Cost savings for participants in both markets continue to grow

FOLSOM, Calif. – The latest California ISO’s Markets Quarterly Benefits Report was released today, showing increased cost savings for participants in both the real-time and day-ahead electricity markets.

In the 12-year-old Western Energy Imbalance Market (WEIM), cost savings for participants and their customers are nearly $10 billion. With the strong third quarter showing of $520 million in savings, the cumulative total savings since the market’s launch in 2014 is now $9.6 billion.

The report also showed growing cost savings for the Extended Day-Ahead Market (EDAM), which launched May 1 and recorded $11.38 for its first two months of operation. For the third quarter of the year, EDAM recorded $21.40 million in savings.  Total reported benefits since May are $32.77 million. 

“EDAM is already showing how greater regional coordination can help keep energy costs affordable while supporting reliable service. As more participants join and EDAM’s footprint expands, we expect those benefits to grow,” said Mike Wilding, vice president of energy supply management at PacifiCorp.

EDAM and WEIM use state-of-the-art technology to find and deliver low-cost energy to meet real-time demand, demonstrating that utilities can realize financial and operational benefits through increased coordination and optimization. 

The markets provide significant reliability benefits by enhancing situational awareness and supporting access to surplus energy across a broader western footprint.  In addition, the two markets provide significant environmental benefits through the reduction of renewable curtailments during periods of oversupply. 

Sharing resources across a larger geographic area reduces greenhouse gas emissions by accessing renewable generation that otherwise would have been turned off. The quantified environmental benefits from avoided curtailments of renewable generation since 2015 reached 1,296,262 metric tons of CO₂, roughly the equivalent of avoiding the emissions from 272,533 passenger cars driven for one year.

Also, by leveraging the significant resource diversity and transmission connectivity between major supply and demand regions throughout the West, EDAM is designed to deliver additional benefits to those realized in the WEIM through greater reliability coordination and resource optimization in the day-ahead timeframe, where the majority of energy transactions occur.

This latest report shows the following benefits, by participant, for the third quarter of this year, although Portland General Electric is not yet included because it only began participating in the market in the fourth quarter of 2026.

Q3 2026 Gross EDAM Benefits by Participant (entry year) - $ millions

For the WEIM, the third quarter report includes its two newest entities, both of which joined on May 1, with Black Hills showing $7.3 million in cost savings and Power Watch $2.2 million.