Solar panels will not pay for themselves in your lifetime. I know because I have some. They will increase the value of your home, reduce your bills, and be generally better for the environment, but the cost of the panels and installation is very high. I have only 6 panels and they (plus istallation) would be worth about 20,000 when I got them (I won them in a contest 8 years ago).
None the less, I still think solar panels are great, you can get small systems too, such as for emergency use or for an RV or Cabin. Check out this panel Sunforce 50033 15-Watt Solar Charging Kit
Otherwise the actual cost for your house depends on where you live and your power needs.