20240529IPC to Staff 1-10 (Redacted).pdf

0IQAW POWER.
DONOVAN WALKER
Lead Counsel RECEIVED
dwalker(@idahopower.com Wednesday, May 29, 2024
IDAHO PUBLIC
UTILITIES COMMISSION
May 29, 2024
VIA ELECTRONIC FILING
Monica Barrios-Sanchez, 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-24-16
In the Matter of Idaho Power Company's Application for a Certificate of
Public Convenience and Necessity for the Boise Bench Battery Storage
Facility
Dear Barrios-Sanchez:
Attached for electronic filing please find Idaho Power Company's Response to the
First Production Request of the Commission Staff in the above matter.
The confidential documents will be sent separately to the parties who sign the
Protective Agreement in a separate encrypted email.
Please feel free to contact me directly with any questions you might have about
this filing.
Very truly yours,
- S�0e,
Donovan E. Walker
DEW:sg
Attachments

CERTIFICATE OF ATTORNEY
ASSERTION THAT INFORMATION CONTAINED IN AN IDAHO PUBLIC UTILITIES
COMMISSION FILING IS PROTECTED FROM PUBLIC INSPECTION
Application for a Certificate of Public Convenience and Necessity for the Boise
Bench Battery Storage Facility
IPC-E-24-16
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 to Idaho Power Company and Attachments, contain information that
Idaho Power Company and a third party claims are confidential trade secret as described
in Idaho Code § 74-101, et seq., and/or § 48-801, et seq. As such, they are protected
from public disclosure and exempt from public inspection, examination, or copying.
DATED this 29' day of May 2024.
Donovan 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(a-)_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-24-16
CERTIFICATE OF PUBLIC CONVENIENCE )
AND NECESSITY FOR THE BOISE ) IDAHO POWER COMPANY'S
BENCH BATTERY STORAGE FACILITY. ) REDACTED 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 May 8, 2024, herewith submits the following information:

REQUEST FOR PRODUCTION NO. 1: Please provide the Company's final
proposal of the Boise Bench Battery Energy Storage System ("BESS") for the 2026 RFP.
Please include a description of construction or expansion, a map of the project,
construction timelines, cost estimates, and impact on revenue requirements. Please
answer the following:
a. Please explain when the Company obtained the final cost estimate for the BESS
project;
b. Did the Company include inflation in the final cost estimate? If so, please provide
the escalation factor which was used;
c. Please provide the final configuration and pricing of the BESS project that the
Company used for the AURORA modeling assessment; and
d. Please explain if the Company's proposal is based on a specific battery supplier.
If so, please explain who the battery supplier will be.
RESPONSE TO REQUEST FOR PRODUCTION NO. 1: Please see Response to
Staff's Request No. 1 — Confidential Attachments 1 through 9 for the Boise Bench BESS
final proposal submitted as part of the 2026 RFP. Construction at the Boise Bench
substation is anticipated to begin in the spring of 2025, and will involve general site
grading and preparation, foundation construction, grounding, and conduit installation
followed by battery installation in winter 2025/2026. After installation, testing and
commissioning will be completed prior to commercial operation expected by June 1, 2026.
a. For the final short-list evaluation, the Boise Bench BESS project cost was updated
with all other bids in August of 2023 after the initial short-list was determined.

b. Yes. Inflation was built into the Boise Bench BESS bid that was updated in August
2023. Please see page 1 of Request No. 1 — Confidential Attachment 8 for the
escalation factor utilized in the updated bid.
c. Please see Response to Request No. 1 — Confidential Attachment 6 for the
conceptual layout of the bid as proposed. The total capital cost provided in August
2023 and used for modeling in AURORA was , and the levelized
cost, which includes capital costs, depreciation expense, tax expense, financing
costs, fixed operations and maintenance expenses, and property taxes and
insurance, was_/kilowatt ("kW")-month.
d. The bid was not based on a specific battery supplier. As described in the Direct
Testimony of Eric Hackett, upon notification of selection by the Idaho Power
Evaluation Team following approval of the final shortlist by the Oregon Public Utility
Commission, the Company's Power Supply department began discussions with
suppliers for procurement of the BESS but had not yet executed a purchase order.
The response to this Request is sponsored by Eric Hackett, Projects and
Resource Development Director, Idaho Power Company.

