Prompted by pressure from clean energy advocates, Hawaii and California are quietly working to remove a regulation that makes it difficult to install residential clean energy installations, once the total amount of such home generated power in a locality exceeds 15% at peak demand, reports Maria Gallucci at Inside Climate News. Beyond 15%, new proposals must go through lengthy and expensive studies to proceed. This regulation originated about a decade ago, because of worries that home generated solar installations would threaten the stability of the electric grid, causing blackouts, surges, and equipment damage. But both states are approaching that 15% threshold, and it is killing the further spread of solar installations, Isaac Moriwake, a Honolulu-based attorney with Earthjustice, a national environmental law firm, noted. He represented the Hawaii Solar Energy Association in settlement talks that led Hawaii to ease their restrictions. California is now following Hawaii’s lead in easing in new installations. Any changes made in Hawaii and California could have national implications, experts say, since most other states have adopted the 15 percent rule and the study requirement, and rooftop solar is spreading fast.