Investigation of optimum monthly tilt angles for photovoltaic panels in tripoli through solar radiation measurement

Solar energy generation systems performance have always been noticed being affected by the changes in atmospheric conditions, temperature variations and angles of inclination where a PV panel's maximum output power depends on them. This paper aims to maximizing the output power of a PV panels by choosing an optimum tilt angle for each month of the year based on solar radiation measurements which have been measured and recorded by the Center for Solar Energy Research in Tripoli, Libya. Logging devices were placed at angle horizontal to the PV panel and recorded radiation data every ten minutes. The measurements were done over a period extended from January to December where a set of optimum tilt angles have been recorded for each month ( 60, 55, 45, 25, 20, 20, 20, 20, 20, 35, 45, 60) respectively. The results showed that the tilt angle 30 is the optimum angle by achieving a maximum solar radiation incident on the panel's surface, and two seasonal optimal angles 50 & 20 have been chosen for winter and summer months respectively for ensuring optimal performance of a PV panel.