San Francisco Chronicle: One of the keys to the expansion of solar power has been the opportunity for homeowners and businesses to receive credits for the amount of excess electricity they send back to the grid. This incentive – known as a “net metering” requirement – was broadened under the 2006 California Solar Initiative, which was designed to put the state in the forefront of alternative energy generation. That law required investor-owned utilities, such as the Pacific Gas & Electric Co., to provide such …