20230829IPC to Staff 3-23 - Redacted.pdf

DONOVAN WALKER
Lead Counsel
[e-mail]

August 29, 2023

VIA ELECTRONIC FILING

Jan Noriyuki, Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd., Bldg 8,
Suite 201-A (83714)
PO Box 83720
Boise, Idaho 83720-0074

Re: Case No. IPC-E-23-20
In the Matter of Idaho Power Company’s Application for a Certificate of Public
Convenience and Necessity to Acquire Resources to be Online in Both 2024
and 2025 and for Approval of an Energy Storage Agreement with Kuna Bess,
LLC

Dear Ms. Noriyuki:

Attached for electronic filing please find a redacted version of Idaho Power
Company’s Response to the Second Production Request of the Commission Staff in the
above matter.

Idaho Power Company’s Response to the Second Production Request of the
Commission Staff contains confidential information within the response and attachments. A
confidential version of the response and attachments will be provided separately via an
encrypted email to parties who sign the protective agreement.

Please feel free to contact me directly with any questions you might have about this
filing.

Very truly yours,

Donovan E. Walker
DEW:cd
Enclosures
RECEIVED
Tuesday, August 29, 2023 4:49:34 PM
IDAHO PUBLIC
UTILITIES COMMISSION

CERTIFICATE OF ATTORNEY

ASSERTION THAT INFORMATION CONTAINED IN AN IDAHO PUBLIC UTILITIES
COMMISSION FILING IS PROTECTED FROM PUBLIC INSPECTION

Idaho Power Company’s Application for a Certificate of Public Convenience and
Necessity to Acquire Resources to be Online in Both 2024 and 2025 and for
Approval of an Energy Storage Agreement with Kuna Bess, LLC

Case No. IPC-E-23-20

The undersigned attorney, in accordance with Commission Rules of Procedure 67,
believes that the Attachment No(s). 9, 13, and 23 to Idaho Power Company’s Idaho Power
Company’s Response to the Second Production Request of the Commission Staff to
Idaho Power Company, dated August 29, 2023, contain information that Idaho Power
Company and a third party claims is a confidential trade secret and/or trade secret as
described in Idaho Code § 74-101, et seq., and/or § 48-801, et seq in that the redacted
information contains confidential negotiated terms and conditions, confidential bidder
information and competitive bid submissions, as well as confidential financial information
about the Company. As such, it is protected from public disclosure and exempt from public
inspection, examination, or copying.

DATED this Tuesday, August 29, 2023.

Donovan Walker
Counsel for Idaho Power Company

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 1

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]

Attorney for Idaho Power Company

BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION

IN THE MATTER OF IDAHO POWER
COMPANY’S APPLICATION FOR A
CERTIFICATE OF PUBLIC CONVENIENCE
AND NECESSITY TO ACQUIRE
RESOURCES TO BE ONLINE IN BOTH
2024 AND 2025 AND FOR APPROVAL OF
AN ENERGY STORAGE AGREEMENT
WITH KUNA BESS LLC.
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CASE NO. IPC-E-23-20

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

COMES NOW, Idaho Power Company (“Idaho Power” or “Company”), and in
response to the Second Production Request of the Commission Staff (“Commission” or
“Staff”) to Idaho Power Company dated August 22, 2023, herewith submits the following
information:

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 2

STAFF REQUEST FOR PRODUCTION NO. 3: The following sources show an
incremental capacity deficit of 125 MW in 2025:
· The 2021 Integrated Resource Plan ("2021 IRP") at 142 and 170;
· Hackett's Direct Testimony at 8;
However, the following sources show an incremental capacity deficit of 115 MW in
2025:
· Application at 6;
· Ellsworth's Direct Testimony at 23; and
Please reconcile the numbers.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 3: The capacity need
of 125 MW in 2025 was first identified in the 2021 IRP load and resource balance, as seen on
pages 21-22 of the 2021 IRP - Appendix C. When Idaho Power’s 2022 All Source Request for
Proposals for Peak Capacity and Energy Resources (“2022 RFP”) was issued on December 30,
2021, the 2025 capacity deficiency initially identified was 115 MW, however shortly thereafter
the Company issued Addendum No. 3 clarifying that, consistent with the 2021 IRP, the capacity
need in 2025 was an incremental 125 MW. Please see the Attachment – Response to Staff Request
No. 3 for the addendum issued on January 29, 2022.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 3

