I purchased PV because the cost with a 20-year loan comes out to be 13c kWh, meanwhile PG&E charges 29c kWh. And the loan interest is tax-deductible.
A lot of the solar companies were selling their low interest $0 down lease programs and they themselves were benefiting from the credits/rebates not the homeowner. Homeowners didn't really have to have a great credit score either. Once the credits and rebates went away, the lease programs weren't sustainable for the solar companies.
Just a few miles away in Santa Clara it would make no sense at all, since they have their own utility where power costs just 10c kWh.
There is something nice knowing your electricity costs are relatively fixed for 20 years though, since the price tends to follow the rate of inflation and the loan is fixed.