Location data · Rhineland-Palatinate
Sun hours in Speyer
How sunny is Speyer? Over a year the sun delivers 1,416 kilowatt-hours onto every square metre here — in June roughly 4 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 3.88 peak sun hours per day in Speyer. In 9 out of 10 years at least 1,323 kWh/m² are reached. All values are computed from this location’s satellite hourly data, not estimated.
- Annual average (PSH)
- 3.88 kWh/m²/d
- P90 annual total
- 1,323 kWh/m²
- Optimal tilt
- 35°
- Terrain horizon max.
- 2.3°
Sun hours per month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSH/day (35° south) | 1.53 | 2.60 | 3.91 | 5.19 | 5.40 | 5.85 | 5.80 | 5.32 | 4.66 | 3.09 | 1.83 | 1.31 |
| P90 | 1.24 | 1.99 | 3.01 | 4.25 | 4.59 | 5.09 | 5.13 | 4.70 | 4.07 | 2.52 | 1.46 | 0.90 |
Daily average per month in kWh/m² at 35° tilt, south-facing, including the terrain horizon of Speyer. P90 = reached in 9 out of 10 years.
Optimal tilt angle in Speyer
The annual optimum for Speyer is 35° south; anything between 24° and 51° counts as equivalent (below 2% difference). For winter operation (off-grid) 65° is optimal, for summer use 20°. Flat-laid modules lose 15.1 % versus the optimum. Adjusting twice a year would add 2.9 % here, monthly adjustment 3.8 % — only relevant for adjustable mounts.
Is a balcony solar kit worth it in Speyer?
A vertical south-facing railing in Speyer harvests 1,002 kWh/m² per year — 71 % 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
- Mannheim3.85 kWh/m²/d19 km
- Wiesloch3.89 kWh/m²/d20 km
- Heidelberg3.52 kWh/m²/d21 km