20231205IPC to Staff 1-19.pdf

MEGAN GOICOECHEA ALLEN
Corporate Counsel
[e-mail]

December 5, 2023

VIA ELECTRONIC MAIL

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

Re: Case No. IPC-E-23-27
Idaho Power Company’s Application for Approval of the Capacity Deficiency
Period to be Utilized for Avoided Cost Calculations

Dear Commission Secretary:

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

The confidential attachment will be sent in a separate email to the parties who sign
the Protective Agreement.

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

Very truly yours,
Megan Goicoechea Allen

MGA:cd
Enclosures
RECEIVED
Tuesday, December 5, 2023 3:43:30 PM
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-23-27
Idaho Power Company’s Application for Approval of the Capacity Deficiency
Period to be Utilized for Avoided Cost Calculations

The undersigned attorney, in accordance with Commission Rules of Procedure 67,
believes that the Attachment No. 1 to Idaho Power Company’s Response to the First
Production Request of the Commission Staff to Idaho Power Company dated December
5, 2023, may contain information that Idaho Power Company and a third party claims is
a confidential trade secrets and 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 Tuesday, December 5, 2023,

Megan Goicoechea Allen
Counsel for Idaho Power Company

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

IN THE MATTER OF IDAHO POWER
COMPANY’S APPLICATION FOR
APPROVAL OF THE CAPACITY
DEFICIENCY PERIOD TO BE UTILIZED
FOR AVOIDED COST CALCULATIONS.
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CASE NO. IPC-E-23-27

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

COMES NOW, Idaho Power Company (“Idaho Power” or “Company”), and in
response to the First Production Request of the Commission Staff (“Commission” or
“Staff”) dated November 14, 2023, herewith submits the following information:
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 2
STAFF REQUEST FOR PRODUCTION NO. 1: Page 4 of the Application states
that the Company uses the most recent, relevant, and accurate information available in
this case. Please respond to the following regarding the load forecast used.
a. Please explain when the load forecast was created;
b. Please compare the load forecast used in this case and the load forecast used in
the last capacity deficiency case (Case No. IPC-E-21-09) that determined a 2023
first deficit year and explain the difference between the two forecasts;
c. Please provide the workpapers that compare the two forecasts; and
d. Please explain what causes any difference.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 1: Please see the
responses below:
a. The load forecast used in this case was created in the second quarter of 2023 to
be used in the Company’s 2023 Integrated Resource Plan (referred to hereafter
as the “2023 IRP Forecast”).
b. The load forecast used in the last capacity deficiency case was used in the
Company’s 2019 Integrated Resource Plan (referred to hereafter as the “2019 IRP
Forecast”). When compared to the 2019 IRP Forecast, the 2023 IRP Forecast
resulted in a 639 MW increase in the Company’s 50th-percentile system peak by
2038. This difference is primarily due to an increase in forecasted Additional Firm
Load, or Energy Service Agreement (“ESA”), load requirements.
c. Please see the Excel file labeled “CONFIDENTIAL Attachment 1 - Response to
Staff Request for Production No. 1.xlsx” for a workpaper comparing the two
forecasts.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 3
d. For comparison purposes, the differences between the 50th-percentile 2019 IRP
Forecast and 50th-percentile 2023 IRP Forecast are referenced in this response.
Any variances due to resource margin method changes are not reflected in this
comparison. Compared to the 2019 IRP Forecast, residential load increased by an
average of approximately 25 aMW per year due to higher than expected customer
growth. When combined, there was substantially no change in Commercial and
Industrial load between the two forecasts. Irrigation load decreased by a minimal
amount (an average of approximately 10 aMW per year). The primary difference
between the two forecasts is associated with ESA customer load. Relative to the
2019 IRP Forecast, the 2023 IRP Forecast incorporates the addition/expansion of
two ESA customers: Meta Platforms, Inc. (Meta) and Micron Technology, Inc.
(Micron), who are both building new, large facilities in Idaho Power’s service area.
Detail is provided in the confidential attachment included for part C.
The response to this Request is sponsored by Jordan Prassinos, Load Forecast
Manager and Principal Economist, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 4
STAFF REQUEST FOR PRODUCTION NO. 2: Please respond to the following
questions regarding Figure No. 1 shown during Portfolio Reliability Analysis presentation
in the August 15, 2023, Integrated Resource Plan Advisory Council meeting.
Figure No. 1 Reliability & Capacity Assessment Tool ("RCAT") Modeling Flowchart

