20241121PAC to Staff 1-5.pdf

RECEIVED
Thursday, November 21, 2024
IDAHO PUBLIC
_ ROCKY MOUNTAIN UTILITIES COMMISSION
POWER
A DIVISION OF PACIFICORP
1407 W North Temple, Suite 330
Salt Lake City, Utah 84116
November 21, 2024
Monica Barrios-Sanchez
Commission Secretary
Idaho Public Utilities Commission
11331 W. Chinden Blvd.
Bldg. 8, Ste. 201-A
Boise, ID 83714
monica.barrio ssanchez(apuc.Idaho.gov
S ecretarygpuc.idaho.gov
RE: ID PAC-E-24-12
IPUC Set 1 (1-5)
Please find enclosed Rocky Mountain Power's Responses to IPUC 1st Set Data Requests 1-5.
If you have any questions, please feel free to call me at [phone].
Sincerely,
/s/
Mark Alder
Manager, Regulation
Enclosures

PAC-E-24-12/Rocky Mountain Power
November 21, 2024
IPUC Data Request 1
IPUC Data Request 1
On Page 2 of the Application, the Company states that the change between the
June 2024 load forecast and the May 2023 load forecast is "primarily due to
growth expectations for industrial and commercial customers in Utah and
Oregon."Please explain why the change starts after 2030, as shown in Figure No.
1. Additionally, given the fact that the May 2023 load forecast already considered
the commercial and industrial customers' increase as noted in the previous case
(Case No. PAC-E-23-20),please explain why the June 2024 load forecast has a
higher load than the May 2023 load forecast"primarily due to growth
expectations for industrial and commercial customers in Utah and Oregon".
Application at 2.
100,000
80,000 _ _ -P4-O-
3
� 60,000
LL 40,000
0
f Load Forecast-June 2024
J 20000 --0--Load Forecast-May 2023
0
< m o o a
ry ry ry ry ry ry ry ry ry ry ry ry ry ry ry ry ry ry ry ry
Figure No. 1: System Load Forecast Comparison
Response to IPUC Data Request 1
Relative to the May 2023 load forecast, the June 2024 forecast is lower over the
2024 through 2028 period due to a lower forecast for large customers. The
forecast is relatively similar over the 2029 through 2030 period, while from 2031
and on the forecast is higher due to a higher forecast for large customers.
Recordholder: Lee Elder
Sponsor: Lee Elder

PAC-E-24-12/Rocky Mountain Power
November 21, 2024
IPUC Data Request 2
IPUC Data Request 2
Please explain why the 2024 load forecast for Idaho is consistently lower than the
2023 load forecast for Idaho throughout the entire forecast period from 2024
through 2043, as shown in Figure No. 2.
4,000
o-o-o-o-a.a
3,900
a _
3,800
v
0
LL 3,700
m
0
J f Load Forecast-June 2024 in Idaho
3,600
--0--Load Forecast-May 2023 in Idaho
3,500
a u o m m o N N m v u o n m am o ti N m
N N N N N N M M M M (n M M M M rn a v v a
O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N
Figure No.2: Comparison of Load Forecast in Idaho
Response to IPUC Data Request 2
The 2024 load forecast for Idaho is lower than the 2023 load forecast for Idaho
primarily due to a lower industrial class forecast.
Recordholder: Lee Elder
Sponsor: Lee Elder

PAC-E-24-12/Rocky Mountain Power
November 21, 2024
IPUC Data Request 3
IPUC Data Request 3
Please explain why the "Load Forecast—June 2024" in the Figure No. 3 is lower
than the "Draft 2025 IRP Load Forecast"presented in the 2025 Integrated
Resource Plan (IRP) Public Input Meeting on June 26-27, 2024, as shown in
Figure No. 3.
Load Forecast
120,00D
100,000
80,000 —
60,000
40,000
20,000 I I I I I I I I I I I I I I I I
0
2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044
Load Forecast-June 2024
�Drah 2025 IRP t dFo—st �20231Rp UpMe �20231Rp
Figure No.3: Comparison of Load Forecast between June 2024 Forecast to 2025 IRP Load
Forecast(draft)
Response to IPUC Data Request 3
The draft 2025 Integrated Resource Plan (IRP) load forecast is the load forecast
prior to accounting for demand-side management (DSM) impacts to load. The
integrated resource planning team requires a load forecast that does not account
for DSM impacts to load so that cost effective DSM selections can be made in the
planning process.
The "Load Forecast—June 2024"in the Figure No. 3 is lower than the draft 2025
IRP load forecast because the "Load Forecast—June 2024" accounts for the
Company's current expectation of DSM impacts to load.
Recordholder: Lee Elder
Sponsor: Lee Elder