STAFF REQUEST FOR PRODUCTION NO. 4: What is the energy source that will be
used to charge the Kuna Battery Energy Storage System ("BESS")?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 4: The Kuna BESS
will be charged by available resources, including Idaho Power system resources and potentially
economic purchased energy, during lower-load hours in anticipation of discharging during peak
load hours.
The response to this Request is sponsored by Eric Hackett, Senior Manager Projects and
Design, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 4

STAFF REQUEST FOR PRODUCTION NO. 5: Round Trip Efficiency (RTE) =
Discharging Energy ÷ Charging Energy. Exhibit No. 6 of Hackett's Direct Testimony. The
Application states that Section 1.1 of the ESA contains a Guaranteed Round-Trip Efficiency as of
the Commercial Operation Date of 85.9 percent which decreases 0.22 percent annually. Please
respond to the following.
a. Please explain whether it is typical to have a Guaranteed Round-Trip Efficiency lower than
90 percent for a new BESS project and provide evidence to support your answer; and
b. Please explain whether a 0.22 annual decrease is typical and provide evidence to support
your answer.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 5:
a. An Alternating Current (“AC”) to AC round-trip efficiency of 85.9 percent is comparable to
Battery Energy Storage Systems (“BESS”) in the industry. It is important to understand the
Round-Trip Efficiency (“RTE”) identified in the contract for the Kuna BESS is measured at
the point of interconnection to Idaho Power’s grid and includes electrical losses for both
charging and discharging through the generator step-up transformer, medium-voltage
transformer, and inverters, as well as electrical losses intrinsic in the batteries themselves.
The National Energy Renewable Laboratories (NREL) assumes an 86 percent RTE in its
Annual Technology Baseline1. In addition, the Pacific Northwest National Laboratories
(PNNL) shows an 86 percent RTE for Li-Ion LFP energy storage2. Idaho Power expects the
RTE to be above the guaranteed 85.9 percent and has included an adjustment to the Monthly
Capacity Payment for measured RTE below the Guaranteed Round-Trip Efficiency in

1 NREL ATB: Utility-Scale Battery Storage | Electricity | 2022 | ATB | NREL
2 PNNL URL: Final - ESGC Cost Performance Report 12-11-2020.pdf (pnnl.gov)

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 5

section 2.3(a) of the Energy Storage Agreement included as Confidential Exhibit No. 6 to
Mr. Hackett’s Direct Testimony.
b. A 0.22 percent annual decrease is comparable to industry standards and ensures the Kuna
BESS maintains a round-trip efficiency above 81.9 percent at the end of life after 20 years.
The US Department of Energy published an Energy Storage Technology and Cost
Characterization report where it shows a 0.5 percent degradation for Li-Ion energy storage
technology3.
The response to this Request is sponsored by Eric Hackett, Senior Manager Projects and
Design, Idaho Power Company.

