Reuters: Southern California Edison Co. said Thursday it plans to build the nation’s largest solar energy installation – an array of collector cells covering two square miles of rooftops that could power about 162,000 homes. The project, which was submitted to state regulators for approval, is an effort to meet the state’s mandate that 20 percent of California’s electricity be generated from renewable sources by 2010. Gov. Arnold Schwarzenegger attended the announcement, praising the …