a. Please explain how "System Adjusted Load" is determined;
b. Please explain the test years used to determine the capacity deficiency, why these
test years were selected, and how test years are adjusted to align with the monthly
peak of each forecasted Load and Resource ("L&R") year over the planning
horizon;
c. Please explain whether the adjustments used to align with each forecasted L&R
year occurs to each year throughout the entire planning horizon;
d. Please explain if such adjustments take place before the step of netting out the
capacity of "Run of Rivers", "Variable Energy Resources", "Cogeneration & Small
Power Production" in Figure No. 1. If not, where are these adjustments located in
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 5
Figure No. 1; and
e. Please explain how "net load" is derived and how the amounts of "Run of Rivers",
"Variable Energy Resources", "Cogeneration & Small Power Production" are
determined. Do the amounts depend on the test years and the alignment of test
years to the L&R years?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 2: Please see the
responses below:
a. The system adjusted load is determined by adding the dispatched demand
response during a given year to the system load. 𝑆𝑦𝑠𝑡𝑒𝑚 𝐴𝑑𝑗𝑢𝑠𝑡𝑒𝑑 𝐿𝑜𝑎𝑑=𝑆𝑦𝑠𝑡𝑒𝑚 𝐿𝑜𝑎𝑑+𝐷𝑒𝑚𝑎𝑛𝑑 𝑅𝑒𝑠𝑝𝑜𝑛𝑠𝑒 𝐷𝑖𝑠𝑝𝑎𝑡𝑐ℎ𝑒𝑑
b. The Company utilizes six test years of historical hourly data to maintain the
relationship between weather, load, and Variable Energy Resource (“VER”)
generation. The test years range from the most recently available data of 2022
back to 2017, when the first utility-scale solar plant came online and delivered
generation to Idaho Power. The test year hourly load is adjusted by scaling each
month individually such that each month in a test year has the same peak as the
forecasted monthly peak for a given Load and Resource (“L&R”) year. The annual
capacity position of a particular L&R year is calculated for each of the six test years
and then averaged to determine the Company’s first year of capacity deficiency.
c. Yes, the adjustments to the test year hourly load are performed for each L&R year
throughout the planning horizon.
d. Yes, the adjustments to the test year hourly load take place before any resources
are netted out.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 6
e. The net load is derived by taking a test year’s system-adjusted load and
subtracting all the generation (from the same test year) that Idaho Power does not
control on an hour-by-hour basis (such as run-of-river hydro, wind, solar, and
cogeneration and small power production); the historical data of these resources
is scaled up or down depending on additions and/or retirements in any given L&R
year. For more information on how the net load is calculated, please see the
“Reliability & Capacity Assessment” video on the Educational Resources webpage
of Idaho Power’s 20-Year Plan.1
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.

