Using co-optimization to clear energy and ancillary services in MRTU market

Summary form only given. The CAISO is completing the implementation of it market redesign and technology upgrade (MRTU). Currently, the ancillary services at the CAISO is approximately a $300 million annual market. In conjunction with the market redesign, the CAISO is implementing a co-optimization of energy subject to transmission constraints and ancillary services subject to resource constraints. Prior to MRTU, the CAISO procured ancillary services in the day-ahead market sequentially after allocating transmission using a ration buyer approach. In this presentation we will provide a status update of implementation of the energy and ancillary service co-optimization. We intend to present high level information how the ancillary service constraint is formulated. In addition, we will provide a summary of experience with the new ancillary service procurement methodology during market simulation. Lastly, we will provide insight into areas in which ancillary service procurement can be further enhanced in the future better ensure deliverability of such reserves from both a transmission constraint and resource ramping constraint perspective.