However I think you will find the ROI on this type of investment very low based on your location. I am in Ohio and the number of sun days makes this a very long term investment.
There are some really good state and federal incentives available that will significantly shorten the time to recoup the initial investment. In Virginia, the Dept. of Mines, Minerals and Energy took reservations for rebates on solar PV and wind systems. We were approved for up to a 20kW system with the rebate amount being equal to $2/kW for the first 10kW and $1.75/kW for the next 10kW.
I *think* we can get a 10kW system installed for about $50,000. We would then get $20,000 back from the state rebate and a 30% federal tax credit of $16,665. This brings the net out of pocket expense to $13,335. Depending on the market for Solar Renewable Energy Credits and how many we produce, we could then recoup an additional $2500 - $3000 per year.
Lastly, and really the smallest initial cost benefit, our energy bill would go down by a couple hundred bucks a month.
I've been looking into this for about 3 months now and will be meeting with a guy locally who recently installed a 6kW system at his house for $30,000. He's had no power at all for a year now.
I think that our country in primed for some big energy cost increases. Right now we're getting some "carrots" in the form of incentives to become more efficient but I'm afraid we're going to start getting the "stick" in the form of much higher rates soon.