Best solar panel angle by latitude
If you only know your latitude, the table below is a good start. It assumes clear skies; real climates with cloudy winters push the year-round optimum a few degrees lower, which is why the calculator above uses measured sunlight for your point.
| Latitude | Year-round | Summer half | Winter half | Off-grid (worst month) |
|---|---|---|---|---|
| 0° | 0° | 0° | 21° | 0° |
| 5° | 4° | 0° | 26° | 3° |
| 10° | 9° | 0° | 31° | 10° |
| 15° | 14° | 0° | 36° | 16° |
| 20° | 19° | 0° | 40° | 23° |
| 25° | 24° | 3° | 45° | 30° |
| 30° | 28° | 8° | 49° | 38° |
| 35° | 33° | 13° | 54° | 46° |
| 40° | 37° | 18° | 58° | 57° |
| 45° | 41° | 23° | 62° | 68° |
| 50° | 45° | 28° | 66° | 75° |
| 55° | 48° | 33° | 69° | 78° |
| 60° | 50° | 38° | 72° | 81° |
| 65° | 51° | 42° | 73° | 69° |
What the rules of thumb get right — and wrong
"Tilt = latitude" is close for a year-round optimum between about 25° and 40° latitude and too steep further north, where summer's long days carry most of the yearly energy. At 52° N the year-round optimum from climate data is usually 36–40°, not 52°.
"Latitude ± 15°" for winter and summer points in the right direction, but the winter figure is often too shallow for off-grid use. The winter-half optimum at 50° N is around 60°; the tilt that maximises December alone is 70–78°.
A few degrees rarely matter. Near the optimum the yield curve is flat: ±10° typically costs under 3% of the yearly total. Roof pitch is usually good enough for grid-tied systems. It is off-grid systems, sized for one month, that are sensitive to tilt.
Orientation: south, east–west or something between
Facing the equator gives the most energy for a given tilt. East- or west-facing panels lose roughly 15–20% of the yearly total at moderate tilts, but spread production over the day — useful when the energy is used on the spot. In winter the loss of an east or west orientation is much larger, because the low sun spends most of the day in the southern sky.
Adjusting the tilt through the year
The calculator shows what twice-yearly and monthly adjustments gain. For most places two positions — a summer and a winter tilt, switched around the equinoxes — capture most of the benefit of monthly changes. Tracking the sun with a motor gains far more but costs far more.