20231116IPC to Staff 5-6.pdf

MEGAN GOICOECHEA ALLEN
Corporate Counsel
[e-mail]

November 16, 2023

VIA ELECTRONIC MAIL

Jan Noriyuki, Secretary
Idaho Public Utilities Commission
11331 West Chinden Blvd., Building 8
Suite 201-A
Boise, Idaho 83714

Re: Case No. IPC-E-23-25
Idaho Power Company’s Annual Compliance Filing to Update the Load and
Gas Forecast in the Incremental Cost Integrated Resource Plan Avoided
Cost Model

Dear Ms. Noriyuki:

Attached for electronic filing is Idaho Power Company’s Response to the Second
Production Request of the Commission Staff to Idaho Power Company in the above-
entitled matter.

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

Very truly yours,
Megan Goicoechea-Allen

MGA:cld
Enclosures
RECEIVED
Thursday, November 16, 2023 3:50:21 PM
IDAHO PUBLIC
UTILITIES COMMISSION
IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION
REQUEST OF THE COMMISSION STAFF - 1
MEGAN GOICOECHEA ALLEN (ISB No. 7623)
DONOVAN E. WALKER (ISB No. 5921)
Idaho Power Company
1221 West Idaho Street (83702)
P.O. Box 70
Boise, Idaho 83707
Telephone: [phone]
Facsimile: [phone]
[e-mail]
[e-mail]

Attorneys for Idaho Power Company

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION

IDAHO POWER COMPANY’S ANNUAL
COMPLIANCE FILING TO UPDATE THE
LOAD AND GAS FORECASTS IN THE
INCREMENTAL COST INTEGRATED
RESOURCE PLAN AVOIDED COST
MODEL.
)
)
)
)
)
)
)
)

CASE NO. IPC-E-23-25

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

COMES NOW, Idaho Power Company (“Idaho Power” or “Company”), and in
response to the Second Production Request of the Commission Staff (“Commission” or
“Staff”) dated November 9, 2023, herewith submits the following information:
IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION
REQUEST OF THE COMMISSION STAFF - 2
STAFF REQUEST FOR PRODUCTION NO. 5: Please respond to the following
regarding the proposed load.
a. When was the proposed load created?
b. Please confirm that the proposed load is based on 70th percentile of load;
c. Please explain why and how the Company determined that the 70th percentile
energy load forecast was the right level to use for its planning case. Please provide
evidence and any workpapers to explain the answer;
d. Please provide the timeframe of load data used to develop the load forecast;
e. Please explain how the load data was collected; and
f. Please explain what "70th percentile" means.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 5:
a. The proposed load forecast represented in IPC-E-23-25 was developed in the third
quarter of 2023.
b. No, the proposed load forecast within IPC-E-23-25 is not based on the 70th
percentile of load. It is consistent with previous filings and represents the 50th
percentile of load.
c. As noted in part b, the Company did not use the 70th percentile forecast for this
filing.
d. The Company uses several different ordinary least squares (“OLS”) models and a
statistically-adjusted end-use (“SAE”) model segmented by customer class. As
such, each may represent a slightly different training period of historical data. In
general, most OLS models use 20-years of history while the residential customer
class, the sole SAE model, uses approximately 15-years of historical data.
IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION
REQUEST OF THE COMMISSION STAFF - 3
e. The models discussed in d. have a left-hand side, or dependent variable, of billed
sales. Historical data is collected through the company’s billing month metered
data.
f. As noted in b. the Company did not use the 70th percentile in development of the
filing represented in docket IPC-E-23-25. However, for context, the 70th percentile
would represent the different weather percentiles for weather-sensitive customer
classes.
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 SECOND PRODUCTION
REQUEST OF THE COMMISSION STAFF - 4
STAFF REQUEST FOR PRODUCTION NO. 6: Please explain what percentile of
load was used in Case No. IPC-E-22-26. If the percentile was different than the percentile
proposed in this case, please quantify the difference between the two load forecasts due
to the different percentiles.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 6: As noted in the
Company’s response to 5b. the Company used the 50th percentile in both Case No. IPC-
E-22-26 and Case No. IPC-E-23-25. The reconciliation of the differences of the forecasts
of the different case numbers would be consistent with the information included within the
Company’s filing in IPC-E-23-25.
The response to this Request is sponsored by Jordan Prassinos, Manager Load
Forecast and Principal Economist, Idaho Power Company.

Respectfully submitted this 16th day of November 2023.

Megan Goicoechea Allen
Attorney for Idaho Power Company
IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION
REQUEST OF THE COMMISSION STAFF - 5
CERTIFICATE OF SERVICE

I HEREBY CERTIFY that on this 16th day of November 2023, I served a true and
correct copy of the within and foregoing IDAHO POWER COMPANY’S RESPONSE TO
THE SECOND PRODUCTION REQUEST OF THE COMMISSION STAFF upon the
following named parties by the method indicated below, and addressed to the following:

Adam Triplett
Deputy Attorneys General
Idaho Public Utilities Commission
P.O. Box 83720
Boise, ID 83720-0074

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

________________________________
Christy Davenport, Legal Assistant