REQUEST FOR PRODUCTION NO. 2: Please answer the following regarding
battery degradation:
a. Please explain what the expected annual battery degradation of the Boise Bench
BESS project is and provide any supporting documentation;
b. Please provide a table of the expected capacity contribution in MW for the Boise
Bench BESS for each year across the life of the batteries; and
c. Please explain if the Company will overbuild the Boise Bench BESS to maintain
150 MW of operating capacity.
i. If so, please explain by how much the Company will overbuild and the cost
estimate; and
ii. If so, please explain if the cost of overbuilding was included in the
Company's total cost estimate in its final proposal for the 2026 RFP.
RESPONSE TO REQUEST FOR PRODUCTION NO. 2:
a. The expected annual degradation is assumed to be approximately six to seven
percent in the first year and two to three percent in future years. See Table 6-1:
AC expected capacity of initial battery system (without augmentation) in the
Response to Staff's Request No. 2 — Confidential Attachment for the source of
Idaho Power's expected annual degradation factors.
b. The expected capacity contribution for the Boise Bench BESS is anticipated to
remain at the 150 MW nameplate capacity throughout the life of the batteries. As
discussed below, to do so, augmentation may be required in the future as the
BESS degrades below the nameplate capacity. The Company expects to make
augmentation decisions based on then-current capacity contributions of the Boise

Bench BESS as it relates to future degradation and system capacity needs. Note
for the bid evaluation process, the Evaluation Team added to all BESS proposals,
annual costs throughout the life of the BESS to account for the cost of keeping the
BESS at its original nameplate capacity.
c. In the 2026 RFP, the Company requested all asset purchases for BESS projects
to include a 2 year overbuild to ensure capacity is maintained at least through the
first two years of operation. The cost of overbuilding was included in the Boise
Bench BESS bid's total cost estimate of and evaluated in the RFP
process. As all bids were requested to include exactly a 2-year overbuild, no
adjustment between bids of differing overbuilds was necessary. Note, the overbuild
will provide additional megawatt-hours ("MWh") at day one of the project, providing
more than 4 hours of duration.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.

REQUEST FOR PRODUCTION NO. 3: Please provide estimates for the round-
trip efficiency across the life of the system along with supporting documentation.
Additionally, please explain how the Company is modeling and factoring in round-trip
efficiency for the Boise Bench BESS.
RESPONSE TO REQUEST FOR PRODUCTION NO. 3: The Company
models/factors in the round-trip efficiency for BESS projects in AURORA through a round
trip efficiency input. AURORA uses this input to calculate how much energy is needed to
charge the battery. For example, AURORA would see an 85 percent round-trip efficiency
as an input for a 150 MW 4-hr BESS project (600 MWh) and would in turn need to use
--706 MWh of energy to fully charge the BESS (600 MWh / 85 percent). Consistent with
modeling of the round-trip efficiency in the 2023 IRP, Idaho Power modeled all BESS
projects as part of the RFP bid evaluation with a consistent 85 percent round trip efficiency
assumption. Because the Company has not executed a purchase order for the Boise
Bench BESS, the specific round trip efficiency is not known. However, the 85 percent
round trip efficiency aligns with the current supplier's round trip efficiency that the
Company is actively negotiating.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.

REQUEST FOR PRODUCTION NO. 4: Please provide an updated total cost
estimate for the development and construction of the Boise Bench BESS project, similar
to the table contained in Response to Production Request No. 11 in Case IPC-E-23-20.
RESPONSE TO REQUEST FOR PRODUCTION NO. 4: The following table
provides total cost estimates for the development and construction of the Boise Bench
BESS based on the bid received and evaluated through the RFP process. The cost
estimate does not represent the final pricing as Idaho Power has not yet executed all
agreements associated with the Boise Bench BESS.
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.

