Critics of tax credits for wind energy projects are intensifying their push to kill the incentive with a study that calls it “rent seeking” by an established industry that doesn’t need the subsidy.

The conservative American Energy Alliance (AEA) unveiled the study Thursday as wind power companies — joined by allies including President Obama — are pushing Congress to renew credits that are scheduled to lapse at year’s end.

AEA, which receives some of its funding from fossil fuel companies, is circulating the study on Capitol Hill ahead of a lame-duck battle over the fate of the multibillion-dollar incentive.

The group is also promoting the study to editorial boards, governors and others.

AEA commissioned a study by Louisiana State University economist David Dismukes that argues the 20-year-old production tax credit (PTC) provides “training wheels” to an industry that doesn’t need them — especially at taxpayers’ expense.