt-hour effective October 1,
11 2025. The Commission approved that request in Case No. AVU-E-25-07, by Order No.
12 36777, dated September 29, 2025.
13 The proposed PCA rate adjustment of 0.157¢ per kilowatt-hour would surcharge
14 to customers approximately $14.6 million, or 4.2%, effective October 1, 2026. The
15 surcharge is primarily related to the expiration of the existing rebate rate and actual power
16 supply costs that were higher than the level of costs embedded in customer rates. These
17 higher costs were primarily related to a downward shift in market energy pricing which
18 had impacts throughout the portfolio but most directly to"Net Power Purchases Expense"
19 2) wind generation resources excluded from the authorized base for the September 2025
20 through August 2026 period and, 3) higher customer loads during several months of the
21 year.
22
23 III.DEFERRALS—JULY 1, 2025 THROUGH JUNE 30, 2026
24 The amount of power cost deferrals for the period July 1, 2025, through June 30,
AVISTA'S PCA ANNUAL RATE ADJUSTMENT FILING PAGE 3

1 2026, is shown in Table No. 1 below, as well as interest for the same period. Company
2 witness Mr. Holland's testimony provides an explanation of the factors causing the
3 deferral entries for the period. Company witness Ms. Brandon's testimony addresses the
4 deferral, Renewable Energy Credit Benefit, and interest amount.
5 Table No. 1 — Summary of Deferral Balance
6 Power Supply Deferrals(July 2025 - June 2026) $ 8,032,648
Energy Imbalance Market Operations and Maintenance Expense $ 194,495
7 Renewable Energy Credit Retirement Benefit $ (2,717,969)
Interest $ 56,428
8 Total Deferral Balance $ 5,565,602
9 Quarterly reports have been filed with the Commission regarding actual PCA
10 deferral entries to date.' An additional copy of those reports for the quarters of Q3 2025,
11 Q4 2025, Q1 2026 and Q2 2026 have been included with this filing and have also been
12 provided to Clearwater Paper Corporation and Idaho Forest Group.
13
14 IV. PROPOSED RATE TO BE EFFECTIVE OCTOBER 1, 2026
15 The Company is proposing a uniform cents per kilowatt-hour PCA surcharge rate
16 of 0.1570 to be effective October 1, 2026 (from the present rebate rate of 0.3010 per
17 kilowatt-hour). See page 1 of Ms. Brandon's Exhibit No. AMB-1 for the calculation of
18 the proposed rate. Attached to this Application as Exhibit "A" is a copy of the proposed
19 tariff, Schedule 66, which contains the proposed PCA rate. Exhibit"A"also includes the
20 proposed changes to Schedule 66 in strike out/underline format. The proposed rate is
1 In Case No. AVU-E-23-08,Order No. 35937,the Company was directed to submit PCA reports,which
must include the Power Transaction Register (PTR) and Gas Accounting Data Download (GADD) in
Staff s recommended file formats, to the Commission on a quarterly basis. The Company filed its first
quarterly report on October 13,2023,beginning with 31 Quarter of 2023,which included the confidential
PTR and GADD reports for that quarter. Subsequent quarterly filings of the alike have been made to date.
AVISTA'S PCA ANNUAL RATE ADJUSTMENT FILING PAGE 4

I designed to rebate the following:
2 Table No. 2—Amortization Balance Calculation!
Power Supply Deferrals &EIM(July 2025 - June 2026) $ 8,227,143
3 Renewable Energy Credit Retirement Benefit $ (2,717,969)
Interest $ 56,428
4 Total Deferral Balance $ 5,565,602
5
Unamortized Balance from Previous Deferrals(prior to July 1, 2025) $ (11,302,437)
6 Amortization July 2025 - June 2026 $ 8,705,513
Interest $ (354,457)
7 Total Remaining Amortization Balance $ (2,951,381)
8 PCA Year Ending June 30,2026 $ 2,614,221
9
Projected Amortization and Total Interest(July 2026-September 2026) $ 2,365,097
10
11 TOTAL BALANCE FOR AMORTIZATION $ 4,979,318
12 After applying the conversion factor related to commission fees and uncollectible
13 customer accounts to the "Total Balance for Amortization" shown above, the resulting
14 credit balance of $5,001,017 is divided by forecasted kilowatt-hours to derive the
15 proposed rebate rate of 0.1570 per kilowatt-hour.3
16 Since PCA rate changes are spread on a uniform cents per kilowatt-hour basis,the
17 resulting percentage decreases vary by rate schedule. Page 1 of Ms. Brandon's Exhibit
18 No. AMB-1 shows the effect of the proposed PCA rebate by rate schedule. The overall
19 increase in revenue, after accounting for the expiration of the existing rebate, and the new
20 rebate, is approximately $14.6 million or 4.2%. The revenue impact by rate schedule is
21 as follows:
2 Power Supply Deferrals like item is combination of Power Supply Deferrals of $8,032,648 + EIM
Operations and Maintenance of$194,495 as shown in Table No. 1 for a total of$8,227,143
3 Total Balance for Amortization$4,979,318 divided by conversion factor 0.995661 =$5,001,017.
AVISTA'S PCA ANNUAL RATE ADJUSTMENT FILING PAGE 5

