The San Diego County Water Authority and the City of San Diego are testing the waters on a pumped storage project that could help provide the region with up to 500 MW of clean energy, Windpower Engineering reports. The agency last week released a joint request for letters from electric utilities, developers, investors and energy consumers, to try and gauge interest in the project. Central to the proposal is an interconnection and pumping system between the existing San Vicente Reservoir and a new, smaller reservoir located uphill