[joshocar]

A lot of it comes down to the individual State incentives. My co-worker put in a system on his house and at the time the incentive was that you sold all of your power back to the grid at a fixed rate that was higher than what you would normally pay. He gets a check every month for what he sells to the grid. That rate was locked in for 15 years. It meant that he knew that with average usage he would break even in 6-7 years. Downside is that he is taxed on that income.

The other side of it is how big your roof and if it faces south without much occlusion. If your roof doesn't face south or is occluded but trees then it makes it much less attractive.