Solar energy yield - optimum tilt angle PV array
Solar energy yield - optimum tilt angle PV array

Tilt angle - PV array

The tilt angle of the photovoltaic (PV) array is the key to an optimum energy yield. Solar panels or PV arrays are most efficient, when they are perpendicular to the sun's rays.


The default value is a tilt angle equal to the station's latitude plus 15 degrees in winter, or minus 15 degrees in summer (1). This normally maximizes annual energy production. 

However, through out the year the sun's path and the solar altitue vary.  In europe for example the solar altitute during summer reaches 60°-65° whereas in winter solar angles are as low as 13° - 18°.


To optimize capture of solar panels a tilt angle of 28° - 30° is recommended. However, tilt angles between 20° - 60° are possible without great yield losses. Increasing the tilt angle favors energy production in the winter, while decreasing the tilt angle favors energy production in the summer.


Find out the sun path and solar altitude for your U.S. location. 

Click here » Sun path 




Calculate the roof angle - roof pitch

PV Dachneigung berechnen / ermitteln
Rise / height (A) in inch*
Run / lenght (B) in inch*
roof angle (β) °
*The conversion is pretty easy. Just take the lenght B as show in the picture and find it's corresponding height A. The calculator will do the rest. In the United States, slope is typically given in inches per 1 foot. In Europe roof pitches given in degrees (°) are inclinations. Be careful with this method as a roof may consist of multiple layers of tiles and insulation, or roofing that is irregular. This can lead to less precise results. The results are for information only and can only serve as an indication. No guarantee. For more information send us an E-mail.