Participants in CAISO’s Western Energy Imbalance Market saw a record $526 million in benefits in the third quarter of 2022 as the market approached $3 billion in total benefits, six months after it passed the $2 billion mark.
The results outstripped the next highest quarter, Q3 2021, by $225 million. The new record was the result of more participants in the interstate WEIM and “economical transfers displacing more expensive generation,” especially during September’s Western heat wave, CAISO said in its third-quarter report Oct. 31.
“Resource sharing among WEIM participants during this summer’s extraordinary 10-day heat wave provided meaningful economic benefits while helping maintain reliability for millions of consumers in the West,” Stacey Crowley, CAISO vice president of external affairs, said in a news release.
The Balancing Authority of Northern California (BANC) had more than $111 million in benefits in Q3. BANC consists of inland areas where temperatures set records in September. One BANC member, Sacramento Municipal Utility District, warned customers of potential outages as the high hit 116 degrees Fahrenheit in Sacramento on Sept. 6.
Other BANC members, such as Modesto Irrigation District and Turlock Irrigation District, also dealt with record-high temperatures and soaring demand.
PacifiCorp obtained $84.5 million in benefits last quarter, while CAISO saw $66 million in benefits. Other large beneficiaries included Southwest utilities NV Energy ($62 million), Arizona Public Service ($36 million) and Tucson Electric Power ($27 million).
The third quarter was the first full quarter of WEIM participation for Tucson Electric Power and the Bonneville Power Administration, which obtained a bit more than $9 million in benefits.
With 19 participants, the WEIM “finds and delivers the lowest-cost resources to meet immediate power needs and manages congestion on transmission lines to maintain grid reliability,” the news release said.
CAISO expects the WEIM to encompass 80% of load in the Western Interconnection by next year, after the entry of new participants El Paso Electric Co. and the Western Area Power Administration’s Desert Southwest Region.
Since WEIM began operations in November 2014, its cumulative economic benefits have totaled $2.91 billion, the ISO said.
“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,” CAISO said in its quarterly report.
WEIM surpassed $2 billion in cumulative benefits in Q1 2022, 20 months after it reached $1 billion in total benefits. The entry of new participants accelerated and compounded the market’s overall benefits, the ISO said at the time.
CAISO has cited the economic benefits of the real-time WEIM as reason for utilities to join its proposed expanded day-ahead market (EDAM), which it hopes to bring before its board of governors and the WEIM’s Governing Body in December.