20240131Compliance Filing.pdf

Avista Corp.
1411 East Mission P.O. Box 3727
Spokane. Washington 99220-0500
Telephone [phone]
Toll Free 800-727-9170

January 31, 2024

Commission Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd. Bldg. 8, Ste. 201-A
Boise, Idaho 83714

RE: Case No. AVU-E-23-12 Compliance Filing - Capacity Deficiency Period for the Avoided
Cost Calculations

Dear Commission Secretary:

Avista Corporation, dba Avista Utilities (Avista or the Company), submits its compliance filing in
accordance with Order No. 36056 in Case No. AVU-E-23-12, regarding Avista’s updated capacity
deficiency period to be used for avoided cost calculations.

Order No. 36056 requires the Company to do the following:

1) “… file an updated L&R as a compliance filing using the Company’s Traditional Method for
deriving it by using the most current peak load forecasts for both winter and summer.”

2) “… demonstrate that the method and inputs used to derive the Company’s QCC values reflect
the generation capacity of the Company’s resources relative to the peak loads within the
Company’s system prior to the next capacity deficiency update.”

3) “… develop its PRM driven by the Company’s reliability target and appropriately developed
capacity contribution factor system prior to the next capacity deficiency update.”

As mentioned in the Company’s November 16, 2023, comments in this case, Avista is working
with Applied Energy Group (AEG) to develop an end use load forecast to use in resource planning.
The first version of the peak load forecast developed under this methodology was originally
expected to be available toward the end of November 2023. This forecast started with the
Company’s most recent 5-year load forecast along with long term projections of energy use given
projected customer growth and technology availability. The initial forecast from AEG needed
additional work and adjustments before it could be considered for use in the Company’s resource
RECEIVED
Wednesday, January 31, 2024 3:53PM
IDAHO PUBLIC
UTILITIES COMMISSION

2 | P a g e

planning needs. Several questions and concerns needed to be addressed with AEG, which was not
unexpected considering this is the first time this type of end use load forecast has been developed
for Avista. After quite a bit of discussion and reconfiguration of AEG’s model, an updated forecast
from AEG was received on January 29, 2024. The Company has had little time to review this load
forecast but has met with AEG to review the forecast. Avista will receive an updated load forecast
in March 2024 for use in its 2025 IRP to be filed on January 2, 2025, using updated assumptions.

The new forecast shows higher growth rates in the summer and lower growth rates in the winter
peaks compared to the previous forecast. As provided in Figure 1 below, the winter capacity deficit
position moves from 2034 to 2036 and Figure 2 provides the update to the summer capacity deficit
which moves from 2037 to 2036.

The table below is the estimated megawatt peak values from the new peak load forecast.

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2025 1,709 1,595 1,459 1,303 1,513 1,594 1,747 1,724 1,404 1,507 1,683 1,727
2026 1,714 1,599 1,465 1,309 1,523 1,589 1,746 1,730 1,408 1,512 1,687 1,732
2027 1,732 1,615 1,480 1,325 1,544 1,604 1,759 1,748 1,422 1,528 1,703 1,746
2028 1,746 1,633 1,500 1,341 1,563 1,613 1,782 1,775 1,442 1,535 1,708 1,754
2029 1,754 1,640 1,507 1,348 1,570 1,633 1,803 1,792 1,459 1,545 1,719 1,763
2030 1,763 1,650 1,518 1,358 1,582 1,647 1,817 1,819 1,472 1,552 1,726 1,774
2031 1,774 1,661 1,526 1,369 1,598 1,667 1,837 1,826 1,486 1,563 1,738 1,787
2032 1,787 1,672 1,540 1,383 1,610 1,700 1,856 1,848 1,505 1,581 1,755 1,801
2033 1,801 1,688 1,557 1,402 1,630 1,715 1,876 1,862 1,521 1,595 1,768 1,816
2034 1,816 1,705 1,573 1,416 1,644 1,749 1,899 1,891 1,545 1,614 1,789 1,833
2035 1,833 1,726 1,594 1,436 1,667 1,763 1,930 1,925 1,572 1,630 1,808 1,851
2036 1,851 1,744 1,612 1,456 1,689 1,794 1,960 1,967 1,599 1,647 1,824 1,868
2037 1,868 1,764 1,630 1,476 1,709 1,815 1,988 1,992 1,624 1,664 1,840 1,886
2038 1,886 1,782 1,649 1,496 1,732 1,852 2,026 2,033 1,656 1,686 1,859 1,906
2039 1,906 1,802 1,671 1,517 1,755 1,875 2,062 2,061 1,686 1,707 1,879 1,928
2040 1,928 1,823 1,693 1,540 1,780 1,911 2,097 2,097 1,723 1,726 1,894 1,951
2041 1,951 1,845 1,714 1,562 1,801 1,930 2,136 2,140 1,762 1,750 1,919 1,977
2042 1,977 1,871 1,741 1,588 1,828 1,959 2,171 2,184 1,801 1,776 1,943 2,005
2043 2,005 1,898 1,770 1,615 1,857 1,992 2,207 2,231 1,841 1,804 1,971 2,037
2044 2,037 1,929 1,804 1,647 1,890 2,049 2,254 2,282 1,891 1,839 2,000 2,071
2045 2,071 1,967 1,842 1,684 1,928 2,104 2,307 2,344 1,945 1,842 2,001 2,071

3 | P a g e

Figure No. 1 – Winter One-Hour Capacity Load & Resources

Figure No. 2 – Summer One-Hour Capacity Load & Resources

The attached CONFIDENTIAL workpapers contain the calculations for deriving the updated
L&Rs. Avista will work on demonstrating the other two issues regarding the Company’s QCC and
PRM values for use in its 2025 IRP process and subsequent capacity deficiency filing.

4 | P a g e

Sincerely,

/s/Shawn Bonfield

Shawn Bonfield
Sr. Manager of Regulatory Policy & Strategy
Avista Utilities
509-495-2782
[e-mail]