My personal belief is that solar and wind have their place. For it to be cost effective for any individual situation, you MUST gain as much understanding as possible in regard to the real installation, operational and maintenance costs. Just like you should do when you purchase a new piece of equipment.
I see them on many roofs around here. Here in Ohio they should facing directly South and angled 26 degrees in winter, 50 spring and fall, 74 summer. (vertical is 0 degrees) I know for a fact that none of the roofs these panels are mounted on meet those specifications. YES they will still make some power, but the further you are from those numbers, the further your panels are from producing their advertised output.
I have thought about setting-up a small system, just large enough to run some essential systems in the event of a power outage. Our rural utility was not very reliable. The longest outage was 2 days, but a few hours was a 5-6 times a year event. I was just about ready to install a small system when the utility began a major upgrade. At that point I could not justify the cost. A small generator I picked up cheap, because it would not run, has been working for me for over 15 years now.
If I was going to install one the panels would not be on the house. They would be free standing. Storage would not be in or mounted on the side of the house. It would be outside close to the panels.
Here is a link to a good place to get information on solar systems. This link sells a book, but you can get a lot of information from the link. There are online calculators you can use to see how your site should be set up, worksheets to help determine how much power you need to generate for your needs, how much storage capacity you need to have to get though the night and a few sunless days, etc
One final note, my fireman friends are not at all fond of solar systems mounted on roofs and storage banks on or in houses.
Solar can be a good thing, or a very costly toy. Do your homework. KNOW what you are talking about before you get a slick salesman to oversell you a system that does not work for you.
Solar Electricity