20220811Quarterly Report.pdf

LISA O’HARA
Corporate Counsel
lo’[e-mail]
August 11, 2022
Ms. Jan Noriyuki
Secretary
Idaho Public Utilities Commission
PO Box 83720
Boise, ID 83720-0074
Re: Case No. IPC-E-16-19
Deferral and Recovery of Costs Associated with Participation in Energy Imbalance
Market – California Independent System Operator (“CAISO”) Quarterly Energy
Imbalance Market (“EIM”) Benefits Assessment Report
Dear Ms. Noriyuki:
Pursuant to Order No. 33706 issued in Case No. IPC-E-16-19, Idaho Power Company
(“Idaho Power” or “Company”) hereby submits the quarterly CAISO Western EIM Benefits Report
(“Report”) for the second quarter of 2022. The Report presents CAISO’s quantification of benefits
associated with participation in the Western EIM. For the first quarter of 2022, CAISO estimated
Western EIM gross benefits of $8.44 million for Idaho Power.
The EIM has provided financial benefits to the Company, and ultimately its customers.
However, as discussed in Idaho Power’s prior quarterly compliance filings as well as the
Company’s May 24, 2019, Report of EIM Benefits and Costs of Participation, CAISO’s calculation
of benefits for Idaho Power is overstated due to several of the modeling assumptions used in its
benefit calculation. The Company developed a more precise methodology, that uses inputs
specific to Idaho Power, for determining actual EIM benefits, the details of which are discussed in
the Company’s May 24, 2019, Report of EIM Benefits and Costs of Participation.
If you have any questions regarding this report, please contact Matt Larkin, Revenue
Requirement Senior Manager, at [phone] or [e-mail].
Sincerely,
Lisa J. O’Hara
Enclosure
RECEIVED
2022 AUG 11 PM 4:52
IDAHO PUBLIC
UTILITIES COMMISSION

WESTERN ENERGY IMBALANCE
MARKET BENEFITS
Second Quarter 2022

Prepared by: Market Analysis and Forecasting

July 29, 2022
WEIM BENEFITS REPORT SECOND QUARTER 2022

MPP/MA&F Copyright 2022 California ISO Page 2 of 36

CONTENTS

EXECUTIVE SUMMARY ......................................................................................................... 3
BACKGROUND ...................................................................................................................... 4
WEIM ECONOMIC BENEFITS IN Q2 2022 ............................................................................. 4
CUMULATIVE ECONOMIC BENEFITS SINCE INCEPTION.......................................................... 5
INTER-REGIONAL TRANSFERS ............................................................................................. 6
WHEEL-THROUGH TRANSFERS ...........................................................................................21
REDUCED RENEWABLE CURTAILMENT AND GHG REDUCTIONS .................................. 28
FLEXIBLE RAMPING PROCUREMENT DIVERSITY SAVINGS ............................................ 29
CONCLUSION ...................................................................................................................... 34
APPENDIX 1: GLOSSARY OF ABBREVIATIONS ................................................................ 36
WEIM BENEFITS REPORT SECOND QUARTER 2022

MPP/MA&F Copyright 2022 California ISO Page 3 of 36

EXECUTIVE SUMMARY
This report presents the benefits associated with
participation in the Western Energy Imbalance Market
(WEIM).
The measured benefits of participation in the WEIM
include cost savings, increased integration of
renewable energy, and improved operational
efficiencies including the reduction of
the need for real-time flexible reserves.
This analysis demonstrates the benefit of economic
dispatch in the real time market across a larger WEIM
footprint with diverse resources and geography.
Q2 2022 Gross Benefits by Participant
(millions $)
Arizona Public Service $10.14
Avista $5.16
BANC $68.09
BPA $4.36
California ISO $71.75
Idaho Power $8.44
LADWP $13.78
NV Energy $8.63
NorthWestern Energy $5.90
PacifiCorp $35.21
Portland General Electric $11.92
PNM $3.10
Puget Sound Energy $4.90
Powerex $4.66
Seattle City Light $2.90
Salt River Project $21.26
Tacoma Power $1.55
TEP $2.84
TID $2.85
Total $287.44

Gross benefits from WEIM since November 2014
$2.39 billion
ECONOMICAL
$287.44 M
Gross benefits realized due to more
efficient inter-and intra-regional
dispatch in the Fifteen-Minute
Market (FMM) and Real-Time
Dispatch (RTD)*

ENVIRONMENTAL
50,655
Metric tons of CO2** avoided
curtailments

OPERATIONAL
54%
Average reduction in flexibility
reserves across the footprint
2022
Q2 BENEFITS
WEIM BENEFITS REPORT SECOND QUARTER 2022

