First of all, if the energy produced by a solar system covers around 80% of a the needs in a household, and you did install a very good model, then you will get all your money back through the savings you make from the electricity bill monthly. We could talk about free solar panels in term of a "re-funding" that the system works on your budget. The real return on investment when you create solar power is obvious within maximum two years in case of a very sophisticated and ultra modern solar system, or up to five years if you've purchased an average one. One great resource for making your own solar power is Homemade Energy by Bill Ford. You can read about it here Home Made Energy Review
In time, the savings you make by the use of renewable energy resources are huge so that you get to recover your investment and save a lot afterwards. This means that once the return on investment is no longer valid, your gain comes from the periodical savings that you make every month. The maintenance of the home solar panels is virtually nil unless you install some more sensitive devices such as a sun tracker. Keep in mind the fact that a good assessment of the situation is necessary before making the decision to add something further to the system.
Home solar panels should work well both in summertime and in winter, with the mention that you may have to modify the inclination angle of the panels, though this is not a rule. The changes summer-winter should be specified in terms of technical features in the very installation instructions you receive on purchasing the home solar panels. Moreover, a professional installation team should be able to give all the guidance you may need.