3 DOE HydroWires URL: Storage Cost and Performance Characterization Report (energy.gov)

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 6

STAFF REQUEST FOR PRODUCTION NO. 6: The Application states that at the time
the proposals for 2022 Request For Proposals ("2022 RFP") were being evaluated, the 2025
capacity deficiency had increased, so Idaho Power selected the next most cost-effective resource
to meet the 2025 capacity deficiency. Application at 9. Page 18 of Ellsworth's Direct Testimony
states that the updated capacity deficiency in 2025 is 178 MW. Please respond to the following:
a. When did the 2025 capacity deficiency increase to 178 MW?
b. Please provide the Load and Resource Balance ("L&R") for the 178 MW;
c. Please confirm that reasons listed on Pages 10 and 11 of Ellsworth's Direct Testimony are
all the reasons that caused the deficit increase from the previous 2025 capacity deficiency
identified in the 2021 IRP to the updated incremental 178 MW deficit in 2025. If not, please
provide additional reasons; and
d. Please provide the updated L&R that shows the updated capacity position of 13 MW of
capacity length in 2024, after the proposed resources are added.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 6:
a. The increase in the 2025 capacity shortfall was identified in May 2023.
b. As described in the Direct Testimony of Jared Ellsworth and discussed in the MATLAB
Workshop with Staff on August 21, 2023, Idaho Power currently utilizes the Loss of
Load Expectation (“LOLE”) methodology to assess system reliability via the internally
developed Reliability & Capacity Assessment Tool (“RCAT”), which is capable of
producing outputs such as the capacity position for a given year. While the Company is
able to represent the RCAT’s input and output data in the form of a Load & Resource
(“L&R”) balance, it is the capacity position determined through the LOLE analysis that
drives resource selection decisions. Because the L&R balance is a representation of the

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 7

RCAT inputs and results, a L&R balance is not created for every step in the project
analysis process. Instead, see Attachment 1 – Response to Staff’s Request No. 6(b) which
includes:
 The system reliability analysis capacity position results by test year which
produce the 178 MW capacity shortfall for 2025,
 The monthly peak load forecast for 2025,
 The flexible resource monthly capacities and associated Equivalent Forced
Outage Rates during Demand (“EFORd”) utilized in the RCAT to develop the
outage table, and
 The variable and energy limited resource nameplates utilized in the RCAT.
c. No, the reasons listed on Pages 10 and 11 of Ellsworth’s Direct Testimony are not the only
drivers of the changes in the 2025 capacity shortfall. As described further in Mr.
Ellsworth’s testimony, beginning on page 16, the following updates were made:
 The load forecast was updated,
 Current transmission reservations were included,
 Resource inputs were updated to include new resource additions including (1) the
Black Mesa project, a 40 MW solar photovoltaic (“PV”) power purchase agreement
(“PPA”) in combination with a 40 MW four-hour duration battery storage facility,
(2) the Hemingway 80 MW four-hour duration battery storage project in 2023 and
an additional 12 MW of four-hour duration battery storage in 2024, (3) the 11 MW
four-hour duration battery storage at various distribution substations, (4) the
Franklin project, a 100 MW solar PV PPA in combination with a 60 MW four-hour

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 8

duration battery storage facility, and the (5) 200 MW Pleasant Valley solar PV
project in 2025,
 The planned refurbishment of one hydro unit per year, for three years, at the
American Falls facility, reducing the overall resource availability,
 The 20 MW derate of Langley Gulch through the fall of 2025 due to parts failure
and supply chain issues of those higher capacity parts, and
 Due to uncertainty around their ability to come online, the removal of 72 MW of
nameplate capacity of two solar PV PURPA projects that were expected to be
online by the summer of 2025.
d. As explained in part (b) of this request, Idaho Power does not create an L&R balance and
instead has provided the inputs and results of the RCAT analysis in Attachment 2 –
Response to Staff’s Request No. 6(d).
The response to this Request is sponsored by Jared Ellsworth, Transmission, Distribution and
Resource Planning Director, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 9