MPP/MA&F Copyright 2022 California ISO Page 4 of 36

*WEIM Quarterly Benefit Report Methodology: https://www.westerneim.com/Documents/EIM-BenefitMethodology.pdf.
**The GHG emission reduction reported is associated with the avoided curtailment only. The current market process and
counterfactual methodology cannot differentiate the GHG emissions resulting from serving ISO load via the EIM versus dispatch that
would have occurred external to the ISO without the WEIM. For more details, see
http://www.caiso.com/Documents/GreenhouseGasEmissionsTrackingReport-FrequentlyAskedQuestions.pdf
BACKGROUND
The Western EIM began financially binding operation on November 1, 2014 by optimizing
resources across the ISO and PacifiCorp Balancing Authority Areas (BAAs). NV Energy began
participating in December 2015, Arizona Public Service and Puget Sound Energy began
participating in October 2016, and Portland General Electric began participating in October
2017. Idaho Power and Powerex began participating in April 2018, and the Balancing Authority
of Northern California (BANC) began participating in April 2019. Seattle City Light and Salt River
Project began participating in April 2020.
In 2021, new balancing authorities began participating in the Western EIM, with the Turlock
Irrigation District (TID) in March 2021, the second phase of BANC in March 2021, and the Los
Angeles Department of Water and Power (LADWP) and Public Service Company of New
Mexico (PNM) in April 2021, followed by NorthWestern Energy (NWMT) starting in June 2021.
Avista Utilities (AVA) and Tacoma Power (TPWR), two utilities serving a combined 600,000
electric customers in the Pacific Northwest, became the newest members of the WEIM, with
both beginning their participation on March 2, 2022. On May 3, 2022, the Bonneville Power
Administration (BPA) and Tucson Electric Power (TEP) both Joined the WEIM.
The Western EIM footprint now includes portions of Arizona, California, Idaho, Montana,
Nevada, New Mexico, Oregon, Utah, Washington, Wyoming, and extends to the border with
Canada.
WEIM ECONOMIC BENEFITS IN Q2 2022
Table 1 shows the estimated WEIM gross benefits by each region per month1. The monthly
savings presented show $93.66 million for April, $83.84 million for May, and $109.94 million for
June with a total estimated benefit of $287.44 million for this quarter2. This level of WEIM
benefits accrued from having additional WEIM areas participating in the market and economical
transfers displacing more expensive generation.

1 The WEIM benefits reported here are calculated based on available data. Intervals without complete data are
excluded in the calculation. The intervals excluded due to unavailable data are normally within a few percent
points of the total intervals. 2 For several quarterly estimates, CAISO benefits were calculated on a variation of the counterfactual
methodology. For CAISO only the logic had considered offline resources as part of the bid stack in the
counterfactual. In Q4 2021, CAISO identified some questionable results that drove persistent negative be nefits
for CAISO when considering offline resources. Since Q4 2021, the benefit calculation for CAISO area follows
the same methodology applicable to all WEIM entities in which only online resources are used.
WEIM BENEFITS REPORT SECOND QUARTER 2022

MPP/MA&F Copyright 2022 California ISO Page 5 of 36
Region April May June Total
APS $3.69 $3.83 $2.62 $10.14
AVA $1.98 $1.72 $1.46 $5.16
BANC $4.71 $13.78 $49.60 $68.09
BPA $2.26 $2.10 $4.36
CISO $42.10 $14.56 $15.09 $71.75
IPCO $3.89 $2.78 $1.77 $8.44
LADWP $4.42 $5.30 $4.06 $13.78
NVE $2.49 $2.40 $3.74 $8.63
NWMT $2.50 $2.44 $0.96 $5.90
PAC $13.35 $15.43 $6.43 $35.21
PGE $3.60 $3.43 $4.89 $11.92
PNM $0.07 $1.26 $1.77 $3.10
PSE $1.79 $1.94 $1.17 $4.90
PWRX $0.64 $2.05 $1.97 $4.66
SCL $1.10 $1.00 $0.80 $2.90
SRP $5.95 $7.04 $8.27 $21.26
TPWR $0.40 $0.43 $0.72 $1.55
TEP $1.29 $1.55 $2.84
TID $0.98 $0.90 $0.97 $2.85
Total $93.66 $83.84 $109.94 $287.44
TABLE 1: Q2 2022 benefits in millions USD
CUMULATIVE ECONOMIC BENEFITS SINCE INCEPTION
Since the start of the WEIM in November 2014, the cumulative economic benefits of the market
have totaled $2.39 billion. The quarterly benefits have grown over time as a result of the
participation of new BAAs, which results in benefits for both the individual BAA but also
compounds the benefits to adjacent BAAs through additional transfers. The ISO began
publishing quarterly WEIM benefit reports in April 2015.3
Graph 1 illustrates the gross economic benefits of the WEIM by quarter for each participating
BAA.

