The letter, sent Thursday, noted the U.S. Energy Information Administration (EIA) predicted state mandates would help renewable generation grow more than 50 percent by 2035.
By that year, EIA projected renewables to comprise 11 percent of the nation’s energy use, up from 7 percent in 2010.
The groups argued those state targets make giving the 2.2-cent-per-kilowatt-hour wind credit another year unnecessary.
“This guaranteed increase in market share is not offered to any other type of traditional power generation technology, such as natural gas, coal, or nuclear,” the letter said.
Letter signatories included the American Energy Alliance, Heritage Action, Freedom Action, Competitive Enterprise Institute and American Commitment.
Those groups sent a letter last week urging lawmakers representing states without renewable targets to axe the wind credit. They argued the incentive helped other states while failing to benefit those without mandates.
Fiscal conservatives want to end the credit, which expires Dec. 31, because they say the federal government cannot afford it with the current deficit situation.
Proponents of the credit are pushing for a one-year extension at a cost of $12.1 billion through 10 years. They say the credit is bringing the wind industry closer to self-sufficiency, arguing that letting it die would also kill 37,000 jobs.
The American Wind Energy Association recently suggested extending the incentive one year, and then phasing it out through the next five. The trade group said the industry would be cost-competitive with other energy sources by the end of that period.