20240722Staff 82-118 to PAC.pdf

RECEIVED
Monday, July 22, 2024, 2:51 PM
IDAHO PUBLIC
ADAM TRIPLETT UTILITIES COMMISSION
DEPUTY ATTORNEY GENERAL
IDAHO PUBLIC UTILITIES COMMISSION
PO BOX 83720
BOISE, IDAHO 83720-0074
[phone]
IDAHO BAR NO. 10221
Street Address for Express Mail:
11331 W CHINDEN BLVD, BLDG 8, SUITE 201-A
BOISE, ID 83714
Attorney for the Commission Staff
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION )
OF ROCKY MOUNTAIN POWER FOR ) CASE NO. PAC-E-24-04
AUTHORITY TO INCREASE ITS RATES )
AND CHARGES IN IDAHO AND APPROVAL ) SIXTH PRODUCTION
OF PROPOSED ELECTRIC SERVICE ) REQUEST OF THE
SCHEDULES AND REGULATIONS ) COMMISSION STAFF
TO ROCKY MOUNTAIN
POWER
Staff of the Idaho Public Utilities Commission, by and through its attorney of record,
Adam Triplett, Deputy Attorney General, requests that PacifiCorp d/b/a Rocky Mountain Power
("Rocky Mountain Power" or the "Company")provide the following documents and information
as soon as possible, but no later than MONDAY, AUGUST 12, 2024.
This Production Request is to be considered as continuing, and the Company is requested
to provide, by way of supplementary responses, additional documents that it, or any person
acting on its behalf, may later obtain that will augment the documents or information produced.
Please provide answers to each question, supporting workpapers that provide detail or are
the source of information used in calculations, and the name,job title, and telephone number of
the person preparing the documents. Please also identify the name,job title, location, and
telephone number of the record holder.
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 1 JULY 22, 2024

In addition to the written copies provided as response to the requests,please provide all
Excel spreadsheets and electronic files with formulae intact and enabled.
REQUEST NO. 82: Please provide a detailed description of the Company's
weather/temperature normalization method used to normalize revenues, system peak, energy
loads, net power costs, and any other items normalized by this method. In the description, please
identify any changes in the method from Case No. PAC-E-21-07. Please provide any
workpapers supporting the weather/temperature normalization method, in electronic format with
links intact and formulae enabled, for each item that is normalized including weather spline
models and calculations of the weather adjustment.
REQUEST NO. 83: Please provide a detailed description of the Company's method for
normalizing energy sales and revenue. In the description, please identify any changes in the
method from Case No. PAC-E-21-07. Please provide any workpapers supporting the energy
sales and revenue normalization method, in electronic format with links intact and formulae
enabled.
REQUEST NO. 84: The document"7 Direct Testimony and Exhibit Ramon J Mitchell
CONF" does not include the confidential page of Exhibit No. 27 (General Electric Model 717.04
Gas Turbine). Please provide the confidential version of Exhibit No. 27.
REQUEST NO. 85: Please confirm that bid prices in EDAM are set by each
participating utility. Also, please confirm that each participating utility can set bid prices high to
avoid dispatching a resource.
REQUEST NO. 86: Mitchell's Direct Testimony states that Wyoming has a sharing
band, while Oregon and Washington have both dead bands and sharing bands in their net power
cost adjustment mechanisms. Please explain each of the three state's current sharing policies
and provide an example for each in a worksheet with formulae intact.
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 2 JULY 22, 2024

REQUEST NO. 87: Eller's Direct Testimony states that"the Company will retain
RECs for retirement based on a percentage of participating customers' aggregated load data in
the calendar year immediately preceding the Program Year and based on Idaho-allocated
Company RECs...Participation in this Program will also require customers to forego revenue
credits in their rates from sales of Company entitled RECs from the RRA." Please explain
whether RECs to be retired can exceed Idaho-allocated RECs.
REQUEST NO. 88: Please explain why the Company does not intend to engage in
marketing efforts for the REC Option Program.
REQUEST NO. 89: Pages 12 and 13 of Eller's Direct Testimony states that the number
of RECs to be retired for the REC Option Program is based on the aggregated load for
participating customers multiplied by a percentage of renewable resource generation from
PacifiCorp's system, and the initial percentage of 20%. Please respond to the following:
a. Please explain and illustrate through examples that non-participating customers will
receive the amount of REC revenue credits that they currently receive;
b. Please explain and illustrate generally whether the Company will financially benefit
from the program. In your answer,please explain if the Company can benefit by
determining which RECs for each resource type will be retired as described in
proposed Schedule No. 74;
c. Please explain why 20% is a reasonable starting percentage; and
d. Please explain whether the number of retired RECs determined under this method
generally aligns with the value of the foregone revenue credits that the participating
customers would have received from the sales of the RECs. Please provide evidence
to support your answer.
REQUEST NO. 90: Page 9 of Eller's Direct Testimony states that"Company witness
McCoy describes how the REC revenue forgone by participating customers would remain in the
existing balancing account and be credited to Idaho's non-participating customers through the
RRA." Please respond to the following:
a. Please provide justification for the statement in the quote; and
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 3 JULY 22, 2024

