CAISO: Two more utilities join the Western Energy Imbalance Market

Summary:

Avista Utilities and Tacoma Power, two utilities serving a combined 600,000 electric customers in the Pacific Northwest, are the newest members of the Western Energy Imbalance Market (WEIM), with both beginning their participation. Avista Utilities, which serves more than 400,000 electric customers in Washington and Idaho, and Tacoma Power, a publicly owned utility serving nearly 200,000 electric customers in the Tacoma, Washington, area since 1893, are the first of four utilities joining the real-time energy market in 2022. Bonneville Power Administration and Tucson Electric Power will become active WEIM participants later this year. Once all four utilities have joined, the WEIM will have 19 members serving nearly 77 percent of the demand for electricity in the Western United States. While more utilities join the WEIM, the ISO is working to build on its success through the development of an Extended Day-Ahead Market, where the majority of energy transactions occur for participants. The stakeholder initiative process, which began in January, has established three working groups each focused on a market component that is instrumental in building a proposal that will meet the needs of the ISO’s partners in the West.

Additional Discussion:

The WEIM uses sophisticated technology to find and deliver the lowest-cost energy to its members, while enhancing reliability and providing significant environmental benefits through the reduction of renewable energy curtailments during periods of oversupply. Reducing curtailments leads to lower greenhouse gas emissions because the renewable energy - rather than going unused - can be deployed by other market participants, and may displace power generated using fossil fuels.