It's mostly shortage of labor: if you're willing to do the research on your setup, buy the equipment yourself, and just hand instructions+gear to a contractor,

It's mostly shortage of labor: if you're willing to do the research on your setup, buy the equipment yourself, and just hand instructions+gear to a contractor, you save a bunch of money. If you're willing/able to do the installation yourself, you save even more. This isn't specifically a rooftop solar thing, the entire construction industry in America has been bottlenecked on labor for years. You can insert your own personal hobbyhorse here about why that is (immigration, undervaluing trades, etc.), but whatever it is it sure is a headwind on solar migration.