Solar panel angle in Düsseldorf
In Düsseldorf, fixed panels collect the most energy over a year tilted 42° from horizontal and facing south. But anything between 30° and 50° is within 2% of the best, so the pitch you already have is probably fine.
What is your roof worth?
Every roof, scored
Percentage of the maximum possible annual yield, for each combination of orientation and pitch in Düsseldorf.
| Roof faces | 0° | 15° | 30° | 45° | 60° | 90° |
|---|---|---|---|---|---|---|
| South | 80% | 91% | 98% | 100% | 96% | 73% |
| South-east / south-west | 80% | 88% | 92% | 91% | 87% | 67% |
| East / west | 80% | 78% | 75% | 70% | 64% | 50% |
| North-east / north-west | 80% | 68% | 56% | 46% | 39% | 29% |
| North | 80% | 64% | 48% | 35% | 24% | 20% |
Why "tilt equals your latitude" is wrong here
The rule of thumb says tilt your panels at your latitude — 51° for Düsseldorf. The real optimum is 42°, 9° lower than the rule suggests.
Two reasons, both geometric. Summer days are much longer than winter ones, so the year's energy is weighted toward a higher sun than the annual average. And a low winter sun sends its light through a long slant of atmosphere, arriving weak — tilting to catch it costs more in summer than it wins in winter.
In fairness to the rule: following it here would cost you only 1.2%. It is wrong, but it is not expensive.
Seasonal angles
If you can adjust your panels twice a year, these are the angles to use. Most people should not bother — the gain is small and the ladder is real.
| Setting | Tilt | Facing |
|---|---|---|
| Fixed, all year | 42° | south |
| Summer | 23° | south |
| Winter | 70° | south |
| Flat on the ground | 0° | — |
A flat installation here keeps 80% of the maximum; mounted vertically on a wall, 73%.
Other cities in Germany
Assumptions
- These are angles and percentages, never kilowatt-hours. Optimal angles are driven by geometry and are robust. Absolute energy output depends on measured irradiance, cloud, soiling and hardware, none of which are modelled here.
- Clear sky, no shading. Trees, chimneys, neighbouring buildings and terrain are ignored, and they can dominate everything on this page.
- Fixed panels. Trackers follow the sun and change the answer entirely.
- Ordinary ground. Reflectance is taken as 0.2, typical for grass and soil. Snow reflects far more and favours steeper tilts.