Rooftop solar installation businesses in the US are starting to recover from a slump triggered by higher interest rates and cuts in incentives for panels in California, according to Sunnova Energy International Inc. Chief Executive Officer John Berger.

“We are through the worst side of things, if you will,” Berger said Thursday during an interview on Bloomberg TV. “We see industry volumes picking back up either this quarter or probably in quarter one and moving up and going back into growth.”