20230807IPC to CEO 7-8.pdf

MEGAN GOICOECHEA ALLEN
Corporate Counsel
[e-mail]

August 4, 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
Second Production Request of Clean Energy Opportunities for Idaho 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.

The login information for the non-confidential portion of the FTP site has been
provided to all parties that have intervened to date.

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

Very truly yours,

Megan Goicoechea Allen
MGA:sg
Enclosures
RECEIVED
2023 AUGUST 4, 2023 3:40PM
IDAHO PUBLIC
UTILITIES COMMISSION

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 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.
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CASE NO. IPC-E-23-11

IDAHO POWER COMPANY’S
RESPONSE TO THE SECOND
PRODUCTION REQUEST OF
CLEAN ENERGY OPPORTUNITIES
FOR IDAHO TO IDAHO POWER
COMPANY

COMES NOW, Idaho Power Company (“Idaho Power” or “Company”), and in
response to Clean Energy Opportunities for Idaho’s (“CEO”) Second Production Request
to Idaho Power Company dated July 14, 2023, herewith submits the following information:

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 2
REQUEST FOR PRODUCTION NO. 7:
Please provide both the hourly load and that hour’s loss of load probability, as
estimated by the Company’s Reliability and Capacity Assessment Tool, for all 8760 hours
(or 8788 hours in the leap year data request) in requests 7.1 and 7.2 below.
7.1 If it is possible to load the test year load and resource mix data into the
Reliability and Capacity Assessment Tool, please provide both the load served
each hour and the loss of load probability for each hour of the 2023 test year based
on the load pattern and the resource mix used in Aurora to produce test year
energy pricing data.
7.2 Regardless of whether it is or is not possible to provide the information
requested in 7.1 above, using the load patterns from the years 2017, 2018, 2019,
2020, 2021 and 2022 and Reliability and Capacity Assessment Tool, for each of
the six years please provide the load served each hour and the loss of load
probabilities for each individual hour. Please use the projected 2024 resource mix
when performing the calculations associated with these six years of load data.
RESPONSE TO REQUEST FOR PRODUCTION NO. 7:
7.1 For context, the highest-risk hours calculated by the Reliability and Capacity
Assessment Tool (“RCAT”) for defining the proposed Time of Use (“TOU”) periods
in the case were based on the 2025 load and resource year. 2025 was selected to
reflect the impact of increasing loads and renewable generation saturation. The
RCAT currently utilizes 6 years of historical hourly data (2017-2022), adjusted for
daylight savings and leap years, to maintain the relationship between weather,
load, and renewable generation. The Company adjusts historical load for demand

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 3
response and evaluates loss of load expectation on an annual basis, so the 2023
historical hourly data will not be available for use in the RCAT until 2024. The
historical hourly load is adjusted to reflect the forecasted monthly 70th percentile
peak loads. This approach allows Idaho Power to capture the varying weather
conditions that can occur from year to year while also forecasting the expected
value of future years.
If Idaho Power were to use the hourly load pattern and resource data from
the referenced Aurora model in the RCAT, it is expected the tool would produce
significantly different results because simulated data does not capture the
relationship between weather, load and renewable generation as historical data
does. Further, the RCAT is a capacity model and does not consider energy pricing
data.
Per discussions with CEO for this request, Idaho Power agreed to
incorporate the historical hourly load (scaled in combination with the 2023 peak
load forecast) and renewable generation data for 2023 into the RCAT, and the
simulations were rerun for all 6 years. Please see “Attachment – Response to
CEO’s Request No. 7.1” for the forecasted system load, loss of load probabilities
and resource mix for the 2023 load and resource year.
7.2 As described in the response to request 7.1, the highest-risk hours calculated by
the RCAT for defining proposed TOU periods were based on the 2025 load and
resource year. For this request, the historical hourly load and renewable
generation data for 2024 was incorporated into the RCAT and the simulations were
rerun for all 6 years. Please see “Attachment – Response to CEO’s Request No.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 4
7.2” for the forecasted system load, loss of load probabilities and resource mix for
the 2024 load and resource year.
The response to this Request is sponsored by Jared Ellsworth, Transmission,
Distribution & Resource Planning Director, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 5
REQUEST FOR PRODUCTION NO. 8:
Referring again to the workshop presented on July 12, 2023 and the slide 20
reference to rate design objectives associated with aligning seasonal and TOU periods
with “highest risk hours”:
8.1 Does the Company use, in any way, the hourly loss of load probabilities output
from the Company’s Reliability and Capacity Assessment Tool in identifying which
are the “highest risk hours”?
8.2 If the Company does in any way utilize output from the Company’s Reliability
and Capacity Assessment Tool in identifying which are the “highest risk hours”, is
there a threshold value or sum of such probability values that characterize the loss
of load probability for a particular hour or period of consecutive hours as being
within the “highest risk” category?
RESPONSE TO REQUEST FOR PRODUCTION NO. 8:
8.1 Yes, the hourly Loss of Load Probabilities (“LOLPs”) calculated by the Reliability
and Capacity Assessment Tool (“RCAT”) were utilized to identify the highest-risk
hours for the proposed Time of Use (“TOU”) periods.
8.2 Yes, the proposed TOU periods’ highest-risk hours were developed utilizing set
thresholds. Please see “Attachment – Response to CEO’s Request No. 8.2” for
the data and plots that support the following process descriptions.
a. First, the hourly LOLPs were calculated for each of the 6 years as explained
in response to request 7.1 (see “LOLP” tab).
b. The hourly LOLPs were then separated by month for each of the 6 years
and displayed in the form of a heatmap. The hourly LOLPs for each

