Location data · Bern
Sun hours in Biel
How sunny is Biel? Over a year the sun delivers 1,482 kilowatt-hours onto every square metre here — in June roughly 3 times as much per day as in December. “Sun hours” has two meanings: the weather report counts how long the sun shines. For solar power what matters is how much energy arrives — and that is what this page shows, as peak sun hours (hours of full sun power).
For solar planning this means: an optimally tilted, south-facing array (35°) harvests an annual average of 4.06 peak sun hours per day in Biel. In 9 out of 10 years at least 1,367 kWh/m² are reached. All values are computed from this location’s satellite hourly data, not estimated.
- Annual average (PSH)
- 4.06 kWh/m²/d
- P90 annual total
- 1,367 kWh/m²
- Optimal tilt
- 35°
- Terrain horizon max.
- 36.7°
Sun hours per month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSH/day (35° south) | 1.95 | 3.11 | 4.25 | 5.13 | 5.13 | 5.83 | 5.85 | 5.41 | 4.80 | 3.42 | 2.11 | 1.69 |
| P90 | 1.53 | 2.25 | 3.09 | 4.00 | 4.41 | 5.04 | 5.15 | 4.72 | 4.24 | 2.78 | 1.66 | 1.38 |
Daily average per month in kWh/m² at 35° tilt, south-facing, including the terrain horizon of Biel. P90 = reached in 9 out of 10 years.
Optimal tilt angle in Biel
The annual optimum for Biel is 35° south; anything between 23° and 50° counts as equivalent (below 2% difference). For winter operation (off-grid) 65° is optimal, for summer use 20°. Flat-laid modules lose 14.9 % versus the optimum. Adjusting twice a year would add 2.8 % here, monthly adjustment 3.8 % — only relevant for adjustable mounts.
Is a balcony solar kit worth it in Biel?
A vertical south-facing railing in Biel harvests 1,039 kWh/m² per year — 70 % of what an optimally tilted 35° panel yields at the same spot. December softens the penalty: with the low winter sun, the vertical plane reaches 107 % of the 35° December value, computed from the same hourly data with its own plane transposition. Open the balcony solar calculator with these coordinates →
Neighbouring places compared
- Bern4.02 kWh/m²/d26 km
- Neuenburg4.20 kWh/m²/d29 km
- La Chaux-de-Fonds4.23 kWh/m²/d32 km