3 Prior reports are available at https://www.westerneim.com/Pages/About/QuarterlyBenefits.aspx
WEIM BENEFITS REPORT SECOND QUARTER 2022

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GRAPH 1: Cumulative economic benefits for each quarter by BAA
INTER-REGIONAL TRANSFERS
A significant contributor to EIM benefits is transfers across balancing areas, providing access to
lower cost supply, while factoring in the cost of compliance with greenhouse gas (GHG)
emissions regulations when energy is transferred into the ISO. As such, the transfer volumes
are a good indicator of a portion of the benefits attributed to the WEIM. Transfers can take place
in both the 15-Minute Market and Real-Time Dispatch (RTD).
Generally, transfer limits are based on transmission and interchange rights that participating
balancing authority areas make available to the WEIM, with the exception of the PacifiCorp
West (PACW) -ISO transfer limit and the Portland General Electric (PGE) -ISO transfer limit in
RTD. These RTD transfer capacities between PACW/PGE and the ISO are determined based
on the allocated dynamic transfer capability driven by system operating conditions. This report
does not quantify a BAA’s opportunity cost that the utility considered when using its transfer
rights for the EIM.
Table 2 provides the 15-minute and 5-minute WEIM transfer volumes with base schedule
transfers excluded. The WEIM entities submit inter-BAA transfers in their base schedules. The
benefits quantified in this report are only attributable to the transfers that occurred through the
WEIM. The benefits do not include any transfers attributed to transfers submitted in the base
schedules that are scheduled prior to the start of the EIM.
The transfer from BAA_x to BAA_y and the transfer from BAA_y to BAA_x are separately
reported. For example, if there is a 100 Megawatt-Hour (MWh) transfer during a 5-minute
interval, in addition to a base transfer from ISO to NVE, it will be reported as 100 MWh
WEIM BENEFITS REPORT SECOND QUARTER 2022

MPP/MA&F Copyright 2022 California ISO Page 7 of 36
from_BAA ISO to_BAA NEVP, and 0 MWh from_BAA NEVP to_BAA ISO in the opposite
direction. The 15-minute transfer volume is the result of optimization in the 15-minute market
using all bids and base schedules submitted into the WEIM. The 5-minute transfer volume is the
result of optimization using all bids and base schedules submitted into WEIM, based on unit
commitments determined in the 15-minute market optimization. The maximum transfer
capacities between WEIM entities are shown in Graph 2 below.

Month

From BAA

To BAA
15min WEIM transfer
(15m – base)
5min WEIM transfer
(5m – base)
AVA CISO 0 0
April AVA IPCO 20,394 16,524
AVA NWMT 6,205 5,541
AVA PACW 10,480 12,791
AVA PGE 48 62
AVA PSEI 0 1
AVA SCL 2 1
AVA TPWR 2,909 3,389
AZPS CISO 106,535 70,984
AZPS LADWP 6,478 7,404
AZPS NEVP 8,905 16,269
AZPS PACE 31,007 36,001
AZPS PNM 18,144 15,167
AZPS SRP 44,298 47,638
BANC CISO 7,941 3,264
BANC TIDC 30 145
CISO AVA 87 20
CISO AZPS 69,708 73,122
CISO BANC 85,021 100,826
CISO LADWP 76,743 80,241
CISO NEVP 73,631 78,704
CISO PACW 0 8,331
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CISO PGE 11,468 15,791
CISO PWRX 41,738 50,391
CISO SRP 173,251 176,313
CISO TIDC 11,060 12,811
IPCO AVA 27,722 33,028
IPCO NEVP 45,717 33,915
IPCO NWMT 2,648 3,081
IPCO PACE 19,505 14,309
IPCO PACW 30,365 40,626
IPCO PSEI 0 0
IPCO SCL 9,280 10,695
LADWP AZPS 2,428 3,116
LADWP CISO 92,685 66,908
LADWP NEVP 11,999 16,419