STAFF REQUEST FOR PRODUCTION NO. 7: The Application states that during
preparation of the 2023 IRP, as the load and resource balance was refreshed, it was determined
that a capacity shortfall still exists in 2024, so the Company added a 24 MW BESS to meet the
2024 capacity deficiency. Application at 10. Page 18 of the Ellsworth's Direct Testimony states
that the shortfall is 8 MW. Please respond to the following:
a. Please explain when it was determined that the 8 MW shortfall still existed in 2024;
b. Please provide the L&R for the 8 MW shortfall;
c. Please explain what caused the 8 MW shortfall since the last deficit of 103 MW was met by
resources proposed in Case No. IPC-E-23-05. In your answer, please rule out factors that
have contributed to the determination of the 103 MW deficit; and
d. Please provide the updated L&R that shows the updated capacity position of 6 MW of
capacity length in 2025, after the proposed resources are added.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 7:
a. The additional 8 MW capacity shortfall in 2024 was identified in May 2023, at the same time
the 178 MW capacity shortfall in 2025 was identified.
b. As explained in the Response to Staff’s Request for Production No. 6(b), Idaho Power does
not create an L&R balance and instead has provided the inputs and results of the RCAT
analysis in Attachment 1 – Response to Staff’s Request No. 7(b).
c. The system reliability analysis performed and explained in the Response to Staff’s Request
for Production No. 6(c) identified both the 8 MW capacity shortfall in 2024 and the 178 MW
capacity shortfall in 2025. As described in the Direct Testimony of Jared Ellsworth (pg. 18),
the following updates were made to the system reliability evaluation, including (1) reduced
winter resource availability associated with Capacity Benefit Margin (“CBM”), (2)

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 10

identification of an over-allocation of capacity of a resource in the LOLE calculation, and
(3) the unexpected 20 MW derate at Langley Gulch.
d. As explained in the Response to Staff’s Request for Production No. 6(b), Idaho Power does
not create an L&R balance and instead has provided the inputs and results of the RCAT
analysis in Attachment 2 – Response to Staff’s Request No. 7(d).
The response to this Request is sponsored by Jared Ellsworth, Transmission, Distribution
and Resource Planning Director, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 11

STAFF REQUEST FOR PRODUCTION NO. 8: Page 18 of Ellsworth's Direct
Testimony states that both the 8 MW deficit in 2024 and the 178 MW deficit in 2025 are based on
the assumption that the Company can compress the American Falls outages into nine-months and
maintain full American Falls capacity through the summer months. Please respond to the
following:
a. Please explain whether this assumption is still reasonable;
b. If the Company is not able to restore American Falls to full capacity for the summer, what
are the capacity deficits in 2024 and 2025, respectively? Please provide the L&Rs that show
these capacity deficits; and
c. After the proposed resources are added, the capacity position becomes 13 MW in length in
2024 and 6 MW in length in 2025, assuming the Company can restore the American Falls
power plant to full capacity prior to the summer of each year. Please explain whether 13 MW
and 6 MW are reasonable amounts of capacity lengths.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 8:
a. Yes, the Company is executing on a plan to have all American Falls units back in operation
for the summer of 2024.
b. Referencing Page 24 of Ellsworth Testimony, if Idaho Power has a unit out at American
Falls during the summer operating seasons, the Company will have 0 MW of capacity
length in 2024, and an 8 MW capacity shortfall in 2025. As explained in the Response to
Staff’s Request for Production No. 6(b), Idaho Power does not create an L&R balance and
instead has provided the 2024 and 2025 inputs and results of the RCAT analysis in the
corresponding attachment.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 12

c. Given current levels of high load growth in southern Idaho, the time required to acquire
resources to meet incremental needs, and supply chain constraints that can lead to
unexpected delays (where resources are placed in-service late after key operational
windows), the Company believes 13 MW and 6 MW of length in 2024 and 2025
respectively is sufficient to maintain Idaho Power’s system resource adequacy (a LOLE
target of 0.1 event-days per year) but would prefer to have additional length to ensure
continued system reliability.
The response to this Request is sponsored by Jared Ellsworth, Transmission, Distribution,
and Resource Planning Director, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 13

STAFF REQUEST FOR PRODUCTION NO. 9: Please respond to the following
regarding the Battery Energy Storage Agreement ("BESA") executed by the Company and Powin
on June 8, 2023.
a. Please provide a complete copy of the contract and include Exhibit E of the contract in your
response;
b. Please confirm this contract is based on a 36 MW nameplate capacity, which includes both
the 12 MW BESS in Case No. IPC-E-23-05 and the 24 MW BESS in this case; and
c. If confirmed, please provide the page number of the contract that references the 36 MW.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 9:
a. The Battery Energy Storage Agreement (“BESA”) is attached as Confidential Attachment -
Response to Staff Request No. 9.
b. Yes, the BESA is for 36 MW nameplate capacity.
c. The 36 MW nameplate capacity is found in Exhibit C on page 104 included in the BESA as
well as Exhibit F-1 on page 121.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 14

