WASHINGTON – The Heartland Institute, a libertarian think tank skeptical of climate change science, has joined with the conservative American Legislative Exchange Council to write model legislation aimed at reversing state renewable energy mandates across the country.

The Electricity Freedom Act, adopted by the council’s board of directors in October, would repeal state standards requiring utilities to get a portion of their electricity from renewable power, calling it “essentially a tax on consumers of electricity.”

Twenty-nine states and the District of Columbia have binding renewable standards; in the absence of federal climate legislation, these initiatives have become the subject of intense political battles.

Maine is among the states that have adopted renewable power standards. In 1999, the state passed a law that required 30 percent of retail electric sales to come from renewables. That law was updated in 2006 with a goal of increasing the standard by an additional 10 percentage points between 2008 and 2017.

Maine’s standard has plenty of critics, most notably Gov. Paul LePage, who often has said the law hampers the state’s ability to diversify its energy offerings and reduce costs for consumers.

ALEC, the council that is looking to write new model standards, is a conservative-leaning group of state legislators from all 50 states that has sought to roll back climate regulation in the past. It lost some corporate sponsors early this year because of its role promoting “stand your ground” laws that allow the use of force in self-defense without first retreating when faced with a serious threat.

But the involvement of the Heartland Institute, which posted a billboard in May comparing those who believe in global warming to domestic terrorist Theodore Kaczynski, shows the breadth of conservatives’ efforts to undermine environmental initiatives on the state and federal level. In many cases, the groups involved accept money from oil, gas and coal companies that compete against renewable energy suppliers.

The Heartland Institute received $736,500 from Exxon Mobil between 1998 and 2006, according to the group’s spokesman Jim Lakely, and $25,000 in 2011 from foundations affiliated with Charles G. Koch and David H. Koch, whose firm Koch Industries has substantial oil and energy holdings. Lakely wrote in an e-mail that the Koch donation was “earmarked for our work on health care policy, not energy or environment policy.” He added the institute had received financial support from the Koch brothers before 2001, but did not specify how much.

James Taylor, the Heartland Institute’s senior fellow for environmental policy, said he was able to persuade most of ALEC’s state legislators and corporate members to push for a repeal of laws requiring more solar and wind power use on the basis of economics.

“Renewable power mandates are very costly to consumers throughout the 50 states, and we feel it is important that consumers have access to affordable electricity,” Taylor said. “We wrote the model legislation and I presented it. I didn’t have to give that much of a case for it.”

Taylor dismissed the idea that his group pushed for the measure because it has accepted money from fossil-fuel firms: “The people who are saying that are trying to take attention away from the real issue — that alternative energy, renewable energy, is more expensive than conventional energy.”

Todd Wynn, who directs ALEC’s energy, environment and agriculture task force, said the group decided to take up the issue because some members are worried about the mandates’ “impacts on their state’s economies and their constituents.”

“It is not that ALEC is opposed to renewable energy in any way,” Wynn said. “But we are opposed to government intervention mandating certain energy sources over others.”

But renewable energy officials — including ones from the Solar Energy Industries Association and the American Wind Energy Association, both ALEC members — questioned the new policy. Setting renewable targets is a popular way to diversify a state’s energy mix and lock in long-term prices, they said, while alternative energy costs continue to decline.

“ALEC is going to wake up and realize that the Heartland Institute, which is funded by special interests, is pushing them in a direction that’s making them irrelevant to, or at best out of touch with, the American public,” said SEIA President Rhone Resch. “And they can’t afford to do that.”

As part of its effort to roll back renewable standards, ALEC is citing economic analyses of state policies co-published by Suffolk University’s Beacon Hill Institute and the State Policy Network. Both groups have received donations from foundations funded by the Koch brothers, who support libertarian causes.

The analyses — which examine current or proposed standards in such states as Kansas, Maine, Michigan, Missouri, North Carolina and Oregon — assume that the Energy Information Administration’s projected renewable energy price estimates are too low, and that cost-containment measures embedded in state policies will fail. As a result, the reports conclude Kansas’ requirement to obtain 20 percent of its electricity will cost consumers $644 million over the next eight years.

LePage and the conservative advocacy group Maine Heritage Policy Center have cited the Beacon Hill Institute study as evidence that Maine’s renewable energy standards will increase energy costs by $145 million by 2017.

It’s unclear whether this drive to repeal state renewable standards will succeed: Similar efforts in the past two years have failed in California, Colorado, Connecticut, Kansas, Massachusetts, Ohio, Oregon and Washington.

“Renewable standards passed over the last decade have been supported on a bipartisan basis, and that was before the dramatic growth in manufacturing and construction jobs the industry created,” said Rob Gramlich, the American Wind Energy Association’s senior vice president for public policy. “Attacks on state renewable energy policies in 2012 failed consistently and we are confident they will again in 2013.”

Wynn said that while it may be hard to make headway next year, he was optimistic his side could start to dismantle some state requirements in 2014.

“These discussions are just starting to ramp up, and the impacts of these mandates are just starting to be seen in these states,” he said.

It’s possible that a Maine lawmaker might submit a bill similar to ALEC’s model legislation. However, now that the House and Senate are back under Democratic control, it’s unlikely that such a law could get enough votes to pass.

It might be more likely that Maine’s law changes in a different way. Late last year, a coalition called Maine Citizens for Clean Energy began gathering signatures to force a citizens’ initiative that would ask Mainers to support or reject an additional expansion of the renewable energy standards law. The group failed to gather enough signatures and, in January, said it would likely try for a ballot initiative in 2013.

LePage was critical of that effort, calling it a “job killer.”

Press Herald Staff Writer Eric Russell contributed to this story.

This story was updated at 11:33 p.m. Nov. 25 to correct the amount of money the Heartland Institute received from Exxon Mobil and foundations affiliated with Charles G. Koch and David H. Koch.