20250227IPC to Staff 1-11 - Redacted.pdf

-NIQAW POWER,
DONOVAN WALKER
Lead Counsel
dwal ker(@j da h o power.corn
RECEIVED
February 27, 2025 February 27, 2025
IDAHO PUBLIC
UTILITIES COMMISSION
VIA ELECTRONIC FILING
Commission 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-24-45
Application of Idaho Power Company for a Certificate of Public
Convenience and Necessity for Two Battery Storage Facilities
Dear Commission Secretary:
Attached for electronic filing is Idaho Power Company's ("Idaho Power") Response
to the First Production Request of the Commission Staff to Idaho Power in the above-
referenced matter.
The response and attachments contain confidential information and will be
provided to the parties who sign the Protective Agreement.
If you have any questions about any of the aforementioned documents, please do
not hesitate to contact me.
Very truly yours,
I�W� -�.za4
Donovan E. Walker
DEW:sg
Enclosures
1221 W. Idaho St(83702)
P.O. Box 70
Boise, ID 83707

CERTIFICATE OF ATTORNEY
ASSERTION THAT INFORMATION CONTAINED IN AN IDAHO PUBLIC UTILITIES
COMMISSION FILING IS PROTECTED FROM PUBLIC INSPECTION
Case No. IPC-E-24-45
Idaho Power Company's Application for a Certificate of Public Convenience and
Necessity for Two Battery Storage Facilities
The undersigned attorney, in accordance with Commission Rules of Procedure 67,
believes that Idaho Power Company's Response to the First Production Request of the
Commission Staff and all of the attachments dated February 27, 2025, contain information
that Idaho Power Company and a third party claim are trade secrets, business records of
a private enterprise required by law to be submitted to or inspected by a public agency,
and/or public records exempt from disclosure by state or federal law (material nonpublic
information under U.S. Securities and Exchange Commission Regulation FD) 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 27' day of February, 2025.
Donovan E. Walker
Counsel for Idaho Power Company

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]
dwalker(o-)idahopower.com
Attorney for Idaho Power Company
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF IDAHO POWER )
COMPANY'S APPLICATION FOR A ) CASE NO. IPC-E-24-45
CERTIFICATE OF PUBLIC CONVENIENCE )
AND NECESSITY FOR TWO BATTERY ) IDAHO POWER COMPANY'S
STORAGE FACILITIES. ) RESPONSE TO THE FIRST
PRODUCTION REQUEST OF
THE COMMISSION STAFF
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 February 6, 2025, herewith submits the following information:
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 1

REQUEST FOR PRODUCTION NO. 1: Company Witness Ellsworth stated the
Company updated its AURORA modeling inputs to include a wildfire risk factor. Ellsworth
Direct at 11. Please provide supporting workpapers that demonstrates how the wildfire
risk factor was calculated. Additionally, please explain how the wildfire risk factor
impacted the model.
RESPONSE TO REQUEST FOR PRODUCTION NO. 1: Please note, the
modeling input updates referenced in Mr. Ellsworth's Direct Testimony at 11 is referencing
an update to an input of the Company's Reliability and Capacity Assessment Tool
("RCAT"). The RCAT model produces annual capacity positions which can be utilized to
develop Planning Reserve Margin ("PRM") values and Effective Load Carrying Capability
("ELCC") values; PRM values and ELCC values are then fed as inputs into the AURORA
model during calibration efforts. In summary, the wildfire risk factors are modeled in the
Company's RCAT model, which impacts the RCAT-produced values that are input into
the AURORA model.
Please see the Response to Staff's Request No. 1 — Confidential Attachment for
the workpapers that support the wildfire risk factor calculation. First, the system operator
logs were obtained for all transmission outages caused by wildfire-related events, as
shown on the Operator Log tab. While all the transmission outages listed impacted Idaho
Power's system from an operational perspective, the AURORA and RCAT models do not
consider the Company's internal transmission system, therefore internal transmission
outages were not considered when developing the wildfire risk factors. Instead, the
analysis specifically focuses on the lines that are utilized to bring generation into Idaho
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 2

