Since 2007, California has experienced a solar boom. Photovoltaic panels rest on 107,159 rooftops, as of this writing (the numbers are updated here every Wednesday). Driven by incentives that are bankrolled by every Californian who pays a utility bill, Californians now have more than one Gigawatt of solar capacity installed over our heads That’s a lot: one Gigawatt is roughly the size of one of the state’s four nuclear power plants, although solar PV panels do not produce power at the steady, even rate that nukes do.