A new regulation that took effect on the island of Oahu in September, requiring installers of rooftop solar panels to get permission from the utility before hooking up to the power grid, is having a chilling effect on the solar power industry there, according to a Reuters report published on Yahoo News (see: "Analysis: Clouds over Hawaii's rooftop solar growth hint at U.S. battle," by Nichola Groom).

"What's happening in Hawaii is a sign of battles to come in the rest of the United States, solar industry and electric utility executives said," Reuters reported. "The conflict is the latest variation on what was a controversial issue this year in top solar markets California and Arizona. It was a hot topic at a solar industry conference last week: how to foster the growth of rooftop solar power while easing the concerns of regulated utilities that see its rise as a threat."

Oahu, of course, is an island — which means that the waxing and waning of solar panel output between noon and midnight, along with the momentary variations caused by passing clouds, can't be spread across an extensive regional power grid. Reports Reuters: "Hawaiian Electric, an investor-owned utility, has serious concerns. The inconsistent power generated by so many rooftop solar systems threatens the safety and reliability of its small, independent power grids, a Hawaiian Electric executive said. The utility, which must balance generation supplies with demand, has no control over the power flowing from the roughly 200 megawatts of rooftop systems on Oahu. Unlike large power projects that the utility owns and operates, there is no mechanism in place for the company to see how much electricity the rooftop PV systems are sending to the grid at any given moment."

But the same battle is brewing over mainland solar power, Reuters reports: "The recent tensions between Hawaiian Electric and the solar industry resembled high-stakes battles this year over a major solar incentive in California, Arizona and elsewhere. In those states, utilities argued that increasing numbers of homeowners going solar - and getting paid by the utility for the excess power their systems generate, under a policy known as net energy metering - will force ratepayers without solar systems to shoulder the cost of maintaining the power grid."