The tussle over the future of solar energy in Maine also is a fight over competing visions for how to develop the limitless resource. One continues the existing model of centralized power moving through a regional electric grid. The other is power produced close to where it’s consumed, through community or home-based systems. That model is called distributed generation.

Solar has emerged as the focus for distributed generation because it has a human scale. Most wind turbines in Maine are utility-size projects located on remote ridgetops, where breezes are strongest. But anyone with a south-facing roof or an open field can tap free power from the sun. Access to sunshine nurtures the dream that, someday, whole neighborhoods will cut the utility umbilical cord and, aided by new battery technology, say farewell to the power company.

That’s not what Central Maine Power Co. has in mind.

Clean-energy advocates often see utilities as enemies of solar, but that’s not accurate. In some states, utilities are major solar developers. In Maine, utilities were forced to sell their generating assets when the electric industry was restructured 15 years ago. Now, they’re looking for a do-over.

CMP’S AMBITIONS UNDER FIRE

A bill introduced on behalf of Gov. Paul LePage that would let Maine utilities own generation if it’s deemed beneficial to ratepayers was carried over until next year. Meanwhile, CMP testified during legislative hearings on the solar bills that Maine is the only state in the Northeast where utilities can’t own or develop solar generation. It noted that utility-size solar systems produce electricity at half the cost of home installations.

“Solar is a valuable resource,” said John Carroll, a CMP spokesman. “People keep pointing out that Maine is falling behind in solar, but that’s largely because Maine utilities aren’t building grid-scale solar.”

Carroll said Maine should take advantage of the fact that CMP’s parent company has a clean-energy subsidiary, Ibedrola Renewables. It’s the second-largest wind company in the United States and operates solar projects in New Mexico and Arizona.

CMP’s aspirations have come under fire from a national coalition of rooftop solar installers that include industry leaders, such as Solar City and Sunrun. These companies don’t operate in Maine, but they’ve been trying to build support here through lobbying and online advertising.

The Alliance for Solar Choice says Maine is the latest state in which utility monopolies are waging a campaign to keep homeowners tied to the grid. It testified at a public hearing on a sweeping energy bill introduced on behalf of LePage which, among other things, would have repealed Maine’s net-metering rule. The bill didn’t make it through the Legislature.

Under the rule, utilities pay homeowners for the electricity they produce, even though they need to buy power from the grid at night and on cloudy days. CMP says net metering is an outdated concept that shifts the cost of maintaining its distribution network onto other customers, and will get worse as more solar is installed. The alliance says net metering is the foundation for solar policy in 44 states and benefits all ratepayers.

PUBLIC ADVOCATE’S PROPOSAL

But in Maine, there’s momentum to come up with an alternative to net metering.

Maine Public Advocate Tim Schneider has developed a framework in which solar generation is compensated through a bidding process that reflects the value of power in a long-term contract. The concept builds on a landmark study released early this year by the Public Utilities Commission that found solar energy has a benefit to all electric customers that exceeds the state’s retail rate of 13 cents per kilowatt-hour.

The study process is being supported by a stakeholder group that includes an influential solar advocate in the Legislature, Rep. Sara Gideon, D-Freeport, the Natural Resources Council of Maine and key Maine solar installers, including ReVision Energy.

Dylan Voorhees, the council’s clean-energy director, said he’s disappointed that bills that would have created financial incentives for solar foundered this year in the Legislature. But he said the net-metering alternative could put Maine on a path to a sustainable solar industry, especially if the 30 percent federal tax credit for solar installations expires at the end of 2016.

“The public advocate’s proposal has some real potential,” he said. “It could lead to a long-term policy that helps solar. But it will take another year or more of work, and the outcome is uncertain.”