The San Diego County Water Authority announced it will seek detailed proposals for a potential energy storage facility at the San Vicente Reservoir that could total up to 500 MW. The official RFP will go out this summer.The request for proposals follows a January request for letters of intent to measure interest in the facility. In response, the Water Authority received 18 responses from qualified parties, including five full-service entities that would finance, design, permit, built and operate the potential project and secure an off-taker for the produced energy.