LADWP PACE 34,565 37,081
NEVP AZPS 3,021 3,101
NEVP CISO 75,594 53,435
NEVP IPCO 34,940 45,747
NEVP LADWP 19,953 23,871
NEVP PACE 10,672 12,977
NWMT AVA 21,314 26,256
NWMT IPCO 3,773 4,108
NWMT PACE 8,283 5,869
NWMT PACW 0 4
NWMT PGE 10 29
NWMT PSEI 20 33
NWMT TPWR 3,119 3,684
PACE AZPS 163,693 150,630
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PACE IPCO 51,491 64,637
PACE LADWP 84,511 69,606
PACE NEVP 23,563 20,808
PACE NWMT 24,092 27,565
PACE PACW 32,675 41,067
PACE SRP 0 0
PACW AVA 8,656 9,452
PACW CISO 60,528 80,218
PACW IPCO 21,181 14,035
PACW NWMT 5 5
PACW PGE 39,297 45,740
PACW PSEI 30,125 32,468
PACW SCL 998 972
PGE AVA 0 61
April PGE CISO 30,727 29,991
PGE NWMT 34 29
PGE PACW 21,307 24,282
PGE PSEI 0 0
PGE SCL 1,067 996
PGE TPWR 2,843 2,905
PNM AZPS 28,441 36,596
PNM SRP 15,061 16,969
PSEI AVA 0 1
PSEI IPCO 0 0
PSEI NWMT 8 33
PSEI PACW 34,478 37,186
PSEI PGE 0 0
PSEI PWRX 5,578 6,972
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PSEI SCL 12,480 11,398
PSEI TPWR 5,344 5,461
PWRX CISO 0 0
PWRX PSEI 21,825 21,249
SCL AVA 1 1
SCL IPCO 1,474 1,341
SCL PACW 920 1,112
SCL PGE 1,374 1,607
SCL PSEI 12,048 16,353
SRP AZPS 4,575 6,585
SRP CISO 49,283 40,892
SRP PACE 0 0
SRP PNM 1,580 1,225
TIDC BANC 74 148
TIDC CISO 14,826 12,010
TPWR AVA 2,038 1,631
TPWR NWMT 1,796 1,493
TPWR PGE 3,053 3,061
TPWR PSEI 10,632 10,722
May AVA BPAT 4,997 3,193
AVA CISO 321 320
AVA IPCO 12,634 12,924
AVA NWMT 20,196 14,720
AVA PACW 7,459 9,702
AVA PGE 0 27
AVA PSEI 0 0
AVA SCL 8 3
AVA TPWR 1,915 1,951
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AZPS CISO 56,237 34,273
AZPS LADWP 526 1,364
May AZPS NEVP 1,175 2,596
AZPS PACE 29,605 38,059
AZPS PNM 42,248 34,449
AZPS SRP 94,492 90,578
AZPS TEPC 11,098 11,526
BANC BPAT 1,112 1,264
BANC CISO 7,397 6,010
BANC TIDC 33 76
BPAT AVA 3,264 2,655
BPAT BANC 45 171
BPAT CISO 9,105 13,408
BPAT IPCO 1,277 1,325
BPAT LADWP 1,928 818
BPAT NEVP 389 220
BPAT NWMT 8,458 4,973
BPAT PACW 3,747 1,938
BPAT PGE 15,217 10,544
BPAT PSEI 13,355 15,088
BPAT PWRX 13,404 2,790
BPAT SCL 964 1,242
BPAT TPWR 4,105 4,675
CISO AVA 0 0
CISO AZPS 108,931 119,324
CISO BANC 140,055 144,032
CISO BPAT 5,329 9,780
CISO LADWP 65,629 76,466
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CISO NEVP 114,631 142,138
May CISO PACW 898 13,245
CISO PGE 13,869 35,171
CISO PWRX 103,222 116,329
CISO SRP 233,061 251,791
CISO TEPC 3,935 3,799
CISO TIDC 16,133 16,403
IPCO AVA 22,176 25,776
IPCO BPAT 4,252 1,603
IPCO NEVP 4,572 2,682
IPCO NWMT 4,814 5,912
IPCO PACE 62,009 39,574
IPCO PACW 27,098 32,785
IPCO PSEI 0 0
IPCO SCL 8,334 9,465
LADWP AZPS 2,322 3,093
LADWP BPAT 1,735 800
LADWP CISO 71,092 50,524
LADWP NEVP 15,764 21,057
LADWP PACE 28,235 32,900
LADWP TEPC 0 83
NEVP AZPS 9,672 8,583
NEVP BPAT 743 502
NEVP CISO 100,199 65,338
NEVP IPCO 18,269 20,665
NEVP LADWP 24,255 27,189
NEVP PACE 62,305 75,527
NWMT AVA 13,111 16,444
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NWMT BPAT 8,236 5,871
May NWMT IPCO 2,319 3,858
NWMT PACE 18,733 13,988
NWMT PACW 0 1
NWMT PGE 31 16
NWMT PSEI 43 7
NWMT TPWR 1,679 2,136
PACE AZPS 188,726 166,512
PACE IPCO 59,360 86,462
PACE LADWP 107,420 95,825
PACE NEVP 95,324 73,337
PACE NWMT 24,644 28,147
PACE PACW 17,234 21,078
PACE SRP 0 0

