It has a terrible ROI. If it didn't it wouldn't need constant and massive government subsidies, nor would it have to be forced on the public.
There is part of the problem. While you blithely go about things in your ignorance, the duplication of generation sources raises the cost of the system as a whole. The "electrical company" cannot just "turn off expensive electrical production." It takes time--hours to days--to bring a conventional generation station online or take it offline. It can't be done at the flick of a switch.