1
Schedule Percent change
2 Type of Service Number on Billed Revenue
Residential 1 3.6%
3 General Service 11,12 4.3%
Large General Service 21,22 3.9%
4 Extra Large General Service 25 6.6%
Clearwater 25P 7.9%
Pumping Service 31,32 3.5%
5 Street&Area Lights 41-49 1.0%
Total 4.2%
6
7 Residential customers using an average of 939 kilowatt-hours per month would see their
8 monthly bills decrease from$119.52 to $123.83, a decrease of$4.31 per month, or 3.6%.
9 This bill impact does not consider the effects of other filings Avista has made that will go
10 into effect on October 1, 2026.
11
12 V. REQUEST FOR RELIEF
13 The Company requests that the Commission issue an order approving power costs
14 deferred for the period July 1, 2025 through June 30, 2026, and approving a PCA
15 surcharge rate of 0.1570 per kilowatt-hour to be effective October 1, 2026. Under the
16 Company's proposal, the PCA rate for all customers, including residential customers,
17 would increase from a rebate rate of 0.3010 per kilowatt-hour to a surcharge rate of
18 0.1570 per kilowatt-hour. The Company requests that the matter be processed under the
19 Commission's Modified Procedure rules through the use of written comments.
20 Dated at Spokane, Washington this 31St day of July 2026.
21 AVISTA CORPORATION
22 By: ( �w 42gyLA2
23 Coun el for Regulatory Affairs
24 ISB #13010
AVISTA'S PCA ANNUAL RATE ADJUSTMENT FILING PAGE 6

CASE NO. AVU-E-26-05
2026 Idaho PCA Filing
Exhibit "A"

Twenty-Eighth Revision Sheet 66
Canceling
I.P.U.C. No.28 Twenty-Seventh Revision Sheet 66
AVISTA CORPORATION
d/b/a Avista Utilities
SCHEDULE 66
TEMPORARY POWER COST ADJUSTMENT - IDAHO
APPLICABLE:
To Customers in the State of Idaho where the Company has electric service
available. This Power Cost Adjustment shall be applicable to all retail customers for
charges for electric energy sold. This Rate Adjustment is designed to recover or
rebate a portion of the difference between actual and allowed net power supply costs.
MONTHLY RATE:
The energy charges of electric Schedules 1, 11, 12, 21, 22, 25, 25P, 31, 32, and
42-49 are to be increased by 0.1570 per kilowatt-hour in all blocks of these rate
schedules.
SPECIAL TERMS AND CONDITIONS:
The rates set forth under this Schedule are subject to periodic review and
adjustment by the IPUC based on the actual balance of deferred power costs.
Service under this schedule is subject to the Rules and Regulations contained
in this tariff.
The above Rate is subject to increases as set forth in Tax Adjustment
Schedule 58.
Issued July 31, 2026 Effective October 1, 2026
Issued by Avista Utilities
B(y� Patrick Ehrbar— Director of Regulatory Affairs

Twenty-Seventh Revision Sheet 66
Canceling
I.P.U.C. No.28 Twenty-Sixth Revision Sheet 66
AVISTA CORPORATION
d/b/a Avista Utilities
SCHEDULE 66
TEMPORARY POWER COST ADJUSTMENT - IDAHO
APPLICABLE:
To Customers in the State of Idaho where the Company has electric service
available. This Power Cost Adjustment shall be applicable to all retail customers for
charges for electric energy sold. This Rate Adjustment is designed to recover or
rebate a portion of the difference between actual and allowed net power supply costs.
MONTHLY RATE:
The energy charges of electric Schedules 1, 11, 12, 21, 22, 25, 25P, 31, 32, and
44-49 are to be decreased by 0.3010 per kilowatt-hour in all blocks of these rate
schedules.
SPECIAL TERMS AND CONDITIONS:
The rates set forth under this Schedule are subject to periodic review and
adjustment by the IPUC based on the actual balance of deferred power costs.
Service under this schedule is subject to the Rules and Regulations contained
in this tariff.
The above Rate is subject to increases as set forth in Tax Adjustment
Schedule 58.
Issued July 31, 2025 Effective October 1, 2025
Issued by Avista Utilities
B(y� Patrick Ehrbar— Director of Regulatory Affairs

Twenty-Eighth Revision Sheet 66
Canceling
I.P.U.C. No.28 Twenty-Seventh Revision Sheet 66
AVISTA CORPORATION
d/b/a Avista Utilities
SCHEDULE 66
TEMPORARY POWER COST ADJUSTMENT - IDAHO
APPLICABLE:
To Customers in the State of Idaho where the Company has electric service
available. This Power Cost Adjustment shall be applicable to all retail customers for
charges for electric energy sold. This Rate Adjustment is designed to recover or
rebate a portion of the difference between actual and allowed net power supply costs.
MONTHLY RATE:
The energy charges of electric Schedules 1, 11, 12, 21, 22, 25, 25P, 31, 32, and
42-49 are to be increased by 0.1570 per kilowatt-hour in all blocks of these rate
schedules.
SPECIAL TERMS AND CONDITIONS:
The rates set forth under this Schedule are subject to periodic review and
adjustment by the IPUC based on the actual balance of deferred power costs.
Service under this schedule is subject to the Rules and Regulations contained
in this tariff.
The above Rate is subject to increases as set forth in Tax Adjustment
Schedule 58.
Issued July 31, 2026 Effective October 1, 2026
Issued by Avista Utilities
B(y� Patrick Ehrbar— Director of Regulatory Affairs