PACE TEPC 2,868 1,649
PACW AVA 10,429 11,849
PACW BPAT 6,114 8,427
PACW CISO 40,522 74,582
PACW IPCO 41,422 36,860
PACW NWMT 1 1
PACW PGE 61,168 52,085
PACW PSEI 23,739 24,918
May PACW SCL 1,476 1,513
PGE AVA 24 28
PGE BPAT 10,097 9,760
PGE CISO 25,689 23,700
PGE NWMT 38 12
PGE PACW 18,473 26,855
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PGE PSEI 0 2
PGE SCL 1,396 1,621
PGE TPWR 5,783 7,298
PNM AZPS 7,443 9,283
PNM SRP 3,717 3,799
PNM TEPC 19,551 19,898
PSEI AVA 0 0
PSEI BPAT 23,116 24,524
PSEI IPCO 0 0
PSEI NWMT 14 3
PSEI PACW 13,399 14,445
PSEI PGE 0 2
May PSEI PWRX 19,784 20,398
PSEI SCL 7,287 7,266
PSEI TPWR 5,988 6,051
PWRX BPAT 3,143 2,461
PWRX CISO 0 0
PWRX PSEI 9,627 9,607
SCL AVA 4 2
SCL BPAT 1,583 1,514
SCL IPCO 6,414 6,157
SCL PACW 502 652
SCL PGE 1,001 1,031
SCL PSEI 10,783 13,798
SRP AZPS 8,960 13,548
SRP CISO 35,923 32,898
SRP PACE 0 0
SRP PNM 777 1,096
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SRP TEPC 80,131 91,726
May TEPC AZPS 250 72
TEPC CISO 13,630 2,924
TEPC LADWP 0 0
TEPC PACE 158 225
TEPC PNM 8,882 6,798
TEPC SRP 8,763 17,041
TIDC BANC 148 226
TIDC CISO 7,454 6,662
TPWR AVA 991 1,194
TPWR BPAT 5,938 5,746
TPWR NWMT 594 371
TPWR PGE 3,586 2,963
TPWR PSEI 6,116 7,682
June AVA BPAT 5,697 406
AVA CISO 0 0
AVA IPCO 19,387 9,691
AVA NWMT 8,671 8,888
AVA PACW 4,100 2,252
AVA PGE 0 0
AVA PSEI 0 0
AVA SCL 7 0
AVA TPWR 0 0
AZPS CISO 62,964 27,082
AZPS LADWP 20,883 18,279
AZPS NEVP 8,203 9,826
AZPS PACE 78,792 95,501
AZPS PNM 28,526 29,050
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AZPS SRP 30,063 17,897
June AZPS TEPC 26,059 23,874
BANC BPAT 2,035 0
BANC CISO 6,626 9,577
BANC TIDC 161 309
BPAT AVA 5,927 3,735
BPAT BANC 136 0
BPAT CISO 970 2,042
BPAT IPCO 1,597 31
BPAT LADWP 2,748 0
BPAT NEVP 267 0
BPAT NWMT 25,521 3,725
BPAT PACW 9,990 3,840
BPAT PGE 26,200 16,429
BPAT PSEI 28,247 28,987
BPAT PWRX 13,371 0
BPAT SCL 5,389 4,838
BPAT TPWR 11,342 9,848
CISO AVA 0 0
CISO AZPS 95,766 117,824
CISO BANC 189,226 186,320
CISO BPAT 862 1,968
CISO LADWP 92,507 120,240
CISO NEVP 114,963 134,766
CISO PACW 5,909 48,873
CISO PGE 22,744 62,760
CISO PWRX 63,709 83,326
CISO SRP 205,170 240,137
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CISO TEPC 2,011 2,538
June CISO TIDC 9,640 9,452
IPCO AVA 21,875 23,515
IPCO BPAT 1,411 0
IPCO NEVP 23,059 11,967
IPCO NWMT 4,394 7,790
IPCO PACE 25,922 15,769
IPCO PACW 37,118 19,512
IPCO PSEI 0 0
IPCO SCL 7,773 10,522
LADWP AZPS 3,850 5,604
LADWP BPAT 5,096 0
LADWP CISO 14,438 6,421
LADWP NEVP 13,680 17,035

LADWP PACE 13,217 12,022
LADWP TEPC 0 0
NEVP AZPS 6,668 7,636
NEVP BPAT 1,347 0
NEVP CISO 43,430 10,628
NEVP IPCO 70,804 77,974
NEVP LADWP 39,289 34,228
NEVP PACE 43,582 47,042
NWMT AVA 21,277 19,088
NWMT BPAT 6,028 625
NWMT IPCO 3,571 2,858
NWMT PACE 5,959 2,625
NWMT PACW 282 0
NWMT PGE 174 0
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NWMT PSEI 77 0
NWMT TPWR 1,229 2,492
June PACE AZPS 74,780 55,992
PACE IPCO 57,496 62,736
PACE LADWP 49,749 51,623
PACE NEVP 39,964 22,428
PACE NWMT 30,729 27,130
PACE PACW 51,580 40,357
PACE SRP 0 0
PACE TEPC 1,536 1,103
PACW AVA 15,528 16,880
PACW BPAT 4,176 656
PACW CISO 7,124 21,286
PACW IPCO 14,579 13,248
PACW NWMT 0 0
PACW PGE 54,893 47,383
PACW PSEI 22,296 29,307
PACW SCL 1,680 2,024
PGE AVA 0 0
June PGE BPAT 9,824 14,726
PGE CISO 9,436 5,703
PGE NWMT 108 0
PGE PACW 19,654 18,578
PGE PSEI 3 0
PGE SCL 1,469 1,868
PGE TPWR 1,339 2,453
PNM AZPS 24,924 25,722
PNM SRP 4,149 2,826
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PNM TEPC 25,169 24,931
June PSEI AVA 0 0
PSEI BPAT 9,819 13,642
PSEI IPCO 0 0
PSEI NWMT 17 0
PSEI PACW 11 0
PSEI PGE 1 0
PSEI PWRX 15,518 16,414
PSEI SCL 20,565 17,180
PSEI TPWR 6,136 6,662
PWRX BPAT 4,255 34
PWRX CISO 0 0
PWRX PSEI 12,295 12,347
SCL AVA 17 0
SCL BPAT 118 46
SCL IPCO 9,305 6,415
SCL PACW 1,098 798
SCL PGE 1,170 867
SCL PSEI 3,912 6,684
SRP AZPS 15,979 19,695
SRP CISO 50,824 38,195
SRP PACE 0 0
SRP PNM 947 1,651
SRP TEPC 65,964 77,789
TEPC AZPS 399 0
TEPC CISO 16,959 10,582
TEPC LADWP 0 0
TEPC PACE 864 1,578
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TABLE 2: Energy transfers (MWh) in the FMM and RTD markets for Q2 2022

