20241112AVU to Staff 7-8.pdf

RECEIVED
Tuesday, November 12, 2024
IDAHO PUBLIC
UTILITIES COMMISSION
AVISTA CORPORATION
RESPONSE TO REQUEST FOR INFORMATION
JURISDICTION: IDAHO DATE PREPARED: 11/12/2024
CASE NO: AVU-E-24-10 WITNESS: N/A
REQUESTER: Staff RESPONDER: James Gall
TYPE: Production Request DEPARTMENT: Energy Resources
REQUEST NO.: Staff-007 TELEPHONE: [phone]
REQUEST:
Please respond to the following regarding the proposed load forecast for the period from 2025
through 2028:
a. Please explain why the proposed load forecast in this case is consistently higher than the
approved load forecast in Case No. AVU-E-23-13 for the period from 2025 through 2028.
b. Specifically, what causes the initial difference between the two load forecasts in 2025?
c. Compared to the load forecast in Case No. AVU-E-23-13, if the load increase in this case
is due to customer additions,please provide a breakdown of customers by class and by year
of customer additions from 2025 through 2028.
RESPONSE:
a. The load forecast filed in Case No. AVU-E-23-13 utilized forecasting methods that Avista
has used for many years. Avista determined that it would collaborate with a consultant to
develop an end use load forecast for the 2025 Integrated Resource Plan (IRP). On
December 20, 2023, Avista filed an updated load forecast in Case No. AVU-E-23-13,
which was the result of the end use forecasting methodology. Throughout the period
between December 2023 and July 2024, there were many iterations of the load forecast to
address issues such as identifying if the data was calendar or billed data, which weather
forecast should be used, and the discovery that load shapes from different geographic
regions then Avista's service territory had been used in the end use forecast. In addition, a
large industrial load was added between the two load forecasts. The load forecast filed in
AVU-E-24-10 incorporated the resolution of the above issues.
b. The end use forecast performed by the consultant for the 2025 IRP and used in the AVU-
E-24-10 filing, did not include 2025 since it was for the 2026-2045 period.
c. Customer additions were similar for each load forecast except for one large industrial
customer.

AVISTA CORPORATION
RESPONSE TO REQUEST FOR INFORMATION
JURISDICTION: IDAHO DATE PREPARED: 11/12/2024
CASE NO: AVU-E-24-10 WITNESS: N/A
REQUESTER: Staff RESPONDER: James Gall
TYPE: Production Request DEPARTMENT: Energy Resources
REQUEST NO.: Staff-008 TELEPHONE: [phone]
REQUEST:
Response to Staff Production Request No. 6 states that the nameplate of Clearwater is 60 MW
within the context of the amount available to Avista as part of its PURPA agreement, even though
the overall nameplate of the generation facility is 132.2 MW. Please respond to the following:
a. Does the PURPA Agreement state the nameplate available to Avista is 60 MW? If so,
please provide the page number of the PURPA agreement that specifies the 60 MW.
b. If not, please explain how the 60 MW is determined.
RESPONSE:
a. No, the PURPA Agreement does not state the 60 MW value.
b. Power generation varies hour to hour from the facility, for example between November 1,
2019 and October 31, 2024, the average generation purchased by Avista was 48.2 aMW,
but the 5th percentile is 22 MW and 95th percentile 59 MW. 60 MW represents 97th
percentile of historical generation. However, Avista uses 54 MW for winter capacity and
49 MW for summer capacity based on the QCC values from the Western Resource
Adequacy Program for its resource adequacy planning.