Getting less from your panels? Use your angles.
The angleTilt about equal to your latitude
For good output all year, tilt fixed solar panels at about your latitude, facing south in the Northern Hemisphere. If you can adjust them, go about 10–15° flatter in summer and 10–15° steeper in winter.
The video for this angle is on its way.
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How to do it
- Find your latitude. Most US homes are between 25° and 48°.
- For a fixed mount, set the tilt about equal to it.
- Face the panels south (north in the Southern Hemisphere).
- If adjustable: latitude minus 10–15° in summer, latitude plus 10–15° in winter.
- Keep them clear of shade. Shade costs more than a few degrees of tilt.
Your tilt
Rough US latitudes: Miami 26°, Dallas 33°, Denver 40°, Chicago 42°, Seattle 47°.
Why it works
Panels make the most power when the sun hits them straight on. The sun's average height in the sky depends on your latitude, so tilting to match it points the panels at the sun's average position through the year.
Questions
My roof pitch is different. Is that bad?
Usually not by much. Being within 10–15° of the ideal costs only a small share of output, and roof mounts are cheaper than tilting racks.
Which way should panels face?
South in the Northern Hemisphere. East or west faces still work but produce less.