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Solar Panels: Do They Need to Face South?

 Many customers are happy to learn that solar panels don't need to face due-South.

Many customers are happy to learn that solar panels don't need to face due-South.

Science, yes science, tells us that it's best to face solar panels to the South because you'll get the most bang-for-your-buck with the investment you've made. But won't they work if they face East or West, or what about North?

The truth is that while solar panels that face East or West (or North) are not ideal, it can make economic sense for many customers. Panels facing East or West produce about 15% less electricity than the same panel facing South, and with panels facing SE or SW, that number is only 7%. And while we typically have better options than facing panels toward the North, with a shallow tilt angle you might only lose 20-25%.

In general, the best tilt angles are between 20 and 45 degrees, which also happens to be the pitch of almost all residential roofs in Wisconsin. A lower tilt angle will give you more solar output in the summer when the sun is high in the sky, but less in the winter with the sun is low. And vise versa for a steeper tilt angle. If you're building a structure for solar panels, you're best bet is to construct a roof pitch of 30-35 degrees, giving you a nice balance between summer and winter sun angles, and it's also enough to shed the snow more quickly.