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 6
individual month were sorted from highest risk to lowest risk (descending
order), and the risk threshold is set to 50 percent. For example, if the sum
of all of the LOLPs in the month of July equals 0.07, then the highest risk
hours are added together until they equal 0.035. The number of hours
(number of hours equals “X”) it takes to reach the 50 percent threshold can
change by month and by test year. The resulting “X” LOLPs and their
corresponding hour of occurrence represents the 50 percent risk threshold
distribution for the highest-risk hours in a specified month (see “Summer”
and “Winter” tabs).
c. The 50 percent risk threshold distribution results for each of the 6 test years
were then combined to show in what hour of the day the overall highest-risk
hours were occurring in a particular month. The percent of occurrences data
was directly used to determine the highest-risk hours. The highest-risk
consecutive hours were determined by taking the percentage of
occurrences greater than 15 percent for the summer months and the
percentage of occurrences greater than 10 percent for the winter months
(see “TOU_Results” tab).
The response to this Request is sponsored by Jared Ellsworth, Transmission,
Distribution & Resource Planning Director, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 7
DATED at Boise, Idaho, this 4th day of August 2023.

MEGAN GOICOECHEA ALLEN
Attorney for Idaho Power Company

DONOVAN E. WALKER
Attorney for Idaho Power Company

LISA D. NORDSTROM
Attorney for Idaho Power Company

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 8
CERTIFICATE OF SERVICE

I HEREBY CERTIFY that on the 4th day of August 2023, I served a true and correct
copy of Idaho Power Company’s Response to the Second Production Request of Clean
Energy Opportunities for Idaho 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

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Clean Energy Opportunities for Idaho
Kelsey Jae
Law for Conscious Leadership
920 N. Clover Dr.
Boise, ID 83703
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Courtney White
Mike Heckler
Clean Energy Opportunities for Idaho
3778 Plantation River Drive, Suite 102
Boise, ID 83703

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

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IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 9
Dr. Don Reading
280 Silverwood Way
Eagle, Idaho 83616

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

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Lance Kaufman, Ph.D.
2623 NW Bluebell Place
Corvallis, OR 97330
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Micron Technology, Inc.
Austin Rueschhoff
Thorvald A. Nelson
Austin W. Jensen
Holland & Hart, LLP
555 Seventeenth Street, Suite 3200
Denver, Colorado 80202

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Jim Swier
Micron Technology, Inc.
8000 South Federal Way
Boise, Idaho 83707
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IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 10
City of Boise
Ed Jewell
Darrell Early
Boise City Attorney’s Office
150 N. Capitol Blvd.
Boise, ID 83701
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Wil Gehl
Boise City Dept. of Public Works
150 N. Capitol Blvd.
P.O. Box 500
Boise, Idaho 83701-0500

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

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Brad Heusinkveld
Idaho Conservation League
710 N. 6th Street
Boise, Idaho 83702
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IdaHydro
C. Tom Arkoosh
Arkoosh Law Offices
913 W. River Street, Suite 450
P.O. Box 2900
Boise, Idaho 83701

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Federal Executive Agencies
Peter Meier
c/o U.S. Department of Energy
1000 Independence Ave., S. W.
Washington, DC 20585
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IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF CLEAN
ENERGY OPPORTUNITIES FOR IDAHO TO IDAHO POWER COMPANY - 11
Dwight Etheridge
Exeter Associates
5565 Sterrett Place, Suite 310
Columbia, MD 21044
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NW Energy Coalition
F. Diego Rivas
1101 8th Ave
Helena, MT 59601
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Stacy Gust, Regulatory Administrative
Assistant