As I lived in the Bay Area during the energy debacle in 2000, I have watched this initiative with great interest. California leads the nation in subsidizing rooftop solar. Most of these systems are grid-tie systems which don't require storage batteries. They use grid-tie inverters to feed the grid such as made by Xantrex. Even so, this can be quite an investment with a long (10-15 year) payback. Looks like the subsidies along with new federal tax credits are driving adoption in California.
The closest thing we have in TN is Green Power Switch. Here as a residential you can buy green power from TVA or one of its distributors. Green generation is at the utility level with this plan.