20230822IPC to Staff 226-231.pdf

LISA D. NORDSTROM
Lead Counsel
[e-mail]

August 22, 2023

VIA ELECTRONIC FILING

Jan Noriyuki, Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd., Bldg 8,
Suite 201-A (83714)
PO Box 83720
Boise, Idaho 83720-0074

Re: Case No. IPC-E-23-11
Idaho Power Company’s General Rate Case

Dear Ms. Noriyuki:

Enclosed for electronic filing, please find Idaho Power Company’s Response to the
Tenth Production Request of the Commission Staff to Idaho Power Company.

Due to the collectively voluminous confidential and non-confidential information
provided in response to data requests in this case, the Company is posting the
attachments to these requests to the secure FTP site to allow parties to view the
requested information remotely unless otherwise noted in the response. Because certain
attachments contain confidential information, the FTP site is divided between confidential
and non-confidential information.

The login information for the non-confidential portion of the FTP site has been
provided to all parties that have intervened to date. The login information for the
confidential portion of the FTP site has been provided to the parties that have executed
the Protective Agreement in this matter.

If you have any questions about the attached filing, please do not hesitate to
contact me.

Very truly yours,
Lisa D. Nordstrom
LDN:sg
Enclosures
RECEIVED
2023 AUGUST 22, 2023 4:43PM
IDAHO PUBLIC
UTILITIES COMMISSION

CERTIFICATE OF ATTORNEY

ASSERTION THAT INFORMATION CONTAINED IN AN IDAHO PUBLIC UTILITIES
COMMISSION FILING IS PROTECTED FROM PUBLIC INSPECTION
Case No. IPC-E-23-11
In the Matter of the Application of Idaho Power Company for Authority to Increase
Its Rates and Charges for Electric Service to Its Customers In the State of Idaho
and For Associated Regulatory Accounting Treatment

The undersigned attorney, in accordance with Commission Rules of Procedure 67,
believes that some of the attachments in Response to Requests Nos. 227, 228, and 229,
to Idaho Power Company’s Response to the Tenth Production Request of the
Commission Staff dated August 22, 2023, contain information that Idaho Power Company
claims are trade secrets and/or business records of a private enterprise required by law
to be submitted to or inspected by a public agency as described in Idaho Code § 74-101,
et seq., and/or § 48-801, et seq. As such, it is protected from public disclosure and exempt
from public inspection, examination, or copying.

DATED this 22nd day of August, 2023.

LISA D. NORDSTROM
Counsel for Idaho Power Company

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 1
LISA D. NORDSTROM (ISB No. 5733)
DONOVAN E. WALKER (ISB No. 5921)
MEGAN GOICOECHEA ALLEN (ISB No. 7623)
Idaho Power Company
1221 West Idaho Street (83702)
P.O. Box 70
Boise, Idaho 83707
Telephone: [phone]
Facsimile: [phone]
[e-mail]
[e-mail]
[e-mail]

Attorneys for Idaho Power Company

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION

IN THE MATTER OF THE
APPLICATION OF IDAHO POWER
COMPANY FOR AUTHORITY TO
INCREASE ITS RATES AND CHARGES
FOR ELECTRIC SERVICE IN THE
STATE OF IDAHO AND FOR
ASSOCIATED REGULATORY
ACCOUNTING TREATMENT.
)
)
)
)
)
)
)
)

CASE NO. IPC-E-23-11

IDAHO POWER COMPANY’S
RESPONSE TO THE TENTH
PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO
POWER COMPANY

COMES NOW, Idaho Power Company (“Idaho Power” or “Company”), and in
response to the Tenth Production Request of the Commission Staff (“Commission” or
“Staff”) dated August 15, 2023, herewith submits the following information:

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 2
REQUEST FOR PRODUCTION NO. 226: Please explain the source and method
for determining the hard-coded numbers included in tab "Inputs" of Brady's workpaper,
"Brady Workpaper 1 — Revenue Forecast Workbook." Please include any workpapers
with formula enabled used to determine the amounts.
RESPONSE TO REQUEST FOR PRODUCTION NO. 226: The first section of the
input tab (rows 12 – 367) is 2022 actual billing data and is collected from monthly billing
reports. The second section of the input tab (rows 373 – 422) is 2022 actual customer
counts and is also collected from monthly billing reports. Both datasets are collected and
maintained throughout the year in a workbook, which was provided as Confidential
Attachment 2 in the Company’s response to Request No. 119. Billing data comes from
the “Actuals” tab of the workbook and customer counts comes from the “NCUST Sorted
– SUMMARY” tab.1
The remaining sections (rows 428 – 535) are forecast data for the 2023 test year
(customer counts, sales, and special contract demand). The workpapers and methods
used to determine the 2023 forecast data are provided in the Company’s responses to
Request Nos. 75 – 80, as well as in the workpaper of Matthew T. Larkin.
The response to this Request is sponsored by Jessi Brady, Regulatory Analyst,
Idaho Power Company.

1 19S 2022 actuals were adjusted due to only containing one customer, which switched from 9S to 19S in mid-2022.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 3
REQUEST FOR PRODUCTION NO. 227: Please explain the source and method
for determining the hard-coded numbers included in tab "Inputs" of Brady's workpaper,
"Brady Workpaper 2 — Proposed Billing Determinants." Please include all workpapers
with formula enabled used to determine the amounts.
RESPONSE TO REQUEST FOR PRODUCTION NO. 227: The input data used in
Brady Workpaper 2 – Proposed Billing Determinants are the same as those described in
the Company’s response to Request No. 226, with the exception of 2022 actuals (rows
12 – 225). Data in rows 12 – 225 are either 2022 billing data and did not change from
Workpaper 1 (highlighted in red) or 2022 usage data according to the proposed rate
structure (highlighted in orange).
Page 9 of the workpaper of Matthew T. Larkin describes the process for collecting
2022 actual usage data according to the Company’s proposed rate structure, which
includes modifying the months considered to be “summer” and “non-summer”, as well as
the time-of-use periods for certain time variant rate classes.
Please see the confidential attachment provided with this response for the
workpaper containing the 2022 usage data included in Brady Workpaper 2 – Proposed
Billing Determinants.
The response to this Request is sponsored by Jessi Brady, Regulatory Analyst,
Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 4
REQUEST FOR PRODUCTION NO. 228: Please provide the derivation, an
explanation of the derivation, and the data used to determine the hard-coded numbers
included in tab "Annual Input" of the workpaper, "Confidential Attachment 2 — Response
to Staff Request No. 119" provided in Company's response to Staff's Production Request
No. 119. Please include all workpapers with formula enabled used to determine the
amounts.
RESPONSE TO REQUEST FOR PRODUCTION NO. 228: Please see
Confidential Attachment 1 provided with this response for 2022 actual and weather
normalized energy by rate schedule. Because the weather adjustment calculation is
handled and stored in the Company’s Oracle environment, an Excel version (with
formulas intact) of the calculation is not available. However, the Company has provided
documentation on how the weather adjustment models are specified in Attachment 2
provided with this response.
Please note that the actual and normalized data for 2022 sales is slightly different
than what was provided in Confidential Attachment 2 – Response to Staff Request No.
119. The Company found a small error in the 2022 normalized data provided in Staff
Request No. 119 and has filed corrected versions of those attachments.
The response to this Request is sponsored by Jordan Prassinos, Manager Load
Forecast and Principal Economist, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 5
REQUEST FOR PRODUCTION NO. 229: Please populate the data for January
2023 through July 2023 (or the last month that data is available) for all tabs in the
workpaper "Confidential Attachment 2 —Response to Staff Request No. 119" provided in
Company's response to Staff Production Request No. 119.
RESPONSE TO REQUEST FOR PRODUCTION NO. 229: Please see the
confidential attachment provided with this response. Tabs that rely on a full year of data
and, therefore contain incomplete or no data, have been highlighted gray.
The response to this Request is sponsored by Jessi Brady, Regulatory Analyst,
Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 6
REQUEST FOR PRODUCTION NO. 230: Please provide an updated Cost of
Service Model using the June through August 3CP allocator for peak-load serving
resources that was utilized in the 2011 class cost of service study. Please provide all
workpapers used to determine Cost of Service Model in electronic format with all formulas
intact and enabled.
RESPONSE TO REQUEST FOR PRODUCTION NO. 230: Please see the three
attachments provided for this request.
The Company has provided the exhibits which change due to the use of June
through August to define the summer period, in place of exhibits derived from a June
through September summer definition in the class cost-of-service (“CCOS”) model
provided as exhibits to Goralski testimony:
 Exhibit Nos. 38-43 – “class allocation model”
 Exhibit No. 45 - Development of Weighted Demand and Energy Allocators
 Exhibit No. 46 - Revenue Requirement Adjustments
The 2023 CCOS study filed by the Company utilized a June through August
summer definition for test year sales revenue, Brady Exhibit Nos. 27-28, while CCOS
billing determinants were derived from the proposed June through September summer
definition, Brady Exhibit No. 29. In this response, the CCOS model utilized Brady Exhibit
Nos. 27-28 (June through August summer) for the billing determinants.
Finally, the Company notes the provided attachments were prepared by working
back from the 2023 CCOS submitted with Goralski testimony, unwinding only the 4CP
allocator to 3CP, but leaving the 100 percent capacity classification of baseload
generation-functionalized costs. This varies from the comparative analysis described in

