20250731Reply Comments.pdf

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RECEIVED
Avista Corp. uly 31, 2025
p' IDAHO PUBLIC
1411 East Mission P.O. Box 3727 UTILITIES COMMISSION
Spokane, Washington 99220-0500
Telephone [phone]
Toll Free 800-727-9170
July 31, 2025
Commission Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd. Bldg. 8, Ste. 201-A
Boise, Idaho 83714
RE: Case No. AVU-E-24-13 - Avista's Reply Comments - 2025 Electric Integrated Resource
Plan
Dear Secretary:
Avista Corporation, dba Avista Utilities (Avista or the Company), submits the following
comments in response to comments received from the Idaho Public Utilities Commission Staff
(Staff)and the Northwest Energy Coalition(NWEC)in the matter of the Company's 2025 Electric
Integrated Resource Plan (IRP) in Case No. AVU-E-24-13. Avista appreciates the time and
diligence of Idaho Staff and NWEC, and the valuable inputs given during the Technical Advisory
Committee (TAC) process and looks forward to continued collaboration for planning in future
IRPs.
The following comments are in response to Staff s recommendations.
Replies to Staff comments concerning Avista's 2025 Electric IRP:
Recommendation
The Company continue to evaluate potential resource allocation methods due to the divergence in
resource strategies and to keep the Commission informed about any potential changes in the
resource allocation method.
Response
At this time, Avista is not proposing any changes to resource allocation between Idaho and
Washington beyond the currently used Production Transmission (PT) ratio. Although state level
resource allocation would solve certain issues the Company may face in the future as state resource
policies differ, it is Avista's understanding that any change in resource cost allocation must be
approved in a general rate case, after an agreement between both Idaho and Washington on how

resource costs and associated energy would be allocated prior to being presented in the general
rate case.
Two Washington State policies create the need for a potential change in cost allocation: 1)Climate
Commitment Act(CCA), and 2) Clean Energy Transformation Act(CETA). These policies either
require the Company to potentially change the dispatch of existing resources or acquire clean or
non-greenhouse gas emitting resources at a higher cost than the least cost alternatives. These two
policies have created some tension concerning cost recovery,but not to the level of the immediate
need to develop an alternative process to divide resources, but such a process may be required in
the future if resource choices or dispatch decisions are required to be specific to each jurisdiction.
Recommendation
The Company during the Request for Proposal (RFP) process evaluate the cost impact to Idaho
and the fair allocation of generation and transmission resources for Idaho caused by any
Washington specific resources.
Response
Avista plans to evaluate resources bid into the 2025 All-Source RFP using a methodology from
both the perspectives of each jurisdiction.Avista will select the lowest cost project,but if resources
are selected that are biased towards use mainly for Washington, this may necessitate a different
resource cost allocation methodology than the current PT ratio methodology.
Recommendation
The Company address the aforementioned CCA issues in the next IRP.
Response
Avista will not include direct CCA costs in the 2027 IRP for Idaho's cost forecast, even though
these costs presently exist for the utility on behalf of Idaho customers. Further, the Company will
use an electric price forecast for resource alternatives not directly including the CCA pricing,
specifically a price forecast for northwest energy without delivery into Washington State will be
used for avoided cost purposes.
Recommendation
The Company include a scenario where the Washington market and the California market are not
linked in the next IRP.
Response
Avista anticipates wholesale electric market prices will be higher during some periods of the year
if the California/Quebec and Washington greenhouse gas credit markets do not link due to the
potential for acquiring allowances for two state programs when transacting between regions. At
the time of the 2025 IRP, the State of Washington passed legislation to enable linkage between
programs. At this time, linkage has not occurred,but Washington is actively pursuing linkage with
California.Avista agrees to model this scenario if the market is not linked or not making significant
progress on linkage during the IRP process for linkage for the 2028 forecast year(this will be the
first year considered in the 2027 IRP.
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Recommendation
The Company improve the clarity of market prices without the CCA in the next IRP.
Response
Avista agrees to provide a presentation at a 2027 TAC meeting on how the wholesale electric price
forecast is developed and how the CCA is accounted for in the forecast. Further, Avista will
provide a price forecast for the Idaho jurisdiction without direct CCA pricing in the 2027 IRP.
Recommendation
The Company continue to improve the IRP reliability analysis to measure resource adequacy
metrics on additional portfolios under evaluation across more years in the planning horizon.
Response
Avista reliability analysis in the 2025 IRP was conducted for 2030 and 2045 for a limited number
of scenarios. The scenarios with reliability modeled were considered based on whether there is a
reliability concern and not for scenarios with objectives focusing on other issues. While it would
be informative to have reliability analysis completed on every scenario, it may not be as useful in
some scenarios because of the intent of what is being considered under those scenarios. Avista
does plan to conduct more reliability analysis, however, the extent of the additional analysis will
be limited based upon available tools. Avista's current tool resides within an Excel spreadsheet
with an optimization routine. Avista is exploring the use of the Aurora model to make it feasible
to model additional years and scenarios possible in a reasonable amount of time.
