Md. Mahdi Islam, Mahadi Hassan Fahim
It is important to determine the tilt angle of photovoltaic (PV) panels correctly if we hope to get maximum solar energy. This study mainly focuses on finding the optimal fixed and seasonal tilt angles for solar panels in all districts of Chattogram Division, Bangladesh. Using standard solar geometry formulas, we calculated important parameters such as declination, solar altitude, zenith angle, air mass, irradiance and daily solar radiation for each day of the year. Several fixed tilt angles (ranging from 1° to 40°) were tested to find the one that produced the highest total annual energy, which was identified as the best one. Also two seasonal tilt angles – one for April to September and the other for October to March – were identified to improve energy production and maximize solar energy. Comparison between hilly and flatland districts showed clear differences in the optimal angle and energy production. The results confirm that both latitude and terrain influence the best tilt angle. This work can help to better manage PV panel installations across Chattogram and support solar energy plans across Bangladesh.