PAC-E-24-12/Rocky Mountain Power
November 21, 2024
IPUC Data Request 4
IPUC Data Request 4
Please explain why the 2024 gas forecast for Henry Hub proposed in this case is
lower than the 2023 gas forecast approved in Case No. PAC-E-23-20 in the near
term, as shown below. Also, please explain why the 2024 gas forecast proposed in
this case is approximately the same as the 2023 gas forecast starting in 2029.
Gas Forecast for Henry Hub
10
9
8
7
6
5
4
3
2
1
0
01y 01�P1 ti ti 010 01l OHO Off~Off~03�Oda O�y 'L Off~'Y 1P'LOa9
ti ti ti ti ti ti ti 1 ti ti ti ti 1 'L
-2024 Gas Forecast for Henry Hub -2023 Gas Forecast for Henry Hub
Response to IPUC Data Request 4
The Company's official forward price curve (OFPC) consists of the following for
both electricity and natural gas prices:
- Months 1-36 (years one through three): based on current market forwards,
prices currently being offered in the market for delivery in future periods.
- Months 37-48 (year four): this is referred to as the blending period, and
reflects an average of the monthly values for year three and year five.
- Months 49+ (year five and beyond): prices provided by the Company's
consultant, Siemens, based on a fundamentals-based model of supply and
demand. Siemens produces a full co-optimized electricity and gas forecast
twice each year(March and September), with limited updates and
modifications in the other two quarters.
The Company has not identified particular drivers for the lower prices in the
current forecast, as both values reflect near term market prices at the time they
were prepared. In general, forward market prices reflect market participant's
perceived balance between the risk of spot market prices being higher than
expected and the risk of spot prices being lower than expected. While market
prices represent a consensus between buyers and sellers, those entities need not
agree on the underlying basis for the pricing results. The Company would note
that natural gas prices were relatively high during 2022 and in the first part of
2023, and this may have influenced forward expectations. A perceived risk of
possibly over-supply in natural gas (whether due to excess production or limited
demand) could lead to lower prices.

PAC-E-24-12/Rocky Mountain Power
November 21, 2024
IPUC Data Request 4
Similarly, the Company has not identified particular drivers for the change, or
lack thereof, in the Siemens forecasts applicable in 2029 and beyond.
Recordholder: Dan MacNeil
Sponsor: Dan MacNeil

PAC-E-24-12/Rocky Mountain Power
November 21, 2024
IPUC Data Request 5
IPUC Data Request 5
Please explain whether monthly Official Forward Price Curve (OFPC) is used in
the IRP model to determine IRP-based avoided cost rates. If hourly OFPC is used,
please explain how monthly OFPC is converted to hourly OFPC.
Response to IPUC Data Request 5
Shaped hourly prices are used to determine avoided cost rates. Monthly official
forward price curve prices (OFPC) are shaped into hourly prices using hourly
scalars and monthly scalars. There are three sets of 24-hour hourly scalars per
month for PacifiCorp West (PACW) and PacifiCorp East (PACE). The three
scalars are Monday through Friday, Saturday, and Sunday/North American
Electric Reliability Corporation (NERC)holidays. The hourly scalars are
calculated using the most recent 24 months of California Independent System
Operator(CAISO) day-ahead hourly prices for Malin (for PACW) and Palo
Verde (PV) (for PACE). The scalars are calculated as the average price of the
hour in the 24-month dataset divided by the average price of the hours for the
heavy load hours (HLH) or light load hours (LLH) time periods in the 24-month
dataset.
Recordholder: Dan MacNeil/Elaine Biggs
Sponsor: Dan MacNeil