📐 Tilt Angle Calculator
🎯 OPTIMAL FIXED TILT ANGLE
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Optimal tilt angle for maximum irradiance
The optimal tilt angle for a fixed solar panel equals the latitude of the installation location for maximum annual energy yield. For India, this ranges from about 8° (Kanyakumari) to 35° (Ladakh). Pune is at 18.5°N, so a 18–19° tilt is a good starting point.
For summer optimization, reduce tilt by 15° from latitude. For winter optimization (more useful for cold regions), add 15°. In most of India, a fixed tilt equal to latitude performs within 5% of a tracking system for annual yield.
The panel should face true south in the northern hemisphere (not magnetic south — account for magnetic declination). A 10° deviation from south reduces output by less than 1%, but a 45° deviation can reduce output by 5–10%.
| City | Latitude | Optimal Tilt |
|---|---|---|
| Mumbai | 19.1°N | 18–20° |
| Pune | 18.5°N | 18–19° |
| Delhi | 28.6°N | 28–30° |
| Bengaluru | 12.9°N | 12–14° |
| Chennai | 13.1°N | 13–15° |
If you can adjust the tilt twice a year (many rooftop mounting systems allow this), set a steeper angle in winter (latitude + 15°) and a shallower angle in summer (latitude − 15°). For most of India, the monsoon season (June–September) has low irradiance regardless of tilt, so the adjustment matters most for the October–May period.
On flat roofs, avoid tilt angles below 10° — the panel self-cleaning from rain is poor at shallow angles, and dust accumulation in Indian conditions can reduce output by 15–25% over a few weeks without cleaning.