STAFF REQUEST FOR PRODUCTION NO. 10: Please provide a breakdown of the
total cost estimates for the development and construction of the 24 MW BESS, similar to the table
contained in Response No. 43(b) in Case No. IPC-E-23-05.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 10:
The following table provides the most recent total cost estimate for the development and
construction of the 24 MW BESS:
Powin 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 Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 15

STAFF REQUEST FOR PRODUCTION NO. 11: Please provide a breakdown of the
total cost estimates for the development and construction of the 77 MW BESS, similar to the table
contained in Response No. 43(b) in Case No. IPC-E-23-05.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 11:
The following table provides total cost estimates for the development and construction of
the 77 MW 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 Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 16

STAFF REQUEST FOR PRODUCTION NO. 12: The 77 MW is a reduced capacity
size from the original bid size. Is the levelized cost of capacity for the original size kept the same
for the 77 MW? If not, how can the Company guarantee this resource is the second least-cost
resource?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 12:
Yes. As shown in the Company’s Response to Staff’s Request for Production No. 11, the
cost of Project No. 15 was proportionally scalable and therefore the levelized cost of capacity
between the 150 MW bid and the 77 MW project is the same.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 17

STAFF REQUEST FOR PRODUCTION NO. 13: The Company's Reply Comments in
Case No. IPC-E-23-05 state that "Idaho Power performed a quantitative and qualitative evaluation
with an objective scoring methodology to reasonably evaluate the price and non-price attributes of
each project proposal submitted through the RFP process." Please respond to the following:
a. Please describe the scoring methodology;
b. Please provide the result of the qualitative evaluation, including the score of each project;
c. Please provide the result of the quantitative evaluation, including the score of each project;
and
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 13:
a. Following the initial threshold screen of the project submittals, qualitative and quantitative
evaluations were performed iteratively. The qualitative evaluation ranked the proposals
based on project feasibility, project capability, counterparty profile, and community
stewardship, with each category weighted to ensure the evaluation process is conducted
without bias and yields results that are aligned to Idaho Power’s resource needs. The
qualitative evaluation used 57 unique factors for scoring, under the rating criteria determined
before proposals were received. The qualitative evaluation allows for the relative ranking of
the eligible project submittals to better identify those projects that best meet the Company’s
resource needs.
The quantitative evaluation ranked the proposals by cost through indicative AURORA
scenarios, which allows for the use of a consistent common evaluation tool with consistent
common assumptions in that tool, for reasonable evaluation results. Using the most recent
load forecast at the time, AURORA’s long-term capacity expansion (“LTCE”) modeling
capability was used to develop the least-cost, least-risk portfolio for meeting the 2025

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
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capacity deficiency. Under the LTCE modeling approach, the levelized costs of all 45 project
submittals are input into AURORA as potential resource additions, along with their project
specific operating characteristics and any potential variable costs. The LTCE model
optimizes these potential resource selections based on the performance of each resource
within Idaho Power’s zone, optimizing for the cost function while meeting the Company’s
identified capacity deficiency.
b. The Company will supplement this response with the results of the qualitative evaluation no
later than September 1, 2023
c. There is no score of each project associated with the quantitative evaluation. Rather, through
the indicative AURORA LTCE modeling, the resource addition(s) that result in a least-cost,
least-risk portfolio for meeting the capacity deficiency is selected. In the case of the resources
selected to meet the 2025 capacity deficiency, Project No. 31, the 150 MW energy storage
project, consisting of a 20-year Energy Supply Agreement for a 150 MW battery storage
facility, was selected as the most cost-effective resource. However, because the 2025
capacity need increased following the initial LTCE analysis, the indicative AURORA LTCE
modeling was performed once again, to identify the next most cost-effective resource. To
accomplish this, rather than being identified as a potential resource addition, Project No. 31
was instead identified as an actual resource addition, removing it from the potential resource
additions. This allows the AURORA LTCE modeling to identify the next most cost-effective
resource to fill the remaining capacity deficiency, or Project No. 15, the Idaho Power-owned
77 MW battery storage facility. Once the resources are identified, the AURORA LTCE
modeling is complete as there is no identified capacity deficiency for which a resource
addition must be selected to fill.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 19

