In Polish conditions, it is assumed that the optimum roof pitch for PV installations should be between 30st.-40st. In southern regions, the proper roof pitch angles oscillate in the range of lower values (closer to 30st,) and in the north they are closer to 40st. However, the model roof pitch angle, which will give us good results, also depends on the direction of pv panels and season.
When the panels are placed southwards, the optimum roof pitch (30st to 40st) gives the best performance. With a pitch of less than 30 degrees we have less losses than with an angle of more than 40 degrees. On the other hand, panels that are inclined at a lower angle than 30 degrees produce more energy in summer than in winter.
If the installation is installed east-west, a larger annual energy yield will give us a slope of less than 30 degrees. In addition, it was found that with a lower slope, the installation starts working faster in the early morning than with a 30 degree system, given the east-west direction.
Therefore, to sum up, installations set up at non-standard angles (other than 30-40 degrees) generally give lower yields, with the southern arrangement of pv panels. On the other hand, the situation changes when the orientation changes, then we can adjust the slope of the installation to achieve not better efficiency by using non-standard slope. The roof pitch is particularly important in the production of electricity in winter and summer.