Western EIM’s new participants successfully begin testing stage
Arizona Public Service and Puget Sound Energy fully enter market Oct. 1In preparation for full entry into the western Energy Imbalance Market (EIM) this October, the California Independent System Operator (ISO) today initiated the operations testing stage with Arizona Public Service (APS) and Puget Sound Energy (PSE). Over the next several weeks, the EIM’s newest participants and the ISO will operate under real conditions but transactions will not be financially binding until October 1. The parallel operations will give system engineers, grid operators and market managers a test period