Solar Panel Tilt & Azimuth Calculator

A fixed solar array collects the most energy when it faces the sun squarely, and the single best year-round compromise is to tilt it up from horizontal by an angle equal to your latitude. A site at `40°` north wants panels tilted about `40°`. This aims the array at the sun's average height across the seasons, which is why the latitude rule is the standard starting point for a fixed mount.

The sun rides higher in summer and lower in winter, so the tool also offers seasonal settings. Subtracting about `15°` lays the panels flatter to catch the high summer sun; adding about `15°` stands them steeper for the low winter sun. If you can adjust your mount twice a year, those two settings noticeably beat a single fixed angle; if you cannot, the latitude angle is the one to build.

Direction matters as much as tilt. In the northern hemisphere the array should face true south (`180°`); in the southern hemisphere it faces true north (`0°`). Note that this is true, not magnetic, south — correct for your local magnetic declination when you aim it. Shading trumps all of this: a perfectly tilted panel in afternoon shade loses more than a slightly off-angle one in full sun.