I put solar panels on my place, I went from about $900-1000 a year in electric to about $150-200. Winters here don't have much daylight so I make minimal power 4 months a year. Summer does make up for that with 20+ hrs of daylight though.
With the tax credit I have about $7k out of pocket into it, so payoff in around 9 years. The panels and inverters have a 20 or 25 year warranty I believe.
I would have pretty much free power but the electric company changed how they handle it. When I first looked into it, they did "net metering" where if you made more power in a month they you used, you would get a credit of x Kw/Hr for that month. So you could "save up" and in winter be all set. Well by the time I had everything bought, put up and inspected by them, they changed it where they buy back each month at wholesale cost. I pay about 0.16 $Kw/hr, they buy the extra power back at $0.04
Also at the time I had to put the panels only in one spot (power company didn't want a "split system" and wanted it on the main building.
Well my homeowners wouldn't cover any damage to the roof or secondary damage so I decided to put the panels on an outbuilding after working through a bit of red tape with the power company.
The shed is pretty much running in an east-west so the roof sides face the north and south.
I expected the north side to not make as much power... Well it's roughly 1/2 from the south panels.
I'm hoping to put those 8 panels on the house's south roof this summer.