20210914PAC to Staff Supplemental 140.pdf

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1407 W North Temple, Suite 330
Salt Lake City, Utah 84116
September 14,2021
Jan Noriyuki
Idaho Public Utilities Commission
472W. Washington
Boise, ID 83702-5918
ian.noriyuki@nuc. idaho. sov (C)
RE ID PAC.E.2I.O7
IPUC Set 5 (139-160)
Please find enclosed Rocky Mountain Power's ltt Supplemental Response to IPUC 5tr Set Data
Request 140. Also provided are Attachments IPUC 140 <l-2) I't Supplemental.
If you have any questions, please feel free to call me at [phone]
Sincerely,
-lsl-J. Ted Weston
Manager, Regulation
Enclosures
C.c.: Ronald L. Williams/PIIC [e-mail]
Bradley G. Mullins/PIIC [e-mail]
Adam Gardner/PIIC [e-mail] (W)
Kyle Williams/PIIC [e-mail] (W)
Val Steiner/PIIC [e-mail] (W)
Eric L. Olsen/IIPA [e-mail] (C)
Anthony Yankel/IIPA [e-mail] (C)
Randall C. Budge/Bayer randv@racineo lson. com (C)
Thomas J. Budge/Bayer tj @racineolson. com (WXC)
Brian C. Collins/Bayer bco I I ins@consultbai. com (WXC)
Maurice Brubaker/Bayer [e-mail] (C)
Kevin Higgins/Bayer kh i eeins@enereystrat. com (C)
Lance KaufmanlBayer lance@.aeeisinsieht.com (C)
James R. Smith/Bayer i im. r. sm i th@,ic loud.com (C)
Brad Purdy [e-mail] (C)
Ben Otto/lCL [e-mail] (C)
PAC-E-21-07 / Rocky Mountain Power
September 14,2021
IPUC Data Request 140 - I't Supplemental
IPUC Data Request 140
Please explain the Company's method and calculations for determining ldaho's
allocation of line losses in this case and for actual line losses in the Company's
most recent ECAM. Please explain how the line losses for electricity transmitted
through the state and consumed outside Idaho are excluded from ldaho's
allocation of line losses. Please include supporting work papers in electronic
format with formula intact.
I't Supplemental Response to IPUC Data Request 140
Further to the Company's response to IPUC Data Request 140 dated August 26,
2021, and the telephone conference held between representatives of Idaho Public
Utilities Commission (IPUC) staffand the Company held on September 10,2021,
the Company provides the following additional information:
Please refer to Attachment IPUC 140-l I't Supplemental which provides a real-
life example showing the math for the explanation provided in the Company's
original response to IPUC Data Request 140. Please refer to Attachment IPUC
140-2 l't Supplemental for a graphical example of the Idaho load calculation. The
following are defined terms from the Company's originalresponse to IPUC Data
Request 140:
Idaho's pro-rata share of load at input - this is the fraction of the total
PacifiCorp load that belongs to ldaho. Take the Idaho jurisdictional load and
divide it by the Total Company load to get that fraction.
State level system loads at input - these are the jurisdictional loads used to
calculate Idaho's pro-rata share.
Control area loads - this is the load at the control area level, used for balancing
the control area; the entire area where PacifiCorp has a responsibility to balance
the grid. For example, PacifiCorp has a responsibility to balance the load in the
city of Idaho Falls, but that is not PacifiCorp's retail load. This would be included
in the control area load.
Internal transmission lines - this is a tansmission line that is intemal to
PacifiCorp's control area. For example, a tansmission line between Utah and
Idaho, but within the control area would be an internal transmission line.
Interchange - In reference to IPUC Data Request 140, this is interchange with
other contol areas: a point at which confiol areas are physically connected. An
example of this would be the interchange between the ldaho Power Company
(PC) and PacifiCorp at American Falls.
PAC-E-2147 / Rocky Mountain Power
September 14,2021
IPUC Data Request 140 - l't Supplemental
Interchange point - interchange, but referencing a single point.
Borderline load - please refer to "foreign borderline customer load".
Interstate transfer - transmission lines that cross state boundaries.
Foreign borderline customer load - load that is not PacifiCorp's retail load
electrically inside the control area. This is removed from the confrol area load
when calculating the jurisdictional loads. An example of this is the Idaho Falls
borderline load. The city of Idaho Falls has its own service tenitory.
PacifiCorp borderline load - PacifiCorp retail load that is not electrically inside
a PacifiCorp control area. PacifiCorp does not have this scenario in Idaho. An
example would be PacifiCorp service tenitory within Western Area Power
Administration's (WAPA) confrol area in Wyoming.
Transfer losses - please refer to "third party contracfual transfer losses".
Third party contractual transfer losses - an entity compensating PacifiCorp for
using PacifiCorp's transmission system would return losses to PacifiCorp.An
example of this would be NV Energy moving power through PacifiCorp's system.
These losses are scheduled at the confrol area level and divided between the
jurisdictions based upon a pro-rata share of load at input.
Recordholder:Matt Hastings
To Be DeterminedSponsor: