20240723Compliance Filing Cover Letter.pdf

RECEIVED
Tuesday, July 23, 2024
IDAHO PUBLIC
UTILITIES COMMISSION
_ROCKY MOUNTAIN 1407 W.North Temple,Suite 330
4 POWER. Salt Lake City,UT 84116
A DIVISION OF PACIFICORP
July 23, 2024
VIA ELECTRONIC DELIVERY
Commission Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd
Building 8 Suite 201A
Boise, ID 83714
RE: CASE NO. PAC-E-24-01
IN THE MATTER OF THE APPLICATION OF ROCKY MOUNTAIN POWER FOR
APPROVAL OF A CAPACITY DEFICIENCY PERIOD TO BE USED FOR AVOIDED
COST CALCULATIONS
Attention: Commission Secretary
Pursuant to Commission Order No. 36246,Rocky Mountain Power hereby submits its compliance
filing in the above referenced matter.
Commission staff recommended that the company remove all early retirements from the L&R in
the compliance filing, if not already done so.' Order No. 36246 directs the company to submit the
compliance filing as recommended by staff with respect to early coal retirements,before approving
the Company's updated capacity deficiency date.
The Company now presents the attached confidential workpaper with the retirement dates as
approved in Order No. 34754 from the company's most recent depreciation study in Case No.
PAC-E-I8-08.2 Where the depreciation study had an earlier retirement date than the company's
2023 integrated resource plan (2023 IRP)3, the later retirement date was used. This compliance
filing results in the retirement date for Hayden 1 moving from 2029 to 2031 and the retirement
date for Hayden 2 moving from 2028 to 2031. For Colstrip 3, the 2026 retirement date was used
since the company is consolidating its interest in Colstrip 3 into Colstrip 4, such that the overall
capacity remains the same. The retirement date for Colstrip 4 is 2030 which is two years later than
the date approved in the latest depreciation study.
Included with this compliance filing, are also the corrected assumed retirement dates for
Huntington 1 and Huntington 2 from 2043 in the Company's initial filing to 2037, reflecting the
date in the most recent depreciation study.
' See commission staff comments submitted April 291,2024 in Case No.PAC-E-24-01.
2 Retirement dates are presented in Attachment 3 to Order No. 34754.
1 The 2023 IRP was filed with the commission in Case No.PAC-E-23-10.

Idaho Public Utilities Commission
July 23, 2024
Page 2
Informal inquiries may be directed to Mark Alder, Idaho Regulatory Manager at(801) 220-2313.
Very truly yours,
Joe teward
Senior Vice President, Regulation