Do not put solar panels in the shade!

Here is one example of how NOT TO do solar array installation on the roof that is severely shaded by nearby trees. This solar installation will have its energy production and electric energy output into the house severely reduced because of the shade made by the trees in the yard.

http://www.greenbeltsolar.com/solar_shading_article.html

 As you can see, the solar panel array on the left side of the roof is all but completely useless in making electrical energy and it's impact for this house energy production is very minimal. On the right side only one panel (one too many!) on the lower left is affected by the shade. The shade will move from panel to panel as the sun moves across the sky thus affecting the whole installation.