ORIENTATION OF SOLAR PANELS TO THE ELEVATION OF THE SUN: REVISITED

摘要

Whenever possible, solar panels are oriented exactly southwards and their angle of inclination is chosen as to give the highest yearly energy yield. The angle of inclination for highest yearly yields depends on the geographical latitude. In Switzerland it is around 25? If the inclination angle of the solar panel follows the elevation of the sun the separation of the panels has to be increased in order to avoid shadowing. Our investigation deals with the question, whether the same yield per unit area of the panel can be achieved with less solar cells if they follow the sun's elevation. In order to arrive at realistic data, we started an experimental investigation, which so far covered results and comparison of the daily yield of two panels with ten solar cells each. The cells of one of the panels could be oriented towards the elevation of the sun. First data show, that on sunny days end of August the yield increased by about 5% , and end of September by 18% over that of the panel with fixed inclination of the cells. However, in order to avoid shadowing, the panel with orientable cells had a by 30% larger area. Therefore, a decrease of the energy yield per unit area was observed by about 25% and 12% resp. Measurements in other months are required in order to allow conclusions on the yearly energy yield.