20250129Application.pdf

' 11
RECEIVED
Avista Corp. 2025 January 29
1411 East Mission P.O. Box 3727 IDAHO PUBLIC
Spokane, Washington 99220-0500 UTILITIES COMMISSION
Telephone [phone] Cbse1% AVUE-25-02
Toll Free 800-727-9170
January 29, 2025
Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd. Bldg. 8, Ste. 201-A
Boise, Idaho 83714
RE: Case No. AVU-E-25- Avista's Capacity Deficiency Application
Dear Secretary:
Avista Corporation, dba Avista Utilities, hereby submits to the Commission its filing to establish
its Capacity Deficiency Period to be used for avoided cost calculations in compliance with Order
No. 35810. Please note that Attachment A is CONFIDENTIAL in its entirety.
Please direct any questions regarding this filing to John Lyons at 509-495-8515.
Sincerely,
lQvsva" F"#dd
Shawn Bonfield
Sr. Manager of Regulatory Policy& Strategy
Avista Utilities
509-495-2782
Shawn.bonfield(a),,avistacorp.com

Case 1%AV E-25-02
David Meyer
VP & Senior Counsel for Regulatory
And Governmental Affairs
Avista Corporation
1411 East Mission, MSC-10
Spokane, WA 99202
Phone: [phone]
Facsimile: [phone]
Email: [e-mail]
Attorney for Avista Corporation
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF AVISTA CORPORATION'S) CASE NO. AVU-E-25-
COMPLIANCE FILING TO UPDATE )
AND ESTABLISH ITS CAPACITY DEFICIENCY )
PERIOD TO BE USED FOR AVOIDED COST )
CALCULATIONS )
AVISTA CORPORATION'S
COMPLIANCE FILING

I. INTRODUCTION
Avista Corporation, doing business as Avista Utilities (hereinafter Avista or the
Company), at 1411 East Mission Avenue, Spokane, Washington, respectfully submits to
the Idaho Public Utilities Commission(Commission)this filing, in compliance with Order
Nos. 32697 and 32802 in Case No. GNR-E-11-03, and 35810 in Case No. GNR-E-23-01,
seeking approval from the Commission of the capacity deficiency period to be utilized for
the Company's avoided cost calculations.
Communications in reference to this filing should be addressed to:
David Meyer Shawn Bonfield
VP & Senior Counsel for Regulatory Sr. Manager, Regulatory Policy
& Governmental Affairs Avista Corporation
Avista Corporation P.O. Box 3727
P.O. Box 3727 1411 E. Missions Avenue, MSC-27
1411 E. Mission Avenue, MSC-10 Spokane, WA 99220-3727
Spokane, WA 99220 Phone [phone]
Phone: [phone] Shawn.Bonfield(&avistacorp.com
David.Meergavistacorp.com
II. BACKGROUND
In Order No. 33917 in Case No. PAC-E-17-09, the Commission amended Order
No. 32697 such that utilities were to file "their first capacity deficiency cases after the
Commission has acknowledged their IRP reports." Order No. 35810 modified the filing
date to "within thirty (30) days of filing its respective IRP." Avista filed its 2025 Electric
Integrated Resource Plan (IRP) with the Commission on December 30, 2024, thus hereby
seeks approval from the Commission of the capacity deficiency period to be utilized for
the Company's avoided cost calculations.
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III. CAPACITY DEFICIENCY PERIOD
Avista's 2025 Electric IRP identifies the first long-term load deficit on January 1,
2030. This is earlier than the capacity deficiency date identified in the 2023 Electric IRP
because of major changes to the generation side of Avista's load & resource position,
identified on page 137 of the 2025 Electric IRP regarding resources:
• A 30-year Power Purchase Agreement(PPA) (97.5 MW)with Clearwater Wind
online in September 2024.
• Stimson Lumber co-gen (5.8 MW), a Qualifying Facility(QF) located in
Plummer, Idaho closed in 2024.
• A new Washington industrial customer increases load by 34.3 aMW beginning in
August 2024.
• Three Columbia Basin Hydro projects begin in 2025 totaling 105.8 MW of
capacity.
• A 5% slice (87.5 MW) of the Chelan PUD PPA comes online in 2026.
There are also several Avista-owned thermal plants expected to leave the resource
portfolio over the next 20 years. These resources are shown in Table 1 and discussed on
page 57 of the 2025 Electric IRP.
