[quote=walterwhite]theya dd to your cost but they also add to the electricity produced, pushing forward your payback date. since there’s installation costs that remain stable, more is better, but not that much better. the panels are most of the cost[/quote]

But at what rate will sdge buy the excess generated electricity? You are looking at having only a single purchaser that will set his price for your “product”. The risk your initial investment would be too costly will still be quite high.