Americans have begun to battle over sunshine. In sun-scorched Arizona a regulatory skirmish has broken out over arrays of blue-black silicon panels on rooftops, threatening the local utilities that have ruled electricity generation for a century or more. With some of the best access to sunshine on the planet, Arizona boasts the second-most solar power in the U.S.—more than 1,000 megawatts and counting. The state hosts vast photovoltaic arrays in the desert as well as the nation’s first commercial power plant with the technology to use sunshine at night—by storing daytime heat in molten salts.
In terms of infrastructure, such big solar fits as comfortably as a coal-fired power plant in the traditional electricity business model, which involves large plants transmitting electricity over a grid of conducting lines through transformers and into individual homes and businesses. The trouble, from an electric utility’s perspective, is the tens of thousands of Arizona’s total of three million or so homes that have installed small solar: photovoltaic panels made from wafers of semiconducting material, typically silicon, that use incoming sunlight to create an electric current. With these homes making their own electricity, utilities lose their most lucrative customers and confront a dwindling base over which to spread big infrastructure costs, like building new power plants or maintaining the grid. “The net-metered customer does not share equally in the overhead costs associated with the grid or other services provided by the utility, producing a very substantial ‘cross-subsidy’ funded by all other utility customers who must pay proportionately more,” wrote James Hughes, CEO of solar panel maker First Solar, in an op-ed in support of the utility Arizona Public Service Co. (APS) position this past June. . . .