b. Please explain where the forgone revenue comes from if the RECs are retired.
REQUEST NO. 91: Please respond to the following regarding wheeling revenue:
a. Please confirm that all the OATT wheeling revenue is recorded in FERC Account
456; and
b. Please state whether OATT wheeling revenue is trued up in the ECAM. If so,please
explain how. If not, please explain why.
REQUEST NO. 92: Please respond to the following regarding Day-Ahead/Real-Time
("DA/RT") Adjustments discussed in Mitchell's Direct Testimony:
a. Please explain how the Official Forward Price Curve ("OFPC") is determined;
b. Please explain why OFPC is used in calculating NPC, instead of the market prices
determined by the Aurora model run;
c. Please explain and provide workpapers illustrating how the OFPC forecast is scaled
to hourly buckets; and
d. Please explain how the percentage-of-market-price adders are determined based on
historical data from 2020 to 2023 and provide an example to illustrate the calculation.
In the explanation, please explain how hourly scaled average market-indexed prices
and hourly scaled average Company purchase prices are determined.
REQUEST NO. 93: Page 57 of Mitchell's Direct Testimony states that "trapped energy
is a modeling concept only and does not exist in actual operations. It represents any excess
generation that cannot be used to serve load due to transmission constraints or system-level
oversupply." Please explain why trapped energy does not exist in actual operations and how
Aurora resolves the issue.
REQUEST NO. 94: Please explain the two FED Renewable Energy Tax Credit line
items on Page 116 of Exhibit No. 48 of McCoy's Direct Testimony.
REQUEST NO. 95: Please respond to the following regarding Page 117 of Exhibit No.
48 of McCoy's Direct Testimony:
a. Why are there two levels of Credit Rate Per kWh dependent on their in-service dates?
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 4 JULY 22, 2024

b. For projects placed in-service after 2022, why do generation amounts need to be
adjusted by five times and then by another 110%?
REQUEST NO. 96: Does Aurora treat PURPA energy as non-curtailable energy? If so,
how?
REQUEST NO. 97: For PPAs, does Aurora curtail these resources according to their
contracts?
REQUEST NO. 98: Please explain whether curtailment only applies to wind, not solar,
in the Aurora model.
REQUEST NO. 99: Please respond to the following regarding file"Table NPC Dollar
and Table NPC MWh CONF 2023 Normalized Load.xlsx":
a. Please define "Special Sales for Resale", "Mid-Columbia Contracts", "Storage &
Exchange", "System Balancing Purchases", "Net Interchange", "U. of F. Expense",
and"Other Generation Expense" on Tab "Source".
b. Please explain the difference between"Long Term Firm Sales", "Short Term Firm
Sales", and"System Balancing Sales".
c. Please explain the difference between"Long Term Firm Purchases", "Short Term
Firm Purchases", and"System Balancing Purchases"?
d. Please explain why"Other Generation Expense" on Tab "Source" is not reflected on
Tab "Table(s)NPC Dollar and MWh".
REQUEST NO. 100: Please respond to the following regarding Jim Bridger on Tab
"NPC Summary" of file "ID_GRC_2025_2023 Normalized Load.xlsm", given the in-service
dates of April 2024 for Jim Bridger units 1 and 2 as a gas plant:
a. Please explain how each month's coal fuel cost is determined for Jim Bridger(Line
234); and
b. Please explain how each month's gas fuel cost is determined for Jim Bridger (Line
246).
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 5 JULY 22, 2024