TEPC PNM 17,131 13,585
June TEPC SRP 12,777 10,796
TIDC BANC 203 0
TIDC CISO 12,951 14,046
TPWR AVA 0 0
TPWR BPAT 1,275 2,462
TPWR NWMT 2,957 1,689
TPWR PGE 2,372 1,449
TPWR PSEI 7,000 9,278
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GRAPH 2: Estimated maximum transfer capacity
WHEEL-THROUGH TRANSFERS
As the footprint of the WEIM grows, wheel-through transfers may become more common. In
order to derive the wheel-through transfers for each WEIM BAA, the ISO uses the following
calculation for every real-time interval dispatch:

 Total import: summation of transfers above base transfers coming into the WEIM
BAA under analysis
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 Total export: summation of all transfers above base transfers going out of the WEIM
BAA under analysis
 Net import: the maximum of zero or the difference between total imports and total
exports
 Net export: the maximum of zero or the difference between total exports and total
imports
 Wheel-through: the minimum of the WEIM transfers into (total import) or WEIM
transfer out (total export) of a BAA for a given interval

All wheel-through transfers are summed over both the month and the quarter.

Currently, a WEIM entity facilitating a wheel through receives no direct financial benefit for
facilitating the wheel; only the sink and source directly benefit. As part of the WEIM
Consolidated Initiatives stakeholder process, the ISO committed to monitoring the wheel
through volumes to assess whether, after the addition of new WEIM entities, there is a potential
future need to pursue a market solution to address the equitable sharing of wheeling benefits.

The ISO will continue to track the volume of wheel-through transfers in the WEIM market in the
quarterly reports.

This volume reflects the total wheel-through transfers for each WEIM BAA, regardless of the
potential paths used to wheel through. The net imports and exports estimated in this section
reflect the overall volume of net imports and exports; in contrast, the imports and exports
provided in Table 2 reflect the gross transfers between two WEIM BAAs.

The metric is measured as energy in MWh for each month and the corresponding calendar
quarter, as shown in Tables 3 through 6 and Graphs 3 through 6.

BAA Net Export Net Import Wheel Through
AVA

62,566

151,797

39,821
AZPS

127,260

325,482

500,557
BANC

19,328

430,405

1,317
BPAT

93,752

70,440

39,571
CISO

2,160,868

441,541

372,362
IPCO

118,497

263,568

224,029
LADWP

84,341

418,433

188,721
NEVP

183,385

273,110

331,057
NWMT

40,364

71,478

69,628
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PACE

824,667

198,626

284,023
PACW

248,054

142,851

277,458
PGE

88,154

214,303

82,713
PNM

113,932

76,929

26,093
PSEI

79,693

130,587

107,944
PWRX

16,732

267,654

28,967
SCL

32,420

55,646

25,956
SRP

169,868

720,349

155,433
TEPC

58,079

253,395

5,521
TIDC

32,509

38,613

583
TPWR

19,923

29,186

29,818

TABLE 3: Estimated wheel-through transfers in Q2 2022

GRAPH 3: Estimated wheel-through transfers in Q1 2022

BAA Net Export Net Import Wheel Through
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AVA

22,848

54,990

15,462
AZPS

30,459

110,147

163,004
BANC

3,272

100,837

137
CISO

494,339

255,490

102,212
IPCO

46,954

57,693

88,700
LADWP

41,281

98,879

82,243
NEVP

55,128

82,111

84,004
NWMT

17,552

15,316

22,431
PACE

294,558

27,639

79,755
PACW

72,220

53,570

111,828
PGE

41,277

49,303

16,987
PNM

52,128

14,956

1,436
PSEI

29,559

49,335

31,492
PWRX

10,937

47,051

10,312
SCL

13,337

16,984

7,077
SRP

45,994

238,211

2,708
TIDC

12,011

12,809

147
TPWR

8,702

7,234

8,205

TABLE 4: Estimated wheel-through transfers in April 2022

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GRAPH 4: Estimated wheel-through transfers in April 2022