Power's Balancing Authority ("BA"). The following defines each of the considered region
categories:
1. Internal Transmission — Represents all transmission outages that are internal to Idaho
Power's system; these outages were not considered in the wildfire risk factor
calculations.
2. Idaho Northwest— Represents the 230-kV system connection to the Pacific Northwest.
3. Summer Lake — Represents the 500-kV system connection to the Pacific Northwest.
4. East Transmission — Represents the transmission system on the east of Idaho Power
which is utilized to move the generation from the Jim Bridger power plant ("Bridger")
to the Company's BA.
Data for the transmission outages due to wildfire-related events was then
categorized by year of occurrence, as shown in the tabs labeled 2022, 2023 and 2024.
For each year, the number of days where an outage occurred for each of the categories
was identified. These outages were then converted to a percentage of days over the
summer to represent the likelihood of Idaho Power experiencing an outage due to wildfire-
related events.
On the Summary tab, the Equivalent Forced Outage Rate during Demand
("EFORd") column shows the average percentage of days over the summer across 2022
through 2024. The wildfire risk for the east transmission was modeled by increasing the
EFORd of the Bridger units by the east transmission EFORd during the identified summer
months in the RCAT model.
The wildfire risk for Idaho Northwest and Summer Lake was modeled using their
corresponding calculated EFORd values and negative capacity during the summer
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 3

months. The negative capacity reflects the impact of losing those two elements, which
was calculated by identifying the decrease in Total Transfer Capability ("TTC") of the
corresponding Path 14 (Idaho Northwest) and Path 75 (Summer Lake) and the stranded
generation potential (i.e., Hells Canyon Power Plant). The impact on the TTC and
stranded generation was then offset by the Capacity Benefit Margin and the Transmission
Reliability Margin that Idaho Power holds in the Idaho Northwest path.
Incorporating these wildfire risk inputs into the RCAT model impacts the outage
generation table used to calculate the Loss of Load Expectation ("LOLE"), thus impacting
the annual capacity position calculation.
The response to this Request is sponsored by Andres Valdepena Delgado, System
Consulting Engineer, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF -4

REQUEST FOR PRODUCTION NO. 2: For each of the 50 MW Battery Energy
Storage System ("BESS") projects, please explain the following:
a. Please explain whether the additional 50 MW will be on the same site, adjacent
site, or non-contiguous to the original project. In the response, please provide a
geospatial PDF map;
b. Please explain the method of electrical integration to the original project; and
c. Please provide the estimated operation and maintenance ("O&W) costs and
explain how it was factored into the project's cost-effectiveness.
RESPONSE TO REQUEST FOR PRODUCTION NO. 2:
a. Hemingway Incremental 50 MW BESS The Hemingway Incremental 50 MW BESS
will be located at the Idaho Power Hemingway Station in Owyhee County and is
encompassed within the same station boundary as the 80 MW Hemingway BESS
and 36 MW Hemingway Expansion BESS for which the Commission issued a
Certificate of Public Convenience and Necessity ("CPCN"). The project will
connect through the same point of interconnection. See Response to Staff's
Request No. 2 — Confidential Attachment 1 for a reference drawing of the project.
Boise Bench 50 MW Expansion BESS The Boise Bench 50 MW Expansion BESS
will be located at the Boise Bench Station in Ada County and is directly
incorporated into the 150 MW Boise Bench BESS for which the Commission
issued a CPCN. The project will connect through the same point of interconnection.
See Response to Staff's Request No. 2 —Confidential Attachment 2 for a reference
drawing of the project.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 5

b. Hemingway Incremental 50 MW BESS The BESS will be electrically connected to
the same point of interconnection as the existing battery assets. Although the
manufacturer is disparate, the entirety of the Hemingway BESS facilities, including
the total 166 MW of battery storage, are designed to operate as a single
operational asset. Each system can function independently but will sum and
discharge generally coincidentally through the point of interconnection.
Boise Bench 50 MW Expansion BESS The BESS will be incorporated into a single
200 MW BESS facility and fully integrated as a single operational asset connected
through a single point of interconnection.
c. The O&M costs evaluated considered long-term service agreements, warranties,
and augmentation, as well as property taxes and property insurance, which are all
a component of the calculation of the levelized cost of a BESS.
Hemingway Incremental 50 MW BESS First year O&M for the Hemingway
Incremental 50 MW BESS was estimated to be $1.5 million increasing to $2.0
million over the remaining life of the project.
Boise Bench 50 MW Expansion BESS First year O&M for the additional Boise
Bench 50 MW Expansion is estimated to be $1.4 million increasing to $1.9 million
over the remaining life of the project.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 6

