The U.S. Navy is aiming for a 50 percent alternative energy goal for its bases by 2020, Ray Mabus, secretary of the Navy, told the Senate Energy & Natural Resources Subcommittee on Water & Power March 12. As part of its effort, Mabus noted the Navy is pursuing power purchase agreements under which private developers build large-scale renewable energy projects on bases that can minimize their reliance on the grid. In California, the Navy’s China Lake base is home to a 270 MW geothermal plant, said Mabus. The Navy, he added, hopes to further develop geothermal power there. In addition, the secretary explained that the Navy has entered three power purchase agreements with solar project developers at its China Lake, 29 Palms, and Barstow bases in California. At its Miramar base in San Diego, the Navy has partnered with a sanitation agency to tap landfill gas for power. When the project is finished, he said, it would meet 50 percent of the base’s power needs.