A wind power tax credit expires at the end of December. To earn it, wind farm operators have to have their turbines up, running and plugged in. - 

The production tax credit for wind power means companies that build giant wind turbines get a 30 percent rebate. That is, if they're spinning and delivering energy to customers by year's end. So a lot of construction crews are working through the holidays, says Scott Clavenna, CEO of Greentech Media, rushing to get things installed and connected.

"There really is this hard and fast rule, that the wind farm has to be put into service by December 31," he says.

This year will look like a great year for wind power on paper because developers pushed to meet the deadline. But Clavenna says even if the tax credit is renewed at the eleventh hour, the uncertainly around it means bad news for production.

"Basically the market will crash next year," he says. "There's no exception to that possibility."

Wind turbine manufacturing stands to lose tens of thousands of jobs, many in the Midwest. In the long term, though, the wind power industry will grow, says Michael Skelly. He runs Clean Line, a company that connects wind farms to the power grid. His business for the coming years looks strong.

"We depend on demand in renewable energy," he says, "and we think the fundamentals around that are very strong."

He says there's more to wind power than just making more turbines. Transmission lines and other infrastructure can still be developed for existing wind farms.

Follow Eve Troeh at @evetroeh