REQUEST FOR PRODUCTION NO. 3: Please provide an updated total cost
estimate for the development and construction of the Boise Bench 50 MW Expansion
BESS project, similar to the table contained in Response to Production Request No. 4 in
Case IPC-E-24-16. In the table, please include an updated cost estimate for the total 200
MW Boise Bench BESS project.
RESPONSE TO REQUEST FOR PRODUCTION NO. 3: The following table
includes the current cost estimate for both the Boise Bench 50 MW Expansion BESS as
well as the full 200 MW Boise Bench BESS project. Due to favorable BESS supply terms,
the Company was able to procure the entire 200 MW BESS system for only approximately
more than the 150 MW BESS system identified in Case No. IPC-E-24-16.
IPC-E-24-16 50 MW 200 MW
150 MW
Manufacturer Supplied BESS Equipment
Project Management, Engineering, Design,
Construction Management, Permitting, and
General Administration
Civil Construction, Site Work, Underground
Conduit and Grounding, Fencing, Concrete
Foundations
Electrical Construction
BESS Installation
Testing and Commissioning
Idaho Power Interconnection Facilities -
TOTAL
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 7

REQUEST FOR PRODUCTION NO. 4: Please provide an updated total cost
estimate for the development and construction of the Hemingway Incremental 50 MW
BESS project, similar to the table contained in Response to Production Request No. 4 in
Case IPC-E-24-16.
RESPONSE TO REQUEST FOR PRODUCTION NO. 4: The following table
includes the current cost estimate for Hemingway Incremental 50 MW BESS project.
Manufacturer Supplied BESS Equipment
Project Management, Engineering, Design, '
Construction Management, Permitting, and General
Administration
Civil Construction, Site Work, Underground Conduit
and Grounding, Fencing, Concrete Foundations
Electrical Construction
BESS Installation
Testing and Commissioning
Idaho Power Interconnection Facilities
TOTAL
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 8

REQUEST FOR PRODUCTION NO. 5: The Company's two projects are the Boise
Bench 50 MW Expansion and the Hemingway Incremental 50 MW. Please explain what
the difference is between the terms "Expansion" and "Incremental".
RESPONSE TO REQUEST FOR PRODUCTION NO. 5: There is no substantive
intent connected to the naming convention. The Boise Bench 50 MW Expansion was
related to an increased size to an executed supply agreement and thus was an expansion
of the original 150 MW Boise Bench BESS to be designed and constructed as a single
200 MW facility. The Hemingway Incremental 50 MW was stated as such to discern the
project from the existing Hemingway 80 MW and Hemingway 36 MW BESS projects.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 9

REQUEST FOR PRODUCTION NO. 6: In IPC-E-24-16, Hackett's testimony
referred to a Long-Term Services Agreement for O&M services performed for the energy
storage project following commercial operation of the project. IPC-E-24-16 Hackett at 47.
Please explain if the Agreement has been updated to include the Boise Bench 50 MW
Expansion BESS. Additionally, please answer the following:
a. If the Company has an executed Long-Term Services Agreement, please provide
the Agreement; and
b. Please provide the updated cost of the Long-Term Services Agreement.
RESPONSE TO REQUEST FOR PRODUCTION NO. 6:
a. The Company is actively negotiating a Long-Term Services Agreement ("LTSA")
but has not yet executed an LTSA for either the original 150 MW Boise Bench
BESS or the Boise Bench 50 MW Expansion BESS. The effort to negotiate and
execute an LTSA will be inclusive of the entire 200 MW facility.
b. Updated costs are not available as the Company is evaluating the scope of
services and the applicable associated costs, the ability to conduct operation and
maintenance services with existing resources, and the specific terms and
conditions to facilitate a favorable agreement.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 10