The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 20

STAFF REQUEST FOR PRODUCTION NO. 14: Please list all the bids that the
Company received, where the BESS component of "BESS+Solar" and "BESS+Wind" is owned
by the respondent.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 14:
The bids the Company received that include a BESS component owned by the respondent
are those that are identified as having a Battery Storage Agreement (“BSA”) proposal in
Confidential Exhibit No. 5, including Project Nos. 1, 6, 7, 8, 9, 10, 11, 12, 24, 30, 31, 32, 33, 34,
and 35.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 21

STAFF REQUEST FOR PRODUCTION NO. 15: Please confirm that AURORA selects
least-cost resources based on each project's levelized cost of capacity contained in Table 1-3 of
Exhibit No. 5 of Hackett's Direct Testimony and not each project's proposal price contained in
these tables. If not confirmed, please explain how AURORA selects the least-cost resources.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 15:
Yes. AURORA selects least-cost resources based on each project's levelized cost of
capacity for storage projects or any build-transfer agreement project, or levelized cost of energy,
for PPA projects.
The response to this Request is sponsored by Eric Hackett, Senior Manager Projects and
Design, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 22

STAFF REQUEST FOR PRODUCTION NO. 16: Page 23 of Hackett's Direct
Testimony states that "[t]he remaining project, Project No. 34, did not have any available
transmission capacity and therefore did not make the short list. Similarly, although modeled as
part of the LTCE analysis, it was determined that Project Nos. 2, 3, 4, 5, and 33 also did not have
any available transmission capacity." Please respond to the following:
a. Was Project No. 34 included in the LTCE analysis?
b. If not, why was Project No. 34 not included in the LTCE analysis, while Project Nos, 2, 3,
4, 5, and 33 were included?
c. Is "available transmission capacity" a requirement that a bid must meet?
d. If so, why were Project Nos. 2, 3, 4, 5, and 33 still modeled as part of the LTCE analysis,
when they did not meet the transmission requirement?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 16:
a. No.
b. Idaho Power began building the AURORA LTCE model while simultaneously evaluating
the bids in preparation of modeling. Project Nos. 2, 3, 4, 5, and 33 were built into the model.
Because Project No. 34 and Project No. 4 have the same operational characteristics (200 MW
long duration energy storage), Project No. 34 was not modeled in the LTCE as it had a higher
levelized cost than Project No. 4 and therefore would not be selected as the least-cost
resource addition.
c. Yes. Section 3.1 - Eligible Products of the RFP requires the Delivery Point be within the
boundary of the Idaho Power Balancing Authority (“BA”) Area, or outside with all necessary
transmission rights to the BA. If a project is not located in Idaho Power’s BA, they must
show viable transmission deliverability to the Idaho Power border. Without confirmation of

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 23

transmission deliverability to the Idaho Power border, the resource is isolated from Idaho
Power’s system and thus does not contribute to reliable load service.
d. These projects were modeled in the LTCE regardless of their lack of transmission availability
as a further assessment of the LTCE modeling discussed in part (b) above. However, these
projects were not selected during the AURORA LTCE modeling.
The response to this Request is sponsored by Eric Hackett, Senior Manager Projects and
Design, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 24

