You should not consider investing in green energies unless you are ready to spend at least fifteen years in your home. Paying off your solar energy system will take you years and the return on your investment will depend on how long you stay in the same home and keep using the solar energy system.
Solar panels are not very easy to install, so you should hire a professional to get the job done. While you will save a bit of money by trying to do it in your own, you do not want things to be less than perfect. Also, you will most likely end up paying someone to come out and fix the mess you made.
There is really no reason to even consider getting a solar energy system if you live in an area that rarely sees the sun. This does not mean that a less than reputable company will not try to sell you a solar system though. If your roof does not receive at least 6 hours of full sunlight per day, you should not consider solar power.