Demand for solar energy has increased in recent years as the cost of installing the systems has fallen and homeowners and businesses have tried to save money on energy bills. That in turn has prompted utilities to push back against solar's rapid encroachment on the retail market—and they're doing so in Washington and in state legislatures.
At issue is something called "net metering." It's the process by which solar owners can measure the extra power they generate from their panels, and then send it back to the grid at retail rates. That's the way such customers save on their monthly electricity bills.
Utility companies' efforts come at a time when investors are again showing signs of enthusiasm for solar stocks. Shares of First Solar and SunPower were leaping on Tuesday on news that the two plan a joint IPO. Other big solar names, such as Elon Musk'sSolarCity, were also rising Tuesday.
Read More Solar firms, power companies battle over 'net metering'
"We've seen utilities across the country try to eliminate solar competition," said Bryan Miller, vice president of public policy for Sunrun, a California-based solar energy company. "They're trying to manipulate the political process, but it's not working."
Still, disgruntled utility companies are taking the fight to Washington. And anti-net metering proposals have cropped up in several states including Arizona, California and Utah.
The utility industry points out that it invests in solar projects itself and presents consumers with its own solar power options, including financing. But it also believes that grid infrastructure costs should be shared among all consumers.
"We believe that public policies must recognize the value of the grid to all customers, and regulatory structures must be applied that sustainably and fairly support both the growth of rooftop solar systems and the grid infrastructure that enable the integration of these technologies," said David Owens, an executive with the Edison Electric Institute, a utillities trade association.
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Miller, who is also with the Alliance for Solar Choice, a solar power advocacy group. is betting on public opinion going the way of the solar industry. In addition to increasing demand for solar power, polls show support for renewable energy to be high. In 2012, the Solar Energy Industries Association found that 92 percent of voters believe it is important for the country to develop and use more solar energy.
Groups from across the political spectrum have shown up in support of solar, including the Christian Coalition and the conservative T.U.S.K. (Tell Utilities Solar won't be Killed), which supports solar power on a free markets basis and is chaired by former congressman Barry Goldwater Jr.
"More competition is good for everyone, except the utility monopolies," Miller said. "Eventually they will lose the fight in Washington, become deregulated and broken up, because the markets have to open."