No one is keeping anyone from putting solar panels on their house. However, once you realize that the things only put out 2 or 4 amps per panel under perfect conditions (pointed directly at sun, no cloud cover, no dust, dirt, or leaves on your roof), you realize the futility of this dream at least under current technology.
FWIW (and this will sound odd against my golf cart rant). I've really been looking into some sort of electric commuter vehicle for when I don't feel like riding my bike to work (like today).
I really like the Zero Motor cycles. From an EV standpoint they are kind of a golf cart to charge. Now, when looking at this light moto to stick on the back of my truck I though.. Oh wait.. I'll just charge it from the 160-200watt solar array on the roof. No dice, just not enough power to do that even sitting in the middle of death valley on a clear day.
Now.. with about 4 8D batteries and a decent inverter with a fairly large array on a house, you should be able to save enough juice during the day to charge a moto or golf cart, but we're still not there yet for charging something like a telsa or a Leaf (man that's a painfully ugly vehicle)..
CARB currently really has a thing against particulate matter. Diesels still make some = diesels seem evil no matter what they do. I'd fully expect tighter regs than current in the future (They did just start doing the smoke tests on diesels in the last year @ smog stations). Some would say.. well that's just CA, it won't affect other states.. but 1.) They influence the EPA pretty bad, and 2.) There are several states that nearly use the CARB rules verbatim.
I do see how the air sits in these valleys on warm days though. It just doesn't move like it does in a lot of places. I have a bit more appreciation for CARB than I did before moving out here.. But still they need a little work.