The “most likely” outcome for the wind production tax credit (PTC) is another “simple one-year extension” in late 2015, says Robo, describing it as "kicking the can down the road".

Florida-based NextEra Energy is the largest owner of both wind and solar capacity in the US.

“I do think there’s a chance you’d see a multi-year phase out” of the PTC, Robo says.