BAA Net Export Net Import Wheel Through
AVA

29,449

44,558

13,391
AZPS

20,765

128,333

192,081
BANC

6,170

143,248

1,180
BPAT

32,468

48,067

27,379
CISO

769,360

151,522

159,118
IPCO

47,285

97,739

70,512
LADWP

25,667

118,873

82,789
NEVP

59,358

103,585

138,445
NWMT

13,868

25,684

28,454
PACE

332,732

60,441

140,277
PACW

114,734

24,756

95,945
PGE

36,218

68,781

33,058
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PNM

21,064

30,427

11,916
PSEI

37,049

35,461

35,640
PWRX

2,802

130,251

9,266
SCL

14,237

12,194

8,916
SRP

45,112

269,052

94,156
TEPC

22,104

123,726

4,955
TIDC

6,752

16,343

135
TPWR

5,415

9,570

12,541

TABLE 5: Estimated wheel-through transfers in May 2022

GRAPH 5: Estimated wheel-through transfers in May 2022

BAA Net Export Net Import Wheel Through
AVA

10,269

52,249

10,968
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AZPS

76,036

87,001

145,473
BANC

9,886

186,320

-
BPAT

61,283

22,373

12,192
CISO

897,170

34,529

111,033
IPCO

24,257

108,136

64,817
LADWP

17,394

200,681

23,689
NEVP

68,899

87,414

108,608
NWMT

8,944

30,478

18,743
PACE

197,378

110,546

63,991
PACW

61,100

64,525

69,685
PGE

10,660

96,220

32,669
PNM

40,739

31,545

12,741
PSEI

13,085

45,791

40,812
PWRX

2,992

90,351

9,389
SCL

4,846

26,468

9,964
SRP

78,761

213,086

58,569
TEPC

35,975

129,669

567
TIDC

13,745

9,460

300
TPWR

5,806

12,383

9,072

TABLE 6: Estimated wheel-through transfers in June 2022

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GRAPH 6: Estimated wheel-through transfers in June 2022
REDUCED RENEWABLE CURTAILMENT AND GHG REDUCTIONS
The WEIM benefit calculation includes the economic benefits that can be attributed to avoided
renewable curtailment within the ISO footprint. If not for energy transfers facilitated by the
WEIM, some renewable generation located within the ISO would have been curtailed via either
economic or exceptional dispatch. The total avoided renewable curtailment volume in MWh for
Q2 2022 was calculated to be 31,330 MWh (April) + 41,764 MWh (May) + 45,259 MWh (June) =
118,352 MWh total.
There are environmental benefits of avoided renewable curtailment as well. Under the
assumption that avoided renewable curtailments displace production from other resources at a
default emission rate of 0.428 metric tons CO2/MWh, avoided curtailments displaced an
estimated 50,655 metric tons of CO2 for Q2 2022. Avoided renewable curtailments also may
have contributed to an increased volume of renewable credits that would otherwise have been
unavailable. This report does not quantify the additional value in dollars associated with this
benefit. Total estimated reductions in the curtailment of renewable energy in the ISO footprint,
along with the associated reductions in CO2, are shown in Table 7.
Year Quarter MWh Eq. Tons CO2
1 8,860 3,792
2015 2 3,629 1,553
3 828 354
4 17,765 7,521
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1 112,948 48,342
2016 2 158,806 67,969 3 33,094 14,164
4 23,390 10,011
1 52,651 22,535
2017 2 67,055 28,700
3 23,331 9,986
4 18,060 7,730
1 65,860 28,188
2018 2 129,128 55,267
3 19,032 8,146
4 23,425 10,026
1 52,254 22,365
2019 2 132,937 56,897
3 33,843 14,485
4 35,254 15,089
1 86,740 37,125
2020 2 147,514 63,136
3 37,548 16,071
4 39,956 17,101
2021 1 76,147 32,591
2 109,059 46,677
3 23,042 9,862
4 38,044 16,283
2022 1 94,168 40,304
2 118,352 50,655
Total 1,782,720 762,925

TABLE 7: Total reduction in curtailment of renewable energy and associated reductions in CO2
FLEXIBLE RAMPING PROCUREMENT DIVERSITY SAVINGS
The WEIM facilitates procurement of flexible ramping capacity in the FMM to address variability
that may occur in the RTD. Because variability across different BAAs may happen in opposite
WEIM BENEFITS REPORT SECOND QUARTER 2022

MPP/MA&F Copyright 2022 California ISO Page 30 of 36
directions, the flexible ramping requirement for the entire WEIM footprint can be less than the
sum of individual BAA’s requirements. This difference is known as flexible ramping procurement
diversity savings.
Starting in 2016, the ISO replaced the flexible ramping constraint with flexible ramping products
that provide both upward and downward ramping. The minimum and maximum flexible ramping
requirements for each BAA and for each direction are listed in Table 8.
Month BAA Direction Minimum
requirement
Maximum
requirement
AVA up 21 91
April AZPS up 30 286
BANC up 7 113
CISO up 367 2,072
IPCO up 34 159
LADWP up 59 315
NEVP up 26 332
NWMT up 36 118
PACE up 116 516
PACW up 45 190
PGE up 33 177
PNM up 40 177
PSEI up 39 203
PWRX up 77 319
SCL up 5 45
SRP up 32 152
April TIDC up 2 14
TPWR up 3 29
ALL EIM up 471 2,759
AVA down 22 87
AZPS down 38 229
BANC down 5 88
CISO down 148 1,682
IPCO down 36 223
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LADWP down 45 279
NEVP down 16 395
NWMT down 31 135
PACE down 116 470
PACW down 60 186
PGE down 62 219
PNM down 49 163
PSEI down 27 174
PWRX down 76 314
SCL down 3 38
SRP down 17 160
TIDC down 1 19
TPWR down 4 34
ALL EIM down 326 2,122
AVA up 21 84
May AZPS up 33 286
BANC up 7 113
BPAT up 85 236
CISO up 363 2,072
IPCO up 38 159
LADWP up 66 315
NEVP up 0 332
NWMT up 36 129
May PACE up 118 516
PACW up 49 190
PGE up 51 277
PNM up 40 149
PSEI up 41 203
PWRX up 71 319
SCL up 5 45
SRP up 25 169
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TEPC up 37 135
TIDC up 0 14
TPWR up 4 25
ALL WEIM up 359 2,759
AVA down 33 84
AZPS down 38 229
BANC down 3 88
BPAT down 139 385
CISO down 142 1,682