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 7
Goralski testimony which starts with the “2011 rate case” CCOS methodology and layers
on changes individually, such that unchanged variables remain under the 2011 rate case
basis, while in the attachments provided for this response variables not part of the request
remain under the 2023 rate case basis.
The response to this Request is sponsored by Paul Goralski, Regulatory
Consultant, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 8
REQUEST FOR PRODUCTION NO. 231: Please provide an updated Cost of
Service Model using the jurisdictional load factor that was utilized in the 2011 class cost
of service study to classify base-load generation expense. Please provide all workpapers
used to determine Cost of Service Model in electronic format with all formulas intact and
enabled.
RESPONSE TO REQUEST FOR PRODUCTION NO. 231: Please see the three
attachments provided for this request.
In addition to Attachment 1, the Idaho jurisdictional load factor derivation, the
Company has provided the exhibits which change due to the use of the Idaho jurisdictional
load factor to classify baseload generation-functionalized expenses between energy and
capacity, in place of exhibits where baseload generation-functionalized expenses were
classified as 100 percent capacity in the class cost-of-service model provided as exhibits
to Goralski testimony:
 Exhibit No. 37 – Functionalization and Classification of Costs
 Exhibit Nos. 38-43 – “class allocation model”
In validating the input values used to derive Attachment 1, the Company found the
version of the same input file provided as Confidential Attachment 2 in Response to Staff’s
Production Request No. 75 had corrupt formulas for the Residential class in four columns.
Concurrent to filing these responses, the Company is filing a Supplemental Response to
Staff’s Production Request No. 75 to include a version of Confidential Attachment 2 which
corrects for the invalid formulas. There are no differences in values, only correction of the
invalid formulas.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 9
As noted in Response to Request No. 230, the provided attachments were
prepared by working back from the 2023 CCOS submitted with Goralski testimony. In the
attachments for this response only the 100 percent capacity classification of baseload
generation-functionalized costs was unwound, the 4CP allocator remains as it is part of
the 2023 rate case basis.
The response to this Request is sponsored by Paul Goralski, Regulatory
Consultant, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 10
DATED at Boise, Idaho, this 22nd day of August 2023.

