The tilt angle of a solar panel is the angle between the plane of the solar panel and the horizontal plane. This angle is a critical factor in maximizing the efficiency of solar systems, as it determines how much sunlight the panel can capture.
Why is the angle of inclination important?
Maximum utilization of sunlight: The correct tilt angle ensures that the solar panel receives as much direct and diffuse radiation as possible, especially during peak solar radiation periods.
Optimizing energy production: Inadequate tilt reduces the amount of light captured by the solar panel, resulting in lower energy production.
Seasonal adaptation: Optimizing the tilt angle helps adjust the performance of the solar panel to the seasons, maximizing production in both winter and summer.
Optimal tilt angle
General rule: The optimal tilt angle is usually adjusted to the latitude of the installation location. In Hungary, the recommended tilt angle is 30–35°, as this is the most favorable in terms of annual energy production.
Seasonal tilt angles:
- Summer: The Sun is higher, so steeper angles (around 15–20°) may be optimal.
- Winter: The sun is lower, so steeper angles (around 40–50°) can help maximize sunlight.
Fixed vs. adjustable tilt angle:
- Fixed-angle solar panels are set to the annual average optimal angle.
- Adjustable systems allow for seasonal angle changes, further increasing energy production.
Effect of tilt angle on energy production
Angle too flat:
- It reduces the effective capture of sunlight, especially in winter.
- It can increase dust and dirt buildup, which reduces efficiency.
Too steep an angle: Reduces the amount of sunlight captured in the summer when the Sun is higher.
Optimal angle: The correct angle maximizes the utilization of direct and diffuse radiation, minimizing production fluctuations throughout the year.
Example calculation of the efficiency of the tilt angle
A 1 kW solar system in Hungary:
Optimal angle of inclination (30–35°): Annual energy production approx. 1100–1200 kWh .
Different tilt angle (15° or 50°): Annual energy production can be up to 10–20% lower than the optimal angle.
Summary
The tilt angle of the solar panel is a key factor in the efficient operation of solar energy systems. Determining and setting the optimal angle maximizes the utilization of direct and diffuse radiation, while minimizing energy production losses. In Hungary, the average annual optimal tilt angle is 30–35°, but an angle adjusted to individual conditions can result in further efficiency gains. Adjustable-angle or sun-tracking systems provide even greater energy production, especially under changing weather and seasonal conditions.