1 Idaho Power 20-Year Plan Educational Resources (starting at minute 20)
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 7
STAFF REQUEST FOR PRODUCTION NO. 3: Please respond to the following
regarding the annual capacity position of each test year.
a. Please confirm that the annual capacity position of each test year is the amount of
capacity needed during hours of highest risks;
b. Does each year in the entire planning horizon have different hours of highest risks?
Please explain;
c. Please explain how hours of highest risks are identified and provide a workpaper
to illustrate the process; and
d. Please explain how annual capacity positions are determined based on hours of
highest risks and provide a workpaper to illustrate the process.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 3: Please see the
responses below:
a. No, the annual capacity position of each test year does not represent the amount
of capacity needed during the hours of highest risk. The annual capacity position
(which is an average across six test years) is the amount of perfect capacity that
corresponds to achieving a Loss of Load Expectation (“LOLE”) of 0.1 event-days
per year. The hours of highest risk can be derived from the LOLE analysis. In the
event of a capacity shortfall, the timing of highest risk analysis helps determine
which hours need to be targeted for capacity additions and best achieve the
desired LOLE threshold.
b. As the hours of highest risk and annual capacity positions are both derived from
the LOLE analysis, yes, there is potential that the hours of highest risk could vary
by Load and Resource (“L&R”) year. The hours of highest risk and annual capacity
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 8
positions are functions of the system buildout in a particular L&R year. The addition
and/or retirement of generation resources (especially Variable Energy Resources
(“VERs”) and Energy Limited Resources (“ELRs”)) and load shape impact the
hours of highest risk in any given L&R year.
c. Please see the Timing of Highest Risk section in Appendix C of the 2023 Integrated
Resource Plan for information on how the hours of highest risk are determined.
For more in-depth information about how the hours of highest risk are determined
please see the attachment to this request, which provides responses to discovery
requests No. 4 through No. 8 in Case No. IPC-E-23-23.
d. As stated in part a. of this response, the annual capacity positions are not
determined based on the hours of highest risk.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 9
STAFF REQUEST FOR PRODUCTION NO. 4: Please respond to the following
regarding the Effective Load-Carrying Capability ("ELCC") results listed on Page 92 of
Appendix C of the 2023 Integrated Resource Plan ("IRP").
a. The results include "ELCC of Existing and Expected Resources" and "ELCC of
Future Resources." Please explain the difference between "Expected Resources"
and "Future Resources."
b. Is "ELCC of Future Resources" used in this case? If so, please explain why they
are appropriate for establishing the first capacity deficiency date.
c. Is the "ELCC of Existing and Expected Resources" used in this case? If so, please
explain how it is used.
d. Is the "ELCC of Existing and Expected Resources" used to determine the amount
of "Run of Rivers", "Variable Energy Resources", "Cogeneration & Small Power
Production" capacity reflected in Figure No. 1 above?
e. Please explain how "ELCC of Existing and Expected Resources" and "ELCC of
Future Resources" are determined and whether there is a difference between the
two methods.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 4: Please see the
responses below:
a. “Expected Resources” are resources that are under contract and/or expected to
come online in the near-term but not yet in service. “Future Resources” are
resources that do not have a contract.
b. The values provided on page 92 of Appendix C under “ELCC of Future Resources”
were not utilized in this case and were provided for informational purposes. Only
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 10
resources under contract and/or expected to come online in the near term are
utilized in the determination of the capacity deficiency date.
c. The values provided on page 92 of Appendix C under “ELCC of Existing and
Expected Resources” were not utilized in this case and were provided for
informational purposes.
d. ELCC values are not used to calculate capacity positions, meaning they do not
inform the deficiency date. ELCC values are an output of the Company’s Reliability
and Capacity Assessment Tool (“RCAT”), not an input.
e. Both the “ELCC of Existing and Expected Resources” and the “ELCC of Future
Resources” are calculated using the “last-in” ELCC methodology.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 11
STAFF REQUEST FOR PRODUCTION NO. 5: Please list all the resources used
in the L&R Balance by resource type (i.e. coal, natural gas, hydro, solar, wind, storage,
market purchases, etc.) and for each resource, provide the following information.
a. Please provide the first operation date for any new resource included in the L&R
balance across the 20-year planning horizon since the last deficit date case was
filed;
b. Please provide the exit/retirement dates for any resource that exits or retires at any
point during the 20-year planning horizon in the L&R balance; and
c. Please list all the coal units that are assumed to be converted to gas in the L&R
balance and when each assumed conversion occurs.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 5: Please see the
responses below:
a. For clarification, Idaho Power has replaced the traditional Load and Resource
Balance with the annual capacity position analysis (as derived through the Loss of
Load Expectation methodology). Please see the Excel file labeled “Attachment –
Response to Staff Request for Production No. 5.xlsx” for a list of resources used
in the capacity position calculation and their associated dates of operation.
b. Please see the attachment provided in a. above for a list of resources used in the
capacity position calculation and their associated dates of operation. For specifics
regarding Power Purchase Agreement contract end dates, please see pages 27-
29 of Idaho Power’s 2023 Integrated Resource Plan Appendix C.
c. Coal-to-gas conversion assumptions are provided in the table below:
Unit Plant Conversion Status
1 Valmy* Q1 2026 Evaluated during the2023 IRP
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 12
2 Valmy* Q1 2026 Evaluated during the2023 IRP
1 Jim Bridger Q1 2024 Determined during the2021 IRP
2 Jim Bridger Q1 2024 Determined during the2021 IRP
3 Jim Bridger* Q1 2030 Evaluated during the2023 IRP
4 Jim Bridger* Q1 2030 Evaluated during the2023 IRP

