Location data · North Rhine-Westphalia
Sun hours in Gronau
How sunny is Gronau? Over a year the sun delivers 1,262 kilowatt-hours onto every square metre here — in June roughly 5 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 3.46 peak sun hours per day in Gronau. In 9 out of 10 years at least 1,203 kWh/m² are reached. All values are computed from this location’s satellite hourly data, not estimated.
- Annual average (PSH)
- 3.46 kWh/m²/d
- P90 annual total
- 1,203 kWh/m²
- Optimal tilt
- 40°
- Terrain horizon max.
- 1.1°
Sun hours per month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSH/day (35° south) | 1.16 | 2.08 | 3.48 | 4.88 | 5.16 | 5.41 | 5.24 | 4.80 | 4.00 | 2.67 | 1.54 | 1.01 |
| P90 | 0.89 | 1.58 | 2.93 | 4.01 | 4.28 | 4.78 | 4.68 | 4.25 | 3.41 | 2.03 | 1.19 | 0.72 |
Daily average per month in kWh/m² at 35° tilt, south-facing, including the terrain horizon of Gronau. P90 = reached in 9 out of 10 years.
Optimal tilt angle in Gronau
The annual optimum for Gronau is 40° south; anything between 25° and 52° counts as equivalent (below 2% difference). For winter operation (off-grid) 65° is optimal, for summer use 20°. Flat-laid modules lose 15.6 % versus the optimum. Adjusting twice a year would add 3.0 % here, monthly adjustment 3.8 % — only relevant for adjustable mounts.
Is a balcony solar kit worth it in Gronau?
A vertical south-facing railing in Gronau harvests 916 kWh/m² per year — 73 % 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 113 % of the 35° December value, computed from the same hourly data with its own plane transposition. Open the balcony solar calculator with these coordinates →