But the idea is likely to encounter Republican opposition. Senate Finance Chairman Chuck Grassley, an Iowa Republican, said he doesn’t favor another extension for either of the credits. He said he committed to opponents of the wind tax credit in 2015 that he wouldn’t try again.

“I said ‘If you go along with this phaseout that is the end of it,”’ Grassley said in an interview, adding the wind energy industry agreed to those terms as well.

Not all Republicans are against an extension.

“I’d want to see what the package looked like, but we are pretty big on wind energy in Texas,” said Senator John Cornyn of Texas. “I would be certainly favorably inclined.”

Opponents of the credits say they aren’t surprised by the effort to renew them.

“That’s the thing with these tax credits -- they never go away,” said Tom Pyle, president of the American Energy Alliance, a free-market advocacy group. “They’re like zombies.”

In the Senate, Minority Leader Chuck Schumer, a New York Democrat, supports an extension of the wind and solar tax credit, and Maryland Democrat Ben Cardin, a member of the Senate’s tax-writing committee, has suggested using fixes sought by Republicans to the tax overhaul passed in 2017 as leverage to get them.

“That’s going to require some attention to our priorities,” Cardin said in an interview, where he also expressed support for extending a consumer tax credit for the purchase of electric vehicles. “There is a lot of trading that goes on around here.”

Republicans Needed
An extension of the credits would need the backing of Senate Republicans to pass and would represent a bonanza for the solar and wind industries. Rooftop solar installer Solar City Corp. surged 34% after the 2015 deal was announced. BloombergNEF predicted the credits’ extension would lead to $73 billion in new investment and a 56% increase in new wind and solar capacity.

Yet the prospect of another extension represents a predicament of sorts for the wind and solar industry, with some companies making the case in 2015 that a multiyear extension of their tax credits was the last support they would need to become cost-competitive with traditional energy sources.