REQUEST FOR PRODUCTION NO. 5: Page 46 of Hackett's Direct Testimony
states that "the Company will initiate a purchase order with a battery supplier and enter
into a contract specific to the delivery and contract price of the BESS. Upon notification
of selection by the Evaluation Team following approval by the OPUC of the final shortlist,
the Company's Power Supply department began discussions with suppliers for
procurement of the BESS but has not yet executed a purchase order." Please respond to
the following:
a. Has the Company executed any contract to purchase the 150 MW BESS from a
supplier?
b. If so, please provide a copy of the contract; or
c. If not, when does the Company plan to execute the contract?
RESPONSE TO REQUEST FOR PRODUCTION NO. 5:
a. No.
b. Not applicable.
c. The Company is in active negotiations with various suppliers and expects to
execute a contract in June 2024.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.

REQUEST FOR PRODUCTION NO. 6: In Hackett's Testimony, he stated, "Idaho
Power will enter into a Long-Term Services Agreement for [operational and maintenance
costs ("O&M")] services performed for the energy storage project following commercial
operation of the project." Hackett at 47. Please explain if the estimated cost of this contract
was included in the Company's final proposal of the Boise Bench BESS.
a. If the Company has an executed Long-Term Services Agreement, please provide
the Agreement; and
b. Please provide the estimated cost of the Long-Term Services Agreement.
RESPONSE TO REQUEST FOR PRODUCTION NO. 6:
a. Idaho Power has not yet executed a Long-Term Services Agreement ("LTSA") for
the Boise Bench BESS but anticipates one will be executed in June 2024.
b. For modeling of the 2026 RFP bids, the Company used an estimate of $0.67/kW-
month with annual inflation of 3 percent for LTSA expenses. This assumption was
used for all BESS asset purchase bids and based on quotes Idaho Power has
received for other large-scale BESS O&M contracts. For the Boise Bench BESS
project, the assumption results in LTSA expenses of $1.2 million in year one.
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 TO IDAHO POWER COMPANY- 9

REQUEST FOR PRODUCTION NO. 7: Please explain in detail how the Company
models when to charge the Boise Bench BESS. Additionally, please explain the following:
a. Please explain how the Company will initiate charging as part of operations;
b. Please explain in detail what energy sources will be used to charge the Boise
Bench BESS and how these resources are determined; and
c. Please describe how the energy sources will vary between seasons.
RESPONSE TO REQUEST FOR PRODUCTION NO. 7: The Company models
BESS in AURORA for the RFP the same way it does in the Integrated Resource Plan, a
BESS has the ability to charge and discharge according to its nameplate MW, storage
capacity (duration), and round-trip efficiency. It is modeled as prioritizing net-demand
hours for discharge, meaning AURORA generally prioritizes charging the BESS at
combined low demand and high renewable output hours of the day and discharging the
BESS at high demand and low renewable output hours.
a. As with any of its resources, Idaho Power intends to send dispatch signals (i.e.,
initiate charging and discharging of the BESS) through automated signals from
Idaho Power's scheduling systems to the California Independent System Operator
Energy Imbalance Market systems, which then send Dispatch Operating Targets
to the units. The Company also has the ability to send dispatch signals directly to
the BESS (as it does with other units) when necessary.
b. Idaho Power intends to charge the BESS when it is most economical to do so and
to ensure the BESS is charged in time for peak load hours or the hours of highest
need. The resources that are available and are the most economic will vary
throughout the year and potentially even day by day. On some days, and in
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY- 10

particular in some times of year (i.e., summer), solar resources may be the lowest-
cost available resource with which to charge, and on other days or times of year,
other resources, such as wind, gas, hydro, or market purchases, may be the
lowest-cost available resource. Idaho Power determines the optimal charge time
and most economic resource available based on consideration of its load forecast
and obligations and available resources and their dispatch price for the given day
or set of hours. Given that the Boise Bench BESS will not be operational until 2026,
and that Idaho Power is adding multiple resources to its system between now and
then, the modeling referenced above is the best estimation of when and how the
BESS will be charged.
c. See the response to part (b). Generally speaking, Idaho Power has the most solar
generation on its system in the summer months, so summer is when the Company
has the ability to charge from solar the most. In the fall and spring, Idaho Power
often has strong wind generation on its system that could be used for charging. In
the winter, solar generation is generally lower than in other seasons, and wind
generation availability depends on the weather and day. Throughout the year,
Idaho Power can also use generation from hydro, coal, gas, or market purchases,
depending on the availability of those resources and the dispatch or market prices.
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- 11