REQUEST FOR PRODUCTION NO. 7: Please answer the following questions
regarding the Boise Bench 50 MW Expansion project:
a. Please explain if the project includes any amount of overbuild capacity. If so please
specify the capacity amount, associated cost, and estimated degradation offset;
b. Please describe the expected annual battery degradation of the project and
provide any documentation supporting the estimate;
c. Please explain if the Company has any assumptions for augmentation of the
capacity of this project;
d. Please provide a table of the expected capacity contribution in MW for the Boise
Bench 50 MW expansion for each year across the life of the batteries and include
any planned augmentations; and
e. Please provide a list of milestones that must be met before the project can begin
commercial operation.
RESPONSE TO REQUEST FOR PRODUCTION NO. 7:
a. The Boise Bench 50 MW Expansion is intrinsic in the 200 MW supply agreement,
included as Exhibit No. 4 to Mr. Hackett's testimony, but can be interpolated to
estimate the contribution from the 50 MW component. The guaranteed alternating
current ("AC") usable energy at the point of interconnection of the entire Boise
Bench facility is guaranteed to contribute a minimum of 800 megawatt-hours
("MWh") of nameplate energy through year three, which can be interpolated to
guarantee that the 50 MW Expansion will deliver 200 MWhs over the same
timeframe. To guarantee this nameplate performance, the supply agreement has
a beginning of life expected energy of 886.78 MWh, of which approximately 221.7
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 11

MWh would be associated with the Boise Bench 50 MW Expansion. The BESS is
a four-hour duration system and requires slightly more capacity at the beginning
of life to ensure nameplate ratings after commercial operation for a period of time.
The performance guarantee is a negotiated contractual term within the
construct of the supply agreement and does not have an explicit value, rather it
provides minimum performance assurances based on the overall value of the
contract. Capacity and energy additions are not linear as related to the overall
project cost due to energy losses, some economies of scale in purchase quantities,
balance of plant materials and construction, and ancillary equipment. However, it
is a reasonable proxy for the cost of the beginning of life capacity and contributes
approximately ten percent to the battery supply agreement cost, or approximately
�. It should be noted that energy and capacity guarantees are not offered
by suppliers unless some additional amount of beginning of life capacity is
purchased in the supply agreement. A three-year guarantee is a reasonable
amount of time to ensure performance guarantees are measured.
b. The Boise Bench 50 MW Expansion is expected to degrade at approximately three
percent in the first year and less than two percent in each year following. The
following table, as shown in Exhibit No. 41, presents the expected energy over the
20-year life of the 200 MW BESS:
Exhibit V.1 —Performance,of the Amended&Restated Battery Energy Storage System Supply Agreement included as Exhibit No.
4 to Mr. Hackett's testimony.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 12

Expected Energy net of
Reference Aux Energy as
Period measured at high side
(end of) of HVT
Commissioning Completion 886.78
Year 1 860.65
Year 2 843.85
Year 829.03
Year 4 815.30
Year 5 802.25
Year 789.69
Year 7 777.68
Year 8 765.85
Year 9 754.43
Year 10 743.24
Year 11 732.27
Year 12 721.40
Year 13 710.94
Year 14 700.33
Year 15 690.04
Year 16 679.81
Year 17 669.71
Year 18 659.70
Year 19 649.87
Year 20 640.05
c. Aside from the beginning of life energy discussed in part(a), there are no additional
augmentation assumptions associated with the 50 MW Boise Bench Expansion.
Rather, degradation information is used for planning purposes only as actual
degradation depends not only on the asset life, but the usage. The Company will
make future augmentation decisions after evaluating operational performance to
ensure appropriate investments are made to meet the load service obligations.
Idaho Power has no specific plans or timelines, nor any obligation to the supplier
to augment the facility and will make a prudence determination prior to further
investment.
Please note, though not applicable to the 50 MW Boise Bench Expansion,
for RFP evaluation purposes, Idaho Power does apply equivalent augmentation
decisions to all bids that include a BESS component, therefore a portion of the
levelized cost of BESS projects includes estimated augmentation costs over the
life of the battery storage bid.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 13

d. See the response to part (b) for a table presenting the expected capacity
contribution of the 200 MW Boise Bench BESS and the response to part (c) for a
discussion about planned augmentation.
e. The following table includes the key milestones that must be met prior to
commercial operation:
Milestone Estimated Date
BESS Supplier Drawing Submittal November 2024
Construction Start June 2025
Delivery Complete October 2025
Backfeed Power Available December 2025
Installation Complete December 2025
Commissioning Complete May 2026
Final Completion— Commercial Operation June 2026
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 14