REQUEST NO. 101: Please respond to the following regarding PURPA QFs:
a. Please explain how generation amounts of QFs are determined in calculating NPC;
and
b. Please confirm that QF generation is treated as a must-take resource in Aurora.
REQUEST NO. 102: Page 61 of Mitchell's Direct Testimony states that"on average, a
minimum of 75 percent of each month's largest generation deficit is hedged in the first quarter of
the future (e.g., in December 2024 this would apply to the first quarter of 2025)." Furthermore,
Page 62 of Mitchell's Direct Testimony states that quarterly 25 MW energy blocks of heavy or
light load hour products are loaded into the model to reflect the Company's hedging policy.
Please provide an example illustrating these statements.
REQUEST NO. 103: Please provide the workpapers for determining the "normal hydro
and temperature conditions" as explained on Page 91 of McCoy Exhibit No. 48.
REQUEST NO. 104: For purposes of determining the NPC impact of modeling
changes, according to Mitchell's Direct Testimony, the Company uses a 2025 forecasted load.
Please respond to the following:
a. Please explain whether the expected 2025 forecast load is temperature-normal (i.e.
(Normal based on the historic 20-year rolling window) and whether the extreme
weather adjustment is applied or not; and
b. Please explain why the Company didn't use the 2023 weather-normalized load to do
the analysis.
REQUEST NO. 105: Please explain if the method and resulting loads used to determine
the temperature-normalization revenue adjustment discussed on Page 41 of McCoy Exhibit No.
48 are the same loads used as the "Normal" loads prior to adding the extreme weather adjustment
used for NPC.
REQUEST NO. 106: Page 29 of Mitchell's Direct Testimony states that"[a] long-term
drought, dating back to the 2019-2020 winter, continues across parts of the Pacific Northwest
(current hydroelectric generation is 25 percent lower than the 10-year average at the regional
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 6 JULY 22, 2024

level) and is picked up in the normalized hydroelectric generation forecast. Furthermore, the
removal of four Company-operated hydroelectric projects along the Klamath river contribute to
this decrease. These projects totaled approximately 180 MW of capacity and have ceased
generation." Please explain how the long-term drought is picked up in the normalized
hydroelectric generation forecast.
REQUEST NO. 107: The proposed NPC is based on the OFPC dated March 29, 2024.
Please respond to the following:
a. Please provide the latest OFPC;
b. Please explain when the OFPC is dated;
c. Please determine the new NPC based on the latest OFPC; and
d. Please update Mitchell's "ID_GRC_2025_2023 Normalized Load.xlsm" workpaper
based on the latest OFPC.
REQUEST NO. 108: Page 75 of Mitchell's Direct Testimony states that market
capacity limits are applied to all trading hubs. Please answer the following:
a. Please list market capacity limits for each trading hub and provide how the limits
were determined for each hub; and
b. Please provide specific historic evidence that outside sales transactions could not be
transacted at market prices due to unavailable buyers.
REQUEST NO. 109: Pages 34-35 of Mitchell's Direct Testimony shows coal prices for
Hunter's Bronco Utah Operations contract, Hunter's Wolverine Fuel Sales contract, and
Huntington's Wolverine Fuel Sales contract are high due to "Utah market supply shortages".
Please provide evidence that these contracts are prudent.
REQUEST NO. 110: Page 38 of Mitchell's Direct Testimony states that"Aurora can
receive more than one incremental price for the purpose of forecasting dispatch of coal-fired
resources and can recognize and optimize around volumetric constraints in each price tier."
Please respond to the following:
a. Please provide an example to illustrate tiered prices in Aurora;
b. Please explain how tiered prices affect dispatch of coal plants; and
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 7 JULY 22, 2024

c. Please explain the extent that the Company's coal contracts use tiered prices backed
up with evidence.
REQUEST NO. 111: Page 96 of Exhibit No. 48 in McCoy's Direct Testimony states
that the primary function of the EIM Board of State Regulators ("BOSR") is to provide a forum
for state regulators to learn about the EIM, EIM Governing Body, and related ISO developments.
Please explain how Idaho ratepayers benefit from this participation.
REQUEST NO. 112: Please respond to the following regarding Western Resource
Adequacy Program ("WRAP") fees:
a. How is the amount of the forecasted 2024 WRAP fees determined?
b. How is the amount of the 2023 WRAP fees determined?
c. Why do the fees decrease in 2024 compared to 2023?
d. Please explain when Idaho ratepayers will begin receiving benefits from the WRAP.
REQUEST NO. 113: Please respond to the following regarding Committee of State
Regulatory("COSR") materials fees, which according to Page 96 of Exhibit No. 48 are related to
the implementation of the WRAP program:
a. Please explain the difference between the WRAP fees and COSR materials fees;
b. Please explain why COSR materials fees are zero in 2023;
c. Please explain how the amount of COSR materials fees is determined in 2024; and
d. Please explain how and when Idaho ratepayers will begin receiving benefits from the
COSR.
REQUEST NO. 114: Please respond to the following regarding Wyoming Wind
Generation Tax as discussed on Page 38 of McCoy's Direct Testimony:
a. Please confirm that the excise tax is not levied for wind generation that is used to
meet native customer load; and
b. How does the Company determine that energy for sales or trade came from a
Wyoming wind facility and not another Company resource?
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 8 JULY 22, 2024