REQUEST FOR PRODUCTION NO. 8: Please explain how the Company modeled
Renewable Energy Credits ("RECs"), Investment Tax Credits ("ITCs"), and Production
Tax Credits ("PTCs") in AURORA. Please provide the model input values for these
credits. Please provide the underlying data the Company relied on to determine those
values.
RESPONSE TO REQUEST FOR PRODUCTION NO. 8: The Company modeled
RECs consistent with the 2023 IRP, as a variable cost offset to Idaho Power solar and
wind output. The 2023 IRP REC price forecast can be found on page 26 of the 2023 IRP
— Technical Appendix C.' Please also see Response to Staff's Request No. 8 —
Confidential Attachment for further underlying data on the REC price forecast.
ITCs are factored into the fixed capital cost that is then used as an input into
AURORA, consistent with the 2023 IRP. For Company-owned BESS projects, the 30
percent ITC is used in the calculation of the revenue requirement and fixed capital cost.
PTCs are accounted for as a variable cost offset to potential Company-owned solar
and wind output, but do not apply to BESS projects. The base PTC amount modeled for
2022 was $27.50/MWh on an after-tax basis or a $37.03/MWh reduction to the revenue
requirement calculation (pretax dollars). The PTC is adjusted for inflation annually
consistent with Internal Revenue Service practices.
The response to this Request is sponsored by John Wonderlich, Finance Team
Leader II, Idaho Power Company.
Idaho Power 2023 IRP, Appendix C.
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY- 12

REQUEST FOR PRODUCTION NO. 9: Several proposals for the 2026 RFP
included Long-Duration Energy Storage ("DFES"). Please provide an overview of the
LDES technologies proposed, the range of nominal storage capacities, and the range of
discharge durations.
RESPONSE TO REQUEST FOR PRODUCTION NO. 9:
Proposal Technology Nameplate Capacity Discharge Nominal
Type Duration Storage
Capacity
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 TO IDAHO POWER COMPANY- 13

REQUEST FOR PRODUCTION NO. 10: Page 8 of Exhibit No. 6 shows an
example of the 60 stochastic iterations for various portfolios. Please provide the actual
stochastic results for the portfolio containing this BESS project and for the portfolios
containing the other 2026 shortlist projects.
RESPONSE TO REQUEST FOR PRODUCTION NO. 10: Please see the
Response to Staff's Request No. 10 — Confidential Attachment for the results of the
stochastic iterations for the various portfolios.
The response to this Request is sponsored by Eric Hackett, Projects and Resource
Development Director, Idaho Power Company.
DATED at Boise, Idaho this 29th day of May 2024.
DONOVAN E. WALKER
Attorney for Idaho Power Company
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY- 14

CERTIFICATE OF SERVICE
I HEREBY CERTIFY that on the 29th day of May, 2024, 1 served a true and correct
copy of 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
Chris Burdin 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 Chris.Burdin(a-).puc.idaho.gov
PO Box 83720
Boise, ID 83720-0074
Micron Technology, Inc. Hand Delivered
Austin Rueschhoff U.S. Mail
Thorvald A. Nelson Overnight Mail
Austin W. Jensen FAX
Holland & Hart LLP X Email darueschhoff(a-).hollandhart.com
555 17th Street, Suite 3200 tnelson(c)_hollandhart.com
Denver, CO 80202 awjensen hollandhart.com
aclee(o)_hollandhart.com
mamcmillen(a-).hollandhart.com
Micron Technology, Inc. Hand Delivered
Jim Swier U.S. Mail
8000 S. Federal Way Overnight Mail
Boise, ID 83707 FAX
X Email iswier ,micron.com
Stacy Gust, Regulatory Administrative
Assistant
IDAHO POWER COMPANY'S RESPONSE TO THE FIRST PRODUCTION REQUEST OF THE
COMMISSION STAFF TO IDAHO POWER COMPANY- 15