That seemed like a really big system, but thats what I came up with using the calculators I had found online (basically, monthly kWh divided by monthly sun hours with a fudge factor- basically 3.5*30 for sun hours multiplied by 0.77 to account for inefficiencies in the system from the inverter, etc).

In CA the big tax incentives (California Solar Initiative) ran out of money. I looked, and I think the only local incentive I can get is a $500 credit from my utility.