Recommendation
The Company exercise caution when planning DSM programs for EE measures and be ready to
provide detailed support for the costs and cost-effectiveness of related programs.
Response
Avista is making significant changes in the 2027 IRP for the analysis of energy efficiency. Avista
will be working with Cadmus for the 2027 and 2029 IRPs to provide third party analysis of
potential energy efficiency and demand response measures.
Recommendation
The Company to continue to review the results of the CPA for additional errors and to carefully
review the results of third-party evaluation and studies in the future.
Response
Avista agrees that careful evaluation of third-party studies in future IRPs will help to ensure
results are reasonable and achievable.
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The following comments are in response to NWEC.
Load Forecasting
The Idaho PUC and Avista should create a new rate class for data centers, cryptocurrency
operations and other similar large loads, and the Commission should develop additional rules it
deems necessary.
Avista should require data centers, cryptocurrency operations and similar large loads to sign
minimum 10-year contracts to ensure that infrastructure investments to serve data centers are fully
recovered.
Avista should require data centers to agree to pay for a minimum amount of energy monthly or
annually, even if the facility uses less than expected, as well as requiring the facility to pay an
additional fee if they use excess energy.
Avista should require new data centers to pay the full cost of any transmission upgrades required
to serve them.
Response
Avista is in the process of developing policies regarding large loads, such as data centers or
cryptocurrency miners. The Company is not planning on developing a rate class for these types of
customers currently but is monitoring and analyzing if there is a need to separate these types of
customers as they are added to regional loads. NWEC's other suggestions concerning these types
of large loads are in line with the internal discussions about policies being developed.
Energy Efficiency
We encourage Avista to take a closer look at how the context for utility operations, resource costs
and critical peak challenges is dramatically increasing the real cost-effectiveness of energy
efficiency, including a revamped assessment of diurnal, seasonal and critical peak conditions.
Response
The energy efficiency analysis for the 2025 IRP's Conservation Potential Assessment (CPA) will
be done by a new consultant,Cadmus,for the 2027 and 2029 IRPs.This new work plus the updated
load forecasting work may result in different amounts and types of energy efficiency being cost
effective.
Demand Response
No doubt the effort to achieve substantial accelerated DR [demand response] is considerable and
will take several years,but the results of the draft IRP pose a serious threat of"analysis paralysis."
There are increasing opportunities for achieving greater demand response.
Response
The DR potential study will be done by a new consultant, Cadmus, for the 2027 and 2029 IRPs.
The results of the 2025 All-Source RFP, which included DR bids, will determine actionable
projects if cost competitive against other alternatives.
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Storage
We think storage can be counted on for a greater amount of new system resources starting immediately.
Response
Avista is currently evaluating bids from the 2025 All-Source RFP. If storage is a cost-effective
solution to solve capacity deficits, it will be determined through the RFP process.
New Supply Resources
While investigating further extension to wholesale gas supply would provide useful information,
we strongly recommend adding a comprehensive assessment of these non-gas alternatives.
Response
Avista looks forward to discussing how these assessments might apply in the 2027 IRP in the
upcoming TAC meetings.
Western Day-ahead Market Opportunities
In its next IRP,we encourage Avista to include an analysis of the benefits of accessing a day-ahead
market including the ability access a large set of diverse resources and an objective assessment of
independent governance ultimately controlled by western stakeholders.
Response
The Company is still in the process of determining which regional market to participate in, this
analysis and decision will be conducted outside of an IRP process.
Transmission
While the draft IRP indicates a related interest in upgrading the Colstrip Transmission System
("CTS"), we also encourage Avista to consider the possibilities for transmission expansion
between the CTS and the Avista system. While that is necessarily a long and complex build and
would involve multiple partners, we believe there is major value in strengthening access to
Montana wind as well as the MISO and Southwest Power Pool markets that could be enabled by
North Plains. ... Avista may also benefit from a focused reconductoring analysis.
Response
Avista agrees strengthening the Montana transmission system will be advantageous for Avista's
customers.
Resource Adequacy
NWEC participates in the public process of the Western Resource Adequacy Program("WRAP")
and applauds Avista's program participation. We encourage a more nuanced approach to its
inclusion within the IRP context.
Response
Avista plans to continue using WRAP information for resource planning where appropriate.
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Climate Baseline
We are supportive of Avista's forward-looking approach to a climate-adjusted baseline. However,
we also encourage Avista to adopt a consistent approach to use of IPCC metrics and methods. For
example,in our view RCP 4.5 ("representative concentration pathway")should be employed year-
round.
Response
Avista will be revisiting the base climate assumptions used in the development of the IRP forecasts
and appreciate the input regarding moving to the use of a single RCP instead of using different
RCPs for the winter and summer periods. Avista appreciates NWEC sharing their position.
If you have any questions regarding this filing,please contact James Gall at 509-495-2189 or John
Lyons at 509-495-8515.
Sincerely,
lals" Smj�"
Shawn Bonfield
Sr. Manager of Regulatory Strategy &Policy
509-495-2782
Shawn.bonfield&avistacorp.com
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