STAFF REQUEST FOR PRODUCTION NO. 17: Page 23 of Hackett's Direct
Testimony states "Project Nos. 25, 26, and 27 were not cost-effective options because of the
limited capacity benefit of the energy storage or surplus only availability of the energy storage."
Please respond to the following:
a. Is it a requirement that projects cannot have attributes of "limited capacity benefit" or
"surplus only availability"?
b. If so, why were Project Nos. 25, 26, and 27 still included in the LTCE analysis, when they
did not meet the requirement?
c. Is it possible for a project to be cost-effective that provides limited capacity benefit or surplus
only availability?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 17:
a. No.
b. See response to (a).
c. Yes. The cost would need to be low enough to overcome the “limited capacity benefit” or
“surplus only availability” and be selected by Aurora (compared to other resource projects
in the RFP).
The response to this Request is sponsored by Eric Hackett, Senior Manager Projects and
Design, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 25

STAFF REQUEST FOR PRODUCTION NO. 18: Pages 24-25 of Hackett's Direct
Testimony states that after the establishment of the short list, the RFP evaluation team provided
another opportunity for developers to update pricing. Five of the shortlist projects provided
updated pricing, where four projects increased pricing and one project decreased pricing. Please
respond to the following:
a. Which projects increased pricing?
b. Which projects decreased pricing?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 18:
a. Following the opportunity to provide updated pricing, Project Nos. 6, 7, 16, and 17 increased
pricing.
b. Following the opportunity to provide updated pricing, Project No. 31 decreased its pricing.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 26

STAFF REQUEST FOR PRODUCTION NO. 19: Page 31 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 RFP evaluation team, 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 77 MW BESS from a supplier?
b. If so, please provide a copy of the contract.
c. If not, when does the Company plan to execute the contract?
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 19:
a. No. Idaho Power has not executed the supply agreement for the 77 MW BESS as suppliers
continue to offer revised and competitive pricing. Idaho Power is actively negotiating a
supply agreement with the selected vendor.
b. See response to (a) above.
c. Idaho Power is in active negotiations with a preferred vendor based on their competitive
price quote and expects to execute the agreement in September 2023. The vendor has aligned
the delivery of the BESS on the timeline established to meet the required June 1, 2025
commercial operation date.
The response to this Request is sponsored by Eric Hackett, Senior Manager Projects and
Design, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 27

STAFF REQUEST FOR PRODUCTION NO. 20: Page 35 of Hackett's Direct
Testimony provides the estimated costs of the 77 MW BESS and the 24 MW BESS. Are the
estimated costs turn-key costs that bring the projects from design to operation? If not, what items
do the estimated costs include? Please provide a breakdown of the estimated costs for each item.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 20:
Yes. The costs provided in Mr. Hackett’s Direct Testimony reflect the estimated costs to
bring the project from design to operation. The costs include purchase and installation of the
batteries and ancillary equipment such as transformers, inverters, cables, networking equipment,
foundations, structures, etc. These costs include full implementation from design and engineering
to procurement and construction. Please see the Company’s Response to Request for Production
Nos. 10 and 11 for estimated line-item costs.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 28

STAFF REQUEST FOR PRODUCTION NO. 21: Please explain why Project No. 16
was not selected, when its levelized cost was the lowest on the short list.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 21:
Project No. 16 is a solar project and therefore the levelized cost reflects the levelized cost
of energy which is not comparable to a levelized cost of capacity (“LCOC”) of storage projects.
Solar projects provide energy, but limited capacity towards Idaho Power’s capacity deficit. Storage
projects provide no energy generation but provide significant capacity towards the Company’s
capacity deficit. The AURORA LTCE model selects the optimal least-cost mix of projects to meet
Idaho Power’s demand and capacity needs based on cost, resource characteristics, and effective
load carrying capability (“ELCC”) or contribution to peak, which did not include Project No. 16
as part of this evaluation.
The response to this Request is sponsored by Eric Hackett, Projects and Design Senior
Manager, Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 29

