I used SolarCity to finance, install and maintain. Not the cheapest solution, but they are taking care of everything for $0 out of pocket.

Of course, I'm going to be paying interest for decades (and the loan has to be paid off or transfer with my house if I sell), but it is approximately the same per kwh cost, just to SolarCity instead of my utility, plus I can pay it off if I wish.

Geez, on re-read, I didn't mean this to sound like an ad, but they make it so easy.

If you think you're capable of installing something flat on the roof that can withstand strong winds, and then wire it into your house electric wiring without causing a short and killing everyone, why not?

I can't imagine an average person doing this.

If you are going to connect to the grid you need a licensed electrician. If you are not connected to the grid you will need a large battery bank and twice the number of panels to get you through night and cloudy days. This is not to mention building codes and making your insurance company happy.