May
IPCO down 61 223
LADWP down 51 279
NEVP down 0 395
NWMT down 38 135
PACE down 116 470
PACW down 55 221
PGE down 55 219
PNM down 40 163
PSEI down 36 174
PWRX down 59 314
SCL down 2 37
SRP down 15 143
TEPC down 33 149
TIDC down 1 19
TPWR down 3 19
ALL EIM down 337 2,122

June

AVA up 17 84
AZPS up 40 286
BANC up 7 113
BPAT up 64 407
CISO up 363 1,967
IPCO up 41 159
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June

June
LADWP up 66 315
NEVP up 0 332
NWMT up 24 128
PACE up 135 516
PACW up 47 200
PGE up 48 177
PNM up 34 179
PSEI up 40 203
PWRX up 71 225
SCL up 5 45
SRP up 30 169
TEPC up 42 135
TIDC up 0 15
TPWR up 4 26
ALL WEIM up 358 2,560
AVA down 23 84
AZPS down 39 229
BANC down 3 88
BPAT down 139 402
CISO down 149 1,682
IPCO down 63 223
LADWP down 56 279
NEVP down 0 327
NWMT down 30 156
PACE down 129 470
PACW down 57 221
PGE down 65 219
PNM down 45 163
PSEI down 33 174
PWRX down 67 239
SCL down 2 34
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SRP down 22 159
TEPC down 26 134
TIDC down 1 19
TPWR down 2 24
ALL WEIM down 342 2,122
Table 8: Flexible ramping requirements
The flexible ramping procurement diversity savings for all the intervals averaged over the month
are shown in Table 9. The percentage savings is the average MW savings divided by the sum of
the individual BAA requirements.
April May June
Direction Up Down Up Down Up Down
Average MW saving 1,387

1,397 1,676 1,428 1,747 1,504
Sum of BAA requirements 2,708 2,472 3,010 2,945 3,056 2,880
Percentage savings 51% 57% 56% 48% 57% 52%
Table 9: Flexible ramping procurement diversity savings in Q2 2022
Flexible ramping capacity may be used in RTD to handle uncertainties in the future interval. The
RTD flexible ramping capacity is prorated to each BAA. Flexible ramping surplus MW is defined
as the awarded flexible ramping capacity in RTD minus its share, and the flexible ramping
surplus cost is defined as the flexible ramping surplus MW multiplied by the flexible ramping
WEIM-wide marginal price. A positive flexible ramping surplus MW is the capacity that a BAA
provided to help other BAAs, and a negative flexible ramping surplus MW is the capacity that a
BAA received from other BAAs.
The EIM dispatch cost for a BAA with positive flexible ramping surplus MW is increased
because some capacities are used to help other BAAs. The flexible ramping surplus cost is
subtracted from the BAA’s WEIM dispatch cost to reflect the true dispatch cost of a BAA. Please
see the Benefit Report Methodology for more details.

CONCLUSION
Using state-of-the-art technology to find and deliver low-cost energy to meet real-time demand,
the WEIM demonstrates that utilities can realize financial and operational benefits through
increased coordination and optimization. In addition to these benefits, the WEIM provides
significant environmental benefits through the reduction of renewable curtailments during
periods of oversupply.
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Sharing resources across a larger geographic area reduces greenhouse gas emissions by using
renewable generation that otherwise would have been turned off. The quantified environmental
benefits from avoided curtailments of renewable generation from 2015 to-date reached 762,925
metric tons of CO2, roughly the equivalent of avoiding the emissions from 160,402 passenger
cars driven for one year.

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APPENDIX 1: GLOSSARY OF ABBREVIATIONS

Abbreviation Description
APS Arizona Public Service
AVA Avista Utilities
BAA Balancing Authority Area
BANC Balancing Authority of Northern California
BPA Bonneville Power Administration
CISO, ISO California ISO
EIM Energy Imbalance Market
FMM Fifteen Minute Market
GHG Greenhouse Gas
IPCO Idaho Power
LADWP Los Angeles Department of Water and Power
MW Megawatt
MWh Megawatt-Hour
NVE NV Energy
PAC PacifiCorp
PACE PacifiCorp East
PACW PacifiCorp West
PGE Portland General Electric
PSE Puget Sound Energy
PWRX Powerex
RTD Real Time Dispatch
SCL Seattle City Light
SRP Salt River Project
TEP Tucson Electric Power
TID Turlock Irrigation District
TPWR Tacoma Power
WEIM Western Energy Imbalance Market