* Outside the capacity deficiency analysis; data provided for completeness only
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 13
STAFF REQUEST FOR PRODUCTION NO. 6: Please identify differences in
resources included in this case compared to resources in the last capacity deficiency case
(Case No. IPC-E-21-09) and justify these changes.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 6: The resources listed
in Case No. IPC-E-21-09 used the 2021 Integrated Resource Plan (“IRP”) as the basis
for resources. This case, IPC-E-23-27, uses the 2023 IRP as the basis for the resources.
The resources highlighted in yellow in the attachment provided in the Company’s
response to Request No. 5 represent the differences between IPC-E-21-09 and IPC-E-
23-27. These resources additions were the subject of prior cases IPC-E-22-06, IPC-E-
22-13, IPC-E-22-29, IPC-E-23-05 and IPC-E-23-20 and approved by the Commission.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 14
STAFF REQUEST FOR PRODUCTION NO. 7: Please explain how market
purchase capacity is represented in the R-CAT model and how transmission capacity
affects it. In the answer, please identify any incremental additions of transmission
capacity, the amount of contributed firm capacity to the Company's system, and the timing
of each.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 7: Market
purchases are modeled by the amount of firm capacity available in the transmission
system. Table 7.1 of the 2023 Integrated Resource Plan (“IRP”) shows the transmission
capacity of the transmission paths that affect Idaho Power. The amount of firm capacity
modeled in the Company’s Reliability and Capacity Assessment Tool (“RCAT”) is
described in Table 7.4 of the 2023 IRP.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 15
STAFF REQUEST FOR PRODUCTION NO. 8: Please explain if all firm
transmission capacity included in this case is backed by contracts.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 8: Firm
transmission capacity included in this case is not backed by specific resource contracts.
Table 7.4 of the 2023 Integrated Resource Plan describes the capacity modeling
assumptions used in this case for existing transmission connections. For transmission to
be given a credit toward the annual capacity position, transmission used for imports must
have a corresponding firm third-party transmission reservation between an energy market
hub and the Idaho Power transmission system. Also included in Table 7.4 is Emergency
Transmission or Capacity Benefit Margin (“CBM”). CBM-held capacity on the Idaho Power
system does not have a corresponding third-party reservation beyond the Idaho Power
transmission border.
The planned Boardman to Hemingway (“B2H”) line in 2026 will come with a
corresponding transmission reservation on the Bonneville Power Administration
transmission system between the Mid-C market hub and the Longhorn terminus of B2H.
The Four Corners transmission capacity gained by Idaho Power through the B2H-related
asset exchange with PacifiCorp will provide Idaho Power a direct transmission ownership
path from the Four Corners desert southwest market hub to Idaho Power. Therefore, a
third-party reservation is not necessary for the anticipated Four Corners transmission
capacity.
The response to this Request is sponsored by Curtis Westhoff, System Consulting
Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 16
STAFF REQUEST FOR PRODUCTION NO. 9: Besides Capacity Benefit Margin
("CBM"), please list any other non-firm transmission capacity included in the L&R Balance
and why it is included.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 9: For
clarification, Idaho Power has replaced the traditional Load and Resource Balance with
the annual capacity position analysis (as derived through the Loss of Load Expectation
methodology). There is no other non-firm transmission capacity included in the calculation
of the capacity position other than CBM.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 17
STAFF REQUEST FOR PRODUCTION NO. 10: Please explain the assumptions
regarding PURPA contract renewals and how these assumptions are justified.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 10: The general
IRP modeling assumption regarding PURPA contract renewals is that all qualifying facility