REQUEST FOR PRODUCTION NO. 8: Please answer the following questions
regarding the Hemingway Incremental 50 MW project:
a. Please explain if the project includes any amount of overbuild capacity. If so please
specify the capacity amount, associated cost, and estimated degradation offset;
b. Please describe the expected annual battery degradation of the project and
provide any supporting documentation;
c. Please explain if the Company has any assumptions for augmentation of the
capacity of this project;
d. Please provide a table of the expected capacity contribution in MW for the project
for each year across the life of the batteries and include any planned
augmentations; and
e. Please provide a list of milestones that must be met before the project can begin
commercial operation.
RESPONSE TO REQUEST FOR PRODUCTION NO. 8:
a. The guaranteed AC energy at the point of measurement (medium voltage AC
system) of the facility is guaranteed to be a minimum of 226.185 MWh, as
described in Exhibit C-6 to the System Sale and Purchase Agreement between the
Company and Tesla, Inc. included as Confidential Exhibit No. 5 to Mr. Hackett's
testimony. To guarantee this performance, the supply agreement has a beginning
of life expected energy of 233.520 MWh. The BESS is a four-hour duration system
and requires slightly more capacity at the beginning of life to ensure nameplate
ratings after commercial operation for a period of time.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 15

The performance guarantee is a negotiated contractual term within the
construct of the supply agreement and does not have an explicit value, rather it
provides minimum performance assurances based on the overall value of the
contract. Capacity and energy additions are not linear as related to the overall
project cost due to energy losses, some economies of scale in purchase quantities,
balance of plant materials and construction, and ancillary equipment. However, it
is a reasonable proxy for the cost of the beginning of life capacity and contributes
approximately thirteen percent to the battery supply agreement cost, or
approximately It should be noted that energy and capacity guarantees
are not offered by suppliers unless some amount of additional beginning of life
capacity is purchased in the supply agreement.
b. The Hemingway Incremental 50 MW BESS is expected to degrade at
approximately six percent in the first year and approximately two percent in each
year following. The guaranteed energy retention percentage provides that more
than 200 MWhs will be available through year three. A three-year guarantee is a
reasonable amount of time to ensure performance guarantees are measured. The
following table represents the expected energy over the 20-year life of the BESS:
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 16

Year
Guaranteed Energy Retention Guaranteed Energy Retention
Percentage at POM at POM(MWII)
1 94.00% 212.61
2 91.50% 206.96
3 89.50% 202.44
4 87.50% 197.91
5 86.00% 194.52
6 84.50% 191.13
7 1 83.00% 187.73
8 82.00% 185.47
9 80.50% 182.08
10 79.50% 179.82
11 78.50% 177.56
12 77.00% 174.16
13 75.50% 170.77
14 1 74.00% 167.38
15 72.00% 162.85
16 70.50% 159.46
17 69.00% 156.07
18 67.50% 152.67
19 66.00% 149.28
20 65.00% 147.02
c. Aside from the beginning of life energy discussed in part(a), there are no additional
augmentation assumptions associated with the Hemingway Incremental 50 MW
BESS. Please see the Company's Response to Request No. 7(c) for an
explanation of how BESS degradation information is used, and future
augmentation decisions are made.
d. See part (b) for a table presenting the expected capacity contribution of the
Hemingway Incremental 50 MW BESS.
e. The following table includes the key milestones that must be met prior to
commercial operation:
Milestone Estimated Date
Construction Start June 2025
Site Drawing Approval August 2025
Delivery Complete December 2025
Energization January 2026
Installation Complete February 2026
Commissioning Complete May 2026
Final Completion— Commercial Operation June 2026
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 17

The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Property Accounting Manager, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 18