LISA D. NORDSTROM
Attorney for Idaho Power Company

DONOVAN E. WALKER
Attorney for Idaho Power Company

MEGAN GOICOECHEA ALLEN
Attorney for Idaho Power Company

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 11
CERTIFICATE OF SERVICE

I HEREBY CERTIFY that on the 22nd day of August 2023, I served a true and
correct copy of Idaho Power Company’s Response to the Tenth Production Request of
the Commission Staff to Idaho Power Company upon the following named parties by the
method indicated below, and addressed to the following:

Commission Staff
Dayn Hardie
Chris Burdin
Deputy Attorney General
Idaho Public Utilities Commission
11331 W. Chinden Blvd., Bldg No. 8
Suite 201-A (83714)
PO Box 83720
Boise, ID 83720-0074

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
[e-mail]

Clean Energy Opportunities for Idaho
Kelsey Jae
Law for Conscious Leadership
920 N. Clover Dr.
Boise, ID 83703
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

Courtney White
Mike Heckler
Clean Energy Opportunities for Idaho
3778 Plantation River Drive, Suite 102
Boise, ID 83703

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email
[e-mail]
[e-mail]

Industrial Customers of Idaho Power
Peter J. Richardson
Richardson Adams, PLLC
515 N. 27th Street
Boise, Idaho 83702

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 12
Dr. Don Reading
280 Silverwood Way
Eagle, Idaho 83616

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

Idaho Irrigation Pumpers Association,
Inc.
Eric L. Olsen
ECHO HAWK & OLSEN, PLLC
505 Pershing Avenue, Suite 100
P.O. Box 6119
Pocatello, Idaho 83205

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

Lance Kaufman, Ph.D.
2623 NW Bluebell Place
Corvallis, OR 97330
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

Micron Technology, Inc.
Austin Rueschhoff
Thorvald A. Nelson
Austin W. Jensen
Holland & Hart, LLP
555 Seventeenth Street, Suite 3200
Denver, Colorado 80202

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
[e-mail]
[e-mail]
[e-mail]
[e-mail]

Jim Swier
Micron Technology, Inc.
8000 South Federal Way
Boise, Idaho 83707
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 13
City of Boise
Ed Jewell
Darrell Early
Boise City Attorney’s Office
150 N. Capitol Blvd.
Boise, ID 83701
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
[e-mail]
[e-mail]

Wil Gehl
Boise City Dept. of Public Works
150 N. Capitol Blvd.
P.O. Box 500
Boise, Idaho 83701-0500

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

Idaho Conservation League
Marie Callaway Kellner
Idaho Conservation League
710 N. 6th Street
Boise, Idaho 83702

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]

Brad Heusinkveld
Idaho Conservation League
710 N. 6th Street
Boise, Idaho 83702
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email
[e-mail]

IdaHydro
C. Tom Arkoosh
Arkoosh Law Offices
913 W. River Street, Suite 450
P.O. Box 2900
Boise, Idaho 83701

Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
[e-mail]

IDAHO POWER COMPANY’S RESPONSE TO THE TENTH PRODUCTION REQUEST OF THE
COMMISSION STAFF - 14
Federal Executive Agencies
Peter Meier
Paige Anderson
Tanner Crowther
U.S. Department of Energy
1000 Independence Ave., S.W.
Washington, DC 20585
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
Dwight Etheridge
Exeter Associates
5565 Sterrett Place, Suite 310
Columbia, MD 21044
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
NW Energy Coalition
F. Diego Rivas
1101 8th Ave
Helena, MT 59601
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
Walmart Inc.
Norman M. Semanko
Parsons Behle & Latimer
800 West Main Street, Suite 1300
Boise, Idaho 83702
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
Steve W. Chriss
Director, Energy Services
Walmart Inc.
2608 Southeast J Street
Bentonville, Arkansas 72716
Hand Delivered
U.S. Mail
Overnight Mail
FAX
FTP Site
X Email [e-mail]
Stacy Gust, Regulatory Administrative
Assistant