Optimum tilt angle for solar collection systems

For non-tracking solar collection systems, the tilt angle has a predominant effect on the quantity of energy that the system can intercept. In the present work, a computational algorithm is developed for the calculation of the optimum tilt angle that would orient a non-tracking solar collection system (concentrating or non-concentrating) in its best position for the maximum average daily, monthly seasonal or yearly intercepted radiation. The optimum tilt angles were obtained for latitudes ranging from 10-50 °N on monthly, seasonal and yearly bases. A case study is applied on Riyadh City (latitude 24.9 °N) to investigate the sensitivity of intercepted radiation when the tilt angle varies from that of the optimum value. The results show that, on a monthly basis when the collector is mounted at the yearly optimum tilt angle, the loss of radiation intercepted is less than 10% as compared to the monthly optimum tilt angle. The optimum seasonal tilt angle reduces the incident radiation by less than 2% from that of the monthly optimum tilt angle.