REQUEST FOR PRODUCTION NO. 9: Figure No. 22 in Exhibit No. 3 of Hackett's
testimony represents the initial shortlist bids for the 2026 commercial online date. Please
respond to the following:
a. Please explain whether these initial shortlist projects were considered to replace
Savion's projects;
b. If yes, for each project in Figure No. 22, please explain why they were not selected,
and provide any analysis and/or documentation (i.e. cost comparison, and project
limits) showing why they were not selected when compared to the two battery
storage projects included in the Company's proposal; and
c. If not, please explain why these initial shortlisted projects were not reviewed or
considered.
RESPONSE TO REQUEST FOR PRODUCTION NO. 9:
a. Idaho Power did consider whether the initial shortlist projects would be able to
meet the remaining 2026 capacity deficit following Savion's inability to obtain the
required permitting. However, of the initial shortlist projects presented in Figure 22,
only three projects still remain viable, but none had the ability to meet the June 1,
2026, commercial operation date. The remaining initial shortlist projects had either
interconnection or permitting cost and timeline issues including unknown
assumptions, did not have available transmission capacity, or did not have the
ability to meet the 2026 timeline. Please see the Response to Staff's Request No.
9 — Confidential Attachment for the projects in Figure 22 with a description of the
current status on feasibility. With a Ievelized cost equivalent to the Ievelized cost
of a final short list project, and a Ievelized cost lowerthan the final short list projects
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 19

and others on the initial short list, the Boise Bench 50 MW expansion and the
Hemingway Incremental 50 MW, respectively, were the least-cost, least-risk
resources necessary to meet the 2026 capacity deficiency.
b. See part (a).
c. Not applicable.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 20

REQUEST FOR PRODUCTION NO. 10: Table No. 2 in Hackett's testimony shows
ten projects that were selected in the AURORA Modeling Scenarios and considered to
move to the final shortlist. For each of the four projects that were not included in the final
short list, please explain why they were not considered as an alternative to replace
Savion's two projects. Please provide any documentation supporting the Company's
reasons.
RESPONSE TO REQUEST FOR PRODUCTION NO. 10: As described in Mr.
Hackett's testimony, the four projects were not included on the final shortlist due to the
uncertainty related to interconnection. Pursuant to Federal Energy Regulatory
Commission Order 2023, issued on November 6, 2023, these four projects were included
in the transition cluster study process that Idaho Power was required to implement for all
early-stage generation projects in the interconnection queue. The transition cluster is a
360-day study that started on January 1, 2024. Because Idaho Power did not anticipate
having results—including interconnection network upgrade costs—until the end of the
fourth quarter of 2024, it could not be evaluated at the time. The Company did not include
these projects in the final shortlist analysis due to the uncertainty of the upgrade and
interconnection costs. A significant change would impact the financial viability of the
proposed project and potentially commercial operation date. Currently, the transition
cluster study process has still not been completed, further supporting the removal of the
four projects from the final shortlist.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 21

REQUEST FOR PRODUCTION NO. 11: Please explain the feasibility of additional
market purchases as an alternative to replace the capacity of Savion's projects.
RESPONSE TO REQUEST FOR PRODUCTION NO. 11: Idaho Power considered
all available options to fill its remaining capacity deficits for 2026 as the challenges
regarding timing and feasibility of the remaining available projects became known. The
Company had previously executed an agreement with a market purchase bid from the
2026 RFP, approved by the Commission with Order No. 36309 in Case No. IPC-E-24-12.
There was no other market bid options from the 2026 RFP to consider. As described in
Mr. Ellsworth's testimony, Idaho Power also executed an agreement for the summer
months of 2026 for a market purchase to be delivered to the Company's border. Additional
market purchase options that effectively address capacity deficits are limited in
availability, as discussed further below, and were not available in amounts sufficient to fill
the capacity deficits created by the infeasibility of the Savion project. Further, the 50 MW
Hemingway Incremental and 50 MW Boise Bench BESS resources will provide longer-
term benefits to the system and Idaho Power customers as they contribute toward what
would otherwise be larger deficits in subsequent years. The BESS are flexible and
dispatchable providing benefits over the life of the asset.
To fill capacity deficits, resources or market purchases must provide incremental
capacity to the system — i.e., either provide new capacity directly to the system, or be
imported on transmission that has not already been assumed to be contributing to the
system. The Company's Integrated Resource Plan and RFP modeling assumes Idaho
Power's existing third-party transmission rights are importing wholesale market energy
purchases and contributing capacity to the system. Therefore, to be considered
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 22