REQUEST NO. 115: Please provide the Excel version of Page 90 of Exhibit No. 48 of
McCoy's Direct Testimony.
REQUEST NO. 116: Please explain what types of costs are included on the allowance
line item in Exhibit No. 51 of McCoy's Direct Testimony. Specifically, are all the costs
associated with Washington CCA allowances?
REQUEST NO. 117: Please respond to the following regarding the cost of Washington
CCA allowances:
a. Please provide the cost of Washington CCA allowances at the Company level and for
the Idaho jurisdiction;
b. Please explain how the system and Idaho-allocated allowance costs are determined;
c. Please provide the workpapers that determine the system and Idaho-allocated
allowance costs; and
d. Please identify the specific tabs and line items that contain these allowance costs in
Excel file "ID GRC 2025 2023 Normalized Load.xlsm".
REQUEST NO. 118: Please provide a list of jurisdictions and rate cases in those
jurisdictions where the Company used the Aurora model, instead of other models such as GRID,
to determine NPC. Please provide the proposed amount of system NPC costs proposed in those
cases and the approved system NPC broken down by FERC account.
DATED at Boise, Idaho, this 22nd day of July 2024.
I'F . A4 Z A4
ak... .,- -
Adam Triplett
Deputy Attorney General
I:\Utility\UMISC\PRDREQ\PAC-E-24-04 PR#6.docx
SIXTH PRODUCTION REQUEST
TO ROCKY MOUNTAIN POWER 9 JULY 22, 2024

CERTIFICATE OF SERVICE
I HEREBY CERTIFY THAT I HAVE THIS 22ND DAY OF JULY 2024,
SERVED THE FOREGOING SIXTH PRODUCTION REQUEST OF THE
COMMISSION STAFF TO ROCKY MOUNTAIN POWER, IN CASE NO. PAC-E-24-
04, BY E-MAILING A COPY THEREOF, TO THE FOLLOWING:
MARK ALDER JOE DALLAS
ROCKY MOUNTAIN POWER CARLA SCARSELLA
1407 WEST NORTH TEMPLE STE 330 ROCKY MOUNTAIN POWER
SALT LAKE CITY UT 84116 825 NE Multnomah, Suite 2000
E-MAIL: mark.aldergpacificorp.com Portland, OR 97232
E-MAIL: joseph.dallas(aa pacificorp.com
carla.scarsellagpacificorp.com
DATA REQUEST RESPONSE CENTER
E-MAIL ONLY:
datarequestkpacificorp.com
ERIC L OLSEN LANCE KAUFMAN PhD
ECHO HAWK& OLSEN PLLC 2623 NW BLUEBELL PLACE
PO BOX 6119 CORVALLIS OR 97330
POCATELLO ID 83205 E-MAIL: lancegae isg insi hg t.com
E-MAIL: elogechohawk.com
MATTHEW NYKIEL BRAD HEUSINKVELD
ID CONSERVATION LEAGUE ID CONSERVATION LEAGUE
710 N 6TH STREET 710 N 6TH STREET
BOISE ID 83702 BOISE ID 83702
E-MAIL: matthew.n. kielggmail.com E-MAIL:
heusinkveld(ci),idahoconservation.org
THOMAS J BUDGE BRIAN C COLILINS
RACINE OLSON PLLP GREG MEYER
PO BOX 1391 BRUBAKER&ASSOCIATES
POCATELLO ID 83204-1391 16690 SWINGLEY RIDGE RD #140
E-MAIL: ti(�racineolson.com CHESTERFIELD MO 63017
E-MAIL: bcollinsgconsultbai.com
gmeyer(d),consultbai.com
Electronic Service Only: RONALD L WILLIAMS
KEVIN HIGGINS BRANDON HELGESON
NEAL TOWNSEND HAWLEY TROXELL ET AL
ENERGY STRATEGIES LLC 877 W MAIN ST
E-MAIL: khiggins(aenergystrat.com BOISE ID 83701
ntownsendgenergystrat.com E-MAIL: rwilliamsghawleytroxell.com
bhel eg son(a),hawleytroxell.com
CERTIFICATE OF SERVICE Page 1 of 2

Electronic Service Only: Electronic Service Only:
BRADLEY MULLINS VAL STEINER
MW ANALYTICS ITAFOS CONDA LLC
E-MAIL: brmullins(kmwanalytics.com E-MAIL: Val.steiner(o)itafos.com
Electronic Service Only:
KYLE WILLIAMS
BYU Idaho
E-MAIL: williamsk(a,byui.edu
KERI HAW AR, SECRETARY
CERTIFICATE OF SERVICE Page 2 of 2