(“QF”) resources, except for wind, enter into replacement contracts when their existing
contracts expire. This assumption is based on Idaho Power’s experience with these
resource types generally entering into replacement contracts when their existing contracts
expire. The baseline IRP modeling assumes that wind QFs do not renew when they
expire; this assumption is based on Idaho Power’s experience and discussions with
developers indicating either a lack of interest in a replacement contract, or uncertainty as
to whether the project would seek a replacement contract or a different contract structure,
or uncertainty as to the project’s plans after the existing contract expires.
The July 2026 first deficit date identified in the Preferred Portfolio of the 2023 IRP
is based on the above assumptions. In the current IRP, Idaho Power ran additional
scenarios including one in which all wind QFs enter into replacement contracts and in
which certain amounts of new QFs are assumed to come online over the planning horizon.
The above assumptions and scenarios were discussed in detail with the IRP Advisory
Council and were discussed in the 2023 IRP, p. 128.
The response to this Request is sponsored by Camille Christen, Resource
Planning, Acquisition, and Coordination Manager, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 18
STAFF REQUEST FOR PRODUCTION NO. 11: Please explain the renewal
assumptions of non-PURPA contracts in this case and how the assumptions are justified.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 11: Non-PURPA
Power Purchase Agreements (“PPA”) are not assumed to enter into new contracts with
Idaho Power when their existing contracts expire. Non-PURPA projects have no right nor
obligation to continue selling to Idaho Power once the existing contract expires. Any new
contract with the project after that time would be based on negotiations regarding pricing,
terms, and conditions at the time and would be subject to Idaho Power’s needs at the
time. The assumption that non-PURPA PPAs do not enter into new contracts with Idaho
Power when their existing contracts expire was discussed with the IRP Advisory Council.
Thus, not including a renewal assumption reflects the actual rights and obligations of the
parties and ensures that Idaho Power appropriately identifies its future needs. If a new
contract was executed with an existing project, that information would be reflected in any
subsequent Request for Proposal evaluations and IRPs.
The response to this Request is sponsored by Camille Christen, Resource
Acquisition, Planning, and Coordination Manager, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 19
STAFF REQUEST FOR PRODUCTION NO. 12: Please identify when Valmy Unit
2 is assumed to close in the R-CAT model.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 12: For the
capacity deficiency analysis, Valmy Unit 2 was assumed to cease operations at the end
of 2025 (December 31st, 2025).
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 20
STAFF REQUEST FOR PRODUCTION NO. 13: Please verify whether Demand
Response uses the following assumptions: (1) existing DR programs are included at the
current levels but can reflect forecasted changes in the amount based on forecast levels
of participation or known changes to programs; and (2) future new DR programs are not
included. If not, please explain what assumptions are used and why they are used.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 13: The Company
uses the existing Demand Response (“DR”) program at the current levels. The Company
does not include forecasted changes in participation level. No new DR programs are
included.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 21
STAFF REQUEST FOR PRODUCTION NO. 14: Please verify whether all cost-
effective Energy Efficiency ("EE") programs are included based on forecasted
participation. If not, please explain the EE assumptions used in the R-CAT model.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 14: Cost-effective
energy efficiency is included as a decrement to the load forecast and is therefore
accounted for in the Company’s Reliability and Capacity Assessment Tool (“RCAT”).
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 22
STAFF REQUEST FOR PRODUCTION NO. 15: Please verify whether on-site