incremental capacity, any new market purchase must be either (1) imported on
incremental transmission rights not already assumed, or (2) delivered directly to the
system at the Company's border.
The regional transmission system around and including Idaho Power's system has
been constrained over the past several years. Until new transmission is built, it is unlikely
that additional long-term firm transmission capacity, beyond what Idaho Power has
already reserved, will become available in any significant volumes. Transmission can
become available on occasion, and when it does, Idaho Power evaluates purchasing it.
To date, no other long-term firm transmission has been made available in volumes
sufficient to address the remaining 2026 deficits.
The second option, energy purchases that the seller can deliver to Idaho Power's
border, are also extremely limited and transmission-dependent. There are few
counterparties that have both (1) willingness to commit surplus generation capacity to a
sale a year or more in advance and (2) firm transmission to deliver the generation to the
Company's border at a point where Idaho Power also has internal firm transmission with
which to deliver the purchase to load. As discussed above, Idaho Power identified one
counterparty with surplus generation willing to commit to a sale that has transmission to
deliver to Idaho Power's border, and entered into a 50 MW firm energy purchase for the
months of June 2026 through August 2026, around the clock, seven days a week with
this counterparty. As this purchase is delivered to the Company's border, it is considered
incremental capacity and reduced the 2026 capacity deficit but does not have an effect
on future years' deficits. Idaho Power has not identified additional counterparties with the
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 23

ability and willingness to make a similar energy sale and firm delivery to its border and
ultimately to load for 2026.
The response to this Request is sponsored by Camille Christen, Resource
Acquisition, Planning, and Coordination Manager, Idaho Power Company.
DATED at Boise, Idaho this 27t" day of February 2025.
DONOVAN E. WALKER
Attorney for Idaho Power Company
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 24

CERTIFICATE OF SERVICE
I HEREBY CERTIFY that on this 27th day of February 2025, 1 served a true and
correct copy of foregoing Idaho Power Company's Response to the First Production
Request of the Commission Staff upon the following named parties by the method
indicated below, and addressed to the following:
Commission Staff Hand Delivered
Adam Triplett U.S. Mail
Deputy Attorney General Overnight Mail
Idaho Public Utilities Commission FAX
11331 W. Chinden Blvd., Bldg No. 8 FTP Site
Suite 201-A (83714) X Email Adam.Triplett(a puc.idaho.gov
PO Box 83720
Boise, ID 83720-0074
Industrial Customers of Idaho Power Hand Delivered
c/o Peter J. Richardson U.S. Mail
Richardson Adams, PLLC Overnight Mail
515 N. 27' Street FAX
Boise, Idaho 83702 FTP Site
X Email peter(a)richardsonadams.com
Dr. Don Reading Hand Delivered
280 S. Silverwood Way U.S. Mail
Eagle, Idaho 83716 Overnight Mail
FAX
FTP Site
X Email dreading(a mindspring.com
Idaho Irrigation Pumpers Association, Hand Delivered
Inc. U.S. Mail
Eric L. Olsen Overnight Mail
Echo Hawk & Olsen, PLLC FAX
505 Pershing Ave., Ste. 100 FTP Site
P.O. Box 6119 X Email elo _echohawk.com
Pocatello, Idaho 83205
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 25

Lance Kaufman, Ph.D. Hand Delivered
2623 NW Bluebell Place U.S. Mail
Corvallis, OR 97330 Overnight Mail
FAX
FTP Site
X Email lance(a)aegisinsight.com
Micron Technology, Inc. Hand Delivered
Austin Rueschhoff U.S. Mail
Thorvald A. Nelson Overnight Mail
Austin W. Jensen FAX
Kristine A.K. Roach FTP Site
Holland & Hart LLP X Email
555 17' Street, Suite 3200 darueschhoff(a)hol land hart.com
Denver, CO 80202 tnelson hol land hart.com
awiensen(a)hol land hart.com
karoach hollandhart.com
aclee(a)hol land ha rt.com
Stacy Gust
Regulatory Administrative Assistant
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF - 26