These requirements, known as renewable portfolio standards (RPSs), are being targeted by the American Legislative Exchange Council (ALEC).
The group, which drafts "free market", libertarian and conservative model legislation for state lawmakers in many different areas of policy, has private-sector advisers that include representatives from coal giant Peabody Energy, oil and gas multinational Exxon Mobil and a division of fossil-fuel conglomerate Koch Industries.
ALEC's Electricity Freedom Act, if adopted by a local state legislatures, would repeal RPSs, according to an ALEC newsletter published just days before the general election. RPSs are one of two key drivers of wind development in the US in recent years, along with favourable tax policies such as the wind production tax credit (PTC). In January 2012, 30 states and the District of Columbia had an enforceable RPS or other mandated renewable capacity policy.
So far this year, efforts to repeal RPSs have largely failed, according to the Database on State Incentives for Renewables & Efficiency (DSIRE), funded by the US Department of Energy. There were "many attempts to kill, maim or disembowel RPS policies this year", said DSIRE in a survey, but only a few such bills were passed.
The attempts included five bills that would have frozen or repealed an existing RPS - in Michigan and West Virginia - and 14 bills that that would have weakened RPSs in states from California to Maine. Ohio's RPS was successfully watered down so that it can partly be met by any repowered, retrofitted or refueled power plants. New Hampshire's was also diluted.
A proposition to amend Michigan's state constitution so that 25% of electricity must come from renewables by 2025 was soundly beaten, along with four other proposals to amend the constitution. It was the most-watched state vote on renewable energy.
Rob Gramlich, senior vice president for public policy at the American Wind Energy Association, said that the Michigan proposition fell victim to a broad rejection of all constitutional amendments by voters in the state. "Public support for renewable energy in the state remained strong, but the number of proposals led to a crowded ballot and voter concerns about changing the constitution," Gramlich said.
A post-election survey by lobby group the American Council on Renewable Energy found that more than 60% of voters in each state of Ohio, Iowa and Colorado - all of which have strong wind sectors - and also in Virginia, wanted an RPS to foster renewable energy in their state. Wind came second only to natural gas in a survey of support for gas and renewables.
The researchers, from Public Opinion Strategies and Fairbank, Maslin, Maullin, Metz & Associates, also found that a majority of voters said energy issues influenced their vote and that they preferred a pro-clean energy stand by any candidate, regardless of party.
The voters also said that they preferred the energy strategy of President Obama, who backed wind jobs and the PTC energy avidly, compared with the fossil-fuel oriented strategy of his unsuccessful opponent, Mitt Romney.
In another strong statement for wind, the Red State Renewable Alliance has been launched by well-known Republican strategist John Feehery to boost wind energy in conservative constituencies.
"We at the Red State Renewable Alliance will tell the story of wind energy and the wind PTC in new and innovative ways,"
said Feehery. "We we will convert the doubters out there."
Republican congressional districts are home to 75% of the US's installed wind capacity and 67% of the industry's wind manufacturing base.