Table 1: Thermal Resource Portfolio Exit Assumptions
Resouwr��V Fuel Type ?Final Capacity(MW
in January)
Colstrip Units 3 &4 Coal 2025 222.0
Northeast Natural Gas 2029 64.0
Boulder Park Natural Gas 2039 24.6
Kettle Falls CT Natural Gas 2039 10.9
Lancaster Natural Gas 2041 281.7
Rathdrum CTs Natural Gas 2044 174.5
Total 777.7
On the load side,the near-term peak load forecast increased resulting from the new
record peak load experienced in January 2024 (see page 111 of the 2025 Electric IRP).
Figures 1 and 2 below show the net peak position for both the winter and summer
peak hour positions (from Figures 5.2 and 5.3 on page 142 of the 2025 Electric IRP).
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Monthly details of the load & resource position are provided in Confidential Attachment
A and includes the PRISM file from the 2025 Electric IRP. PRISM uses the monthly peak
loads based on 50th percentile coldest or hottest day weather. Table 2 includes the detailed
monthly position used within the 2025 IRP(found within the attached PRISM model within
the tab "Position Summary"). As noted in the 2025 Electric IRP on page 141, "Based on
Avista's analysis of resource adequacy, Avista is temporarily short capacity in 2026 until
a sale contract expires. After this contract expires, Avista is in a near balanced position
until 2030. In 2030, between load growth, retirement of the Northeast CT, and expiration
of a long-term PPA the utility will be deficient on a permanent basis until new resources
are acquired." As such, Avista proposes using the 2030 resource position rather than the
earlier short position for the capacity deficiency period because the 2026 deficit will be
addressed by market purchases during the power procurement hedging strategy and other
short positions are de minimis and will also be addressed with the same strategy.
Figure 1: Winter One-Hour Capacity Load & Resources
3,000
2,500
N2,000
c:1,500
a�
21,000
Existing/Committed Resources
500 Planning Requirement w/ PRM
Load Forecast(1 in 2 Event)
0
CO f1- 00 OD O - N M t u7 (D f-- 00 07 O N M u7
N N N N M M M M M M M M M M � ItIt �
O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N
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Figure 2: Summer One-Hour Capacity Load & Resources
3,000
2,500
N2,000
3:1 ,500
a�
aD
21,000
7
Existing/Committed Resources
500 Planning Requirement w/ PRM
Load Forecast (1 in 2 Event)
o ■ A ■ ■
(0 rl- 00 O O V­ N M ;I- M (fl ti 00 O O N M �T U)
N N N N co M M M M M co co co M It It It It � �
O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N
Table 2: Monthly Capacity Position (MW)
Year Jan Feb Mar Apr May Jun Jul AugSep Oct Nov Dec
2026 40 108 288 369 243 136 9 22 271 247 153 4
2027 3 146 333 429 306 198 65 33 327 296 194 44
2028 2 140 324 424 305 192 47 27 315 292 189 37
2029 2 157 333 428 309 191 63 44 337 301 197 53
2030 55 90 267 358 266 130 3 33 264 246 131 15
2031 62 86 268 360 265 122 11 39 276 245 132 14
2032 71 77 254 350 264 99 17 50 256 234 118 28
2033 107 41 219 318 232 111 25 58 257 204 80 69
2034 230 76 105 210 136 14 117 150 159 99 25 183
2035 225) (76) 102 209 130 33 (128) (155) 152 98 (24) (183)
2036 (236) (83) 99 201 126 10 (132) (162) 138 90 (35) (191)
2037 297 139 46 154 84 24 175 207 120 45 85 246
2038 365 201 13 102 36 87 234 258 68 10 151 316
2039 (398) (231) (43) 78 7 (116) (277) (303) 45 (39) (178) (348)
2040 (473) (303) (107) 19 (41) (189) (343) (375) (17) (96) (245) (417)
2041 525 351 157 27) 72 197 381 415 64 138 290 474
2042 838 666 471 263 276 471 657 695 326 426 604 789
2043 910 736 538 324 326 494 684 721 367 481 665 858
2044 992 814 (612)1 (388) 383 (553) (741) 787 408) (548) (741) 935
2045 1,291 1,115 904 674 574 792 996 1,032 652 813 1,033 1,246
IV. CAPACITY POSITION DETERMINATION METHODOLOGY
The long-term capacity shortage identified for 2030 was developed by comparing
peak load plus a planning reserve margin (PRM) to the total expected capacity of its
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resources (adjusted for expected maintenance).' This method is intended to ensure Avista
is prepared to meet extreme load conditions in 95% of future extreme conditions. Avista
uses this reliability metric because meeting extreme load requires the Company to be able
to meet peak events lasting longer than the highest one-hour peak. Avista's PRM is
determined by conducting an hourly study for a complete year (e.g. 2030) simulating
existing resources,assuming 330 MW2 market limitation,and an expected load using 1,000
different futures varying weather conditions and forced outages. The goal of this analysis
is to determine how much additional capacity is required to ensure the system can meet all
load hours in 950 of the 1,000 simulations. This reliability metric is known as meeting a
5%Loss of Load Probability (LOLP) standard.