generation uses current levels but can reflect forecasted levels of participation or known
changes. If not, please explain the capacity assumptions of on-site generation in the R-
CAT model.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 15: The
forecasted levels of on-site generation are included in the load forecast and is therefore
accounted for in the Company’s Reliability and Capacity Assessment Tool (“RCAT”).
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 23
STAFF REQUEST FOR PRODUCTION NO. 16: Please explain how B2H is
included in the R-CAT model.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 16: In the
Company’s Reliability and Capacity Assessment Tool (“RCAT”), the Boardman to
Hemingway (“B2H”) transmission line is modeled as a resource, similar to market
purchases, with a monthly capacity value and an Equivalent Forced Outage Rate during
demand (referred to as EFORd).
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 24
STAFF REQUEST FOR PRODUCTION NO. 17: Please explain whether
resources proposed in Case No. IPC-E-23-05 are included in the R-CAT model.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 17: Yes, the
resources proposed in IPC-E-23-05 are included in the Company’s Reliability and
Capacity Assessment Tool (“RCAT”).
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 25
STAFF REQUEST FOR PRODUCTION NO. 18: Please explain whether
resources proposed in Case No. IPC-E-23-20 are included in the R-CAT model.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 18: Yes, the
resources proposed in IPC-E-23-20 are included in the Company’s Reliability and
Capacity Assessment Tool (“RCAT”).
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 26
STAFF REQUEST FOR PRODUCTION NO. 19: Page 92 of Appendix C of the
2023 IRP states the Company includes 14 MW of WRAP capacity benefit beginning in
2027 through the planning horizon. Please answer the following:
a. Does the 14 MW of WRAP capacity contribution occur in 2027 in the L&R balance
in this case?
b. If it is different, please explain why.
c. Can each participant in the WRAP establish when their commitment for binding
will occur? Please explain.
d. Has the Company made a firm commitment when it will become binding? Please
explain.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 19: Please see the
responses below:
a. Yes, the 14 MW of Western Resource Adequacy Program (“WRAP”) capacity was
modeled to begin in 2027.
b. Not applicable.
c. Binding participation in WRAP must commence between the Summer 2025 and
Summer 2028 seasons. Within this window, participants will individually choose
the season to commence binding participation. WRAP established this three-year
binding commitment window in recognition that not all participants may have made
all necessary arrangements and implemented all necessary business processes
at the program’s outset to secure WRAP qualifying resources, meet the various
WRAP obligations, and avoid imposition of non-compliance related charges. The
goal of this window is for participants to be fully prepared for binding participation
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 27
and, therefore, more likely to maintain ongoing participation, helping keep WRAP
viable and providing value to the region through the diversity of loads, resources,
and transmission.
d. Idaho Power has not committed to a binding participation date. The Company
initially targeted Summer 2027 as the first binding season. However, there has
been discussion among WRAP participants to collectively target an earlier binding
date. The greater the number of binding participants, the greater the diversity of
loads, resources, and transmission, and, by extension, the ability to reconcile
deficits and surpluses in the operating time horizon. Idaho Power is assessing the
possibility of commencing binding participation in Summer 2026 but has yet to
finalize a decision. It is expected that binding participation will occur no later than
Summer 2027. The Company will alert the Commission prior to committing to a
binding participation date.
The response to this Request is sponsored by Andrés Valdepeña Delgado, System
Planning Engineer, Idaho Power Company.
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 28
Respectfully submitted this 5th day of December 2023.