STAFF REQUEST FOR PRODUCTION NO. 22: Footnote Nos. 21 and 23 in Exhibit
No. 5 of Hackett's Direct Testimony mention price adjustments due to overbuilds.
a. Please explain what the bidders proposed regarding overbuilds in their bids; and
b. Please explain how and why overbuilds affect pricing.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 22:
Battery cells degrade over time. For example, a 100 MW BESS installation with no
overbuild will supply 100 MWs to the system on day one; however, assuming a 3 percent
degradation rate, that same 100 MW BESS will only supply 97 MW to the system after one year.
The degradation rate varies and is a function of time and throughput, or megawatt-hours (“MWh”).
To mitigate the degradation, additional battery segments are added. Most degradation mitigation
plans the Company has observed through project submittals during the recent RFP processes
include an overbuild with a plan to add battery segments in the future when capacity drops below
the desired level. Note, BESS systems are often expressed in units of MWh. For example, a 4-hour
100 MW BESS would supply 400 MWh in a cycle whereas a 100 MW BESS with a 20 percent
overbuild would supply 480 MWhs.
a. As noted in Confidential Exhibit No. 5 of Hackett’s Direct Testimony, Project No. 1 provided
a 12.7 percent overbuild, or day one batteries equivalent to 169 MW, and Project 15 provided
a 17.9 percent overbuild, or day one batteries equivalent to 177 MW.
b. If one bidder overbuilds 25 percent and another has a 0 percent overbuild and their price per
MW was equal excluding the overbuild, the cost of the project with the overbuild would be
25 percent higher than the project with no overbuild. The results would indicate the
overbuild project is more costly. However, the project without the overbuild would need to
add batteries during year one, year two, year three, and so on to mitigate degradation. Another

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 30

approach to degradation mitigation is to enter into a battery augmentation agreement with
the manufacturer of the battery cells. Under an augmentation agreement, the manufacturer
might require the buyer to pay a fixed annual fee over the 20-year life of the project and the
manufacturer would then add batteries as necessary to get back to the original agreed upon
MW capacity.
In addition to the above impacts on pricing, the overbuild portion is assumed to benefit
from the 30 percent Investment Tax Credit available under the Inflation Reduction Act. For
project evaluation purposes and to ensure bids of varying overbuild sizes are comparable, the
Company adjusts the overbuild back to zero for each project, and then adds annual augmentation
costs through the life of the project. This puts projects with varying overbuild sizes on a
comparable basis and assumes capacity output stays flat over the life of the project.
The response to this Request is sponsored by John Wonderlich, Finance Team Leader,
Idaho Power Company.

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 31

STAFF REQUEST FOR PRODUCTION NO. 23: Please provide the overall levelized
cost and annual cost and benefit streams with a breakdown of the cost and benefit components for
Project Nos. 6, 13, and 17 on the short list, in addition to the separate levelized costs for the solar,
wind, or BESS components already provided in the Application.
RESPONSE TO STAFF’S REQUEST FOR PRODUCTION NO. 23:
Please see the levelized cost calculations and annual costs for Project Nos. 6, 13, and 17 in
Confidential Attachment 1 – Response to Staff Request No. 23, Confidential Attachment 2 –
Response to Staff Request No. 23, and Confidential Attachment 3 – Response to Staff Request
No. 23, respectively. Note, Project No. 6 was evaluated including imputed debt in this calculation
but was also evaluated excluding imputed debt. Also, note that Project Nos. 6 and 13 were removed
from consideration citing inability to meet the June 1, 2025, commercial operation date.
The response to this Request is sponsored by John Wonderlich, Finance Team Leader,
Idaho Power Company.

DATED at Boise, Idaho this 29th day of August 2023.

DONOVAN E. WALKER
Attorney for Idaho Power Company

IDAHO POWER COMPANY’S RESPONSE TO THE SECOND PRODUCTION REQUEST OF THE
COMMISSION STAFF - 32

CERTIFICATE OF SERVICE

I HEREBY CERTIFY that on the 29th day of August 2023, I served a true and
correct copy of Idaho Power Company’s Response to the Second Production Request of
the Commission Staff upon the following named parties by the method indicated below,
and addressed to the following:

Commission Staff
Chris Burdin
Deputy Attorney General
Idaho Public Utilities Commission
11331 W. Chinden Blvd., Bldg No. 8
Suite 201-A (83714)
PO Box 83720
Boise, ID 83720-0074

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Christy Davenport
Legal Administrative Assistant