Optimal tilt angles for solar collectors facing south at Fez city (Morocco)

The main objective of this paper is to determine the optimal tilt angles for south-facing solar collectors at Fez city in Morocco. This is this would allow collectors to receive the maximum of the incident solar energy. Thirteen models were used to calculate the global solar radiation reaching an inclined surface facing south. To determine the optimal tilt angle we varied the inclination angle from -20° to 90° by a step of 5°. The performances of each model are evaluated by comparing the calculated and measured global solar radiation on a surface facing south and tilted by 34°. Results of the best found model show that the optimum tilted angle is varying between 62° (December) and -6° (June). Also, the yearly-average optimal tilt angle is found to be 32° for Fez. Keywords: Optimum tilt angle; global solar radiation; diffