The Western Energy Imbalance Market (WEIM), a real-time energy market operated by the California Independent System Operator (CAISO), has gained three new participants, including its first generation-only entity.
CAISO on April 5 announced the Western Area Power Administration (WAPA) Desert Southwest region, El Paso Electric (EPE), and AVANGRID have formally begun participation in the WEIM. WEIM’s 22 active participants, which now span 11 Western states, represent “nearly 80% of the demand for electricity in the Western interconnection,” CAISO said.
The WEIM, an energy-only market established in 2014 by CAISO and PacifiCorp, allows participants that are not transmission owners in the CAISO grid to sell energy in real-time—on a 15-minute and 5-minute basis—to balance their supply and demand.
The market’s platform is designed to resolve grid stress within the Western Interconnection by enabling energy transfers, essentially giving participants—which span across multiple Western states—access to a larger pool of diverse resources. Participants, however, determine how transmission and generation resources engage in the market, allowing them to control their assets and maintain their own compliance responsibilities.
“The WEIM is designed to enable participants to buy and sell power close to the time electricity is consumed. With state-of-the-art technology, the market finds and delivers lowest-cost resources to meet immediate power needs and manages congestion on transmission lines to maintain grid reliability,” CAISO explains.
“The WEIM is designed to enable participants to buy and sell power close to the time electricity is consumed. With state-of-the-art technology, the market finds and delivers lowest-cost resources to meet immediate power needs and manages congestion on transmission lines to maintain grid reliability,” CAISO explains.