After Avista conducts this study, it then estimates the PRM based on the results of
the study. For Avista,the PRM in the winter is 24%. The PRM is determined by summing
the Qualifying Capacity Contribution (QCC)4 of all existing and "required" resources to
determine the 5%LOLP result and then dividing by the expected 1-in-2 peak load. Avista
did not develop the initial QCCs for each of its resources. Rather than developing QCC
values,Avista uses the Western Resource Adequacy Program(WRAP)values. The WRAP
provides a QCC for each participating utility's resource's ability to meet regional resource
adequacy requirements where Avista is included within. Using WRAP values creates a
consistency of resource assumptions in other resource adequacy settings and is more
efficient than the utility spending significant staff time to develop these values on their
'All data pertaining to loads and resources are included within Avista's PRiSM Model.
2 This 330 MW market limit is only enforced when market conditions are expected to be tight(i.e.,extreme
weather conditions).
s Avista's summer planning margin is 16%.It is determined by the single largest contingency resource
(Coyote Springs 2)compared to expected load.
a QCC is also known as Effective Load Carrying Capability(ELCC).
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own. However, the WRAP uses a different load metric, and it has a very short-term focus.
Avista is planning for the next 20 years and therefore must adjust long-term QCCs and not
use the WRAP's PRM for long-term resource planning. Since the WRAP does not provide
long-term QCCs incorporating the expected decline in QCC values for variable energy
resources (VERB) and energy storage. Avista estimates long-term QCC values by
combining values from studies conducted by the WRAP and an E3 study completed in
2019 (2025 Electric IRP, page 205). Avista is currently co-sponsoring an E3 update to the
2019 study.
To ensure the QCC values estimated into the future are valid and the system is
expected to be reliable,Avista conducts a reliability study with the resources chosen within
the Preferred Resource Strategy (PRS) for both 2030 and 2045. The results of this study
show with the PRS resources the system is below the 5% LOLP threshold (2025 Electric
IRP, page 66).
The methodology described above represents how Avista determines capacity need
using Staff s recommendations to ensure Avista's reliability metric uses Avista's resource
adequacy study results rather than regional requirements. If Avista used the prior
methodology approved in past orders for resource capacity contribution, the resulting
capacity need would be the same. This is due to the fact the PRM is the arithmetic result
of the resource shortfall of the available resources against load. This is because both
methods would be based upon the resource adequacy study to calculate its resource deficit.
The only difference is the methodology proposed here is the accounting of the quantity of
resource capacity of existing resources. Consider the following example shown in Table 3
(values are used for illustrative purposes only). In this example, the scenarios have the
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same peak load, and the net resource positions are both short 50 MW (based upon the
resource adequacy study). The difference between the two studies is the methodology of
resource capacity accounting and the PRM, but the PRM is an algebraic result of the
amount of additional capacity to plan for and ensure the 50 MW shortfall is covered.
Table 3: Illustrative L&R Methodology(MW)
Item Method 1 Method 2
Peak Load 1,000 1,000
PRM 280 240
Resource Adequacy Load 1,280 1,240
Total Available Resource 1,230 1,190
Resource Position -50 -50
V. MODIFIED PROCEDURE
Avista believes that a hearing is not necessary to consider the issues presented
herein and respectfully requests that this Application be processed under Modified
Procedure, i.e., by written submissions rather than by hearing. RP 201 et seq. If the
Commission determines that a technical hearing is necessary, the Company will be ready
to prepare and present its testimony in such hearing.
V. REQUEST
The Company respectfully requests that the Commission issue an order to approve
of its capacity deficiency period, with a first deficit occurring on January 1, 2030.
DATED at Spokane, Washington, this 29th day of January 2025.
AVISTA CORPORATION
By/s/David Meyer
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David J. Meyer
Vice President and Chief Counsel for
Regulatory and Government Affairs for
Avista Corp.
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