MEGAN GOICOECHEA ALLEN
Attorney for Idaho Power Company
IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY - 29
CERTIFICATE OF SERVICE

I HEREBY CERTIFY that on this 5th day of December 2023, I served a true and
correct copy of the within and foregoing IDAHO POWER COMPANY’S RESPONSE TO
THE FIRST 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:

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]

C. Tom Arkoosh
Arkoosh Law Offices
913 W. River Street, Suite 450
P.O. Box 2900
Boise, ID 83701
Hand Delivered
_ U.S. Mail
Overnight Mail
FAX
X Email – [e-mail]
[e-mail]

________________________________
Christy Davenport, Legal Assistant

BEFORE THE

IDAHO PUBLIC UTILITIES COMMISSION

CASE NO. IPC-E-23-27

IDAHO POWER COMPANY

ATTACHMENT 1
Response to Request for Production No. 1

SEE CONFIDENTIAL EXCEL
SPREADSHEET

BEFORE THE

IDAHO PUBLIC UTILITIES COMMISSION

CASE NO. IPC-E-23-27

IDAHO POWER COMPANY

ATTACHMENT 2
Response to Request for Production No. 3

IDAHO POWER COMPANY’S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF- 6
STAFF REQUEST FOR PRODUCTION NO. 4: Please provide the rational for
using 90% of total hourly risk to determine seasons of highest risk.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 4:
The goal in establishing a threshold to determine seasons of highest risk is to
identify the critical timeframes that incentivize either additional resource output or reduced
demand. Utilizing 100 percent of total hourly risk would include all hours of the year and
provide no meaningful information. Meanwhile, utilizing a 90 percent threshold eliminates
the non-critical hours, while still accounting for different weather patterns from the six test
years of historical data when establishing seasons.
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 FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF- 7
STAFF REQUEST FOR PRODUCTION NO. 5: Please define the "time of
occurrence" used to group the top 90% of LOLP values when determining seasons of
highest risk.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 5:
When determining seasons of highest risk, a Loss of Load Probability (“LOLP”) is
calculated for each hour in the calendar year. Then, the top 90 percent of those calculated
hourly LOLP values are selected to inform the seasons of highest risk. Each LOLP value
that is within the top 90 percent maintains its individually associated time stamp, which
includes the hour, day, and month. The associated time stamps of the top 90 percent
LOLP values are the referenced “time of occurrence.” For example, if the highest LOLP
value occurred on July 14th at 7:00 pm, that would be its “time of occurrence.” For
determining the seasons of highest risk, the Company focuses on the day and month of
the top 90 percent of LOLP values and their time of occurrence.
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 FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF- 8
STAFF REQUEST FOR PRODUCTION NO. 6: Please define the criteria that the
Company uses to identify the seasons of highest risk as November 1 through February
28 and June 1 through September 15.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 6:
As discussed in the Company’s responses to Request Nos. 4 and 5, the Company
first calculated the top 90 percent of Loss of Load Probabilities (“LOLP”) and their
associated times of occurrence. Then, utilizing the identified times of occurrences, the
time stamps were grouped by month. Within each month, the time stamps were then
grouped by the nearest half month. For example, if the latest identified time stamp in
September occurred on the 9th, the season was extended to September 15th to account
for the year-to-year variation in weather and load.
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 FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF- 9
STAFF REQUEST FOR PRODUCTION NO. 7: Please provide the rationale for
selecting the top 50% risk hours in each month for the purpose of determining the hours
of highest risk.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 7:
The top 50 percent of risk hours per month threshold was selected to create a
relevant and manageable sample size for determining the hours of highest risk. For
example, this threshold reduces the 720 hours in the month of June to a number in the
double digits. This sample includes enough data points to develop a meaningful
distribution of high-risk hours and captures the year-to-year and day-to-day variability of
the calculated Loss of Load Probabilities (“LOLP”), while also minimizing computational
burden.
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 FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF- 10
STAFF REQUEST FOR PRODUCTION NO. 8: Please describe the "percent of
occurrence threshold" that the Company uses to differentiate between hours of medium
risk and hours of highest risk.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 8:
Using the top 50 percent of risk hours, as described in the Company’s response to
Request No. 7, the Company identified monthly risk hours by grouping data points by the
hour of day in which they occurred. Then, from the determined monthly risk hours, the
highest risk hours were identified from the percent of occurrences greater than
approximately 15 percent for the summer months and the percent of occurrences greater
than approximately 10 percent for the winter months. Hours that did not exceed these
thresholds were determined to be “medium risk” hours.
The response to this Request is sponsored by Jared Ellsworth, Transmission,
Distribution & Resource Planning Director, Idaho Power Company.

BEFORE THE

IDAHO PUBLIC UTILITIES COMMISSION

CASE NO. IPC-E-23-27

IDAHO POWER COMPANY

ATTACHMENT 3
Response to Request for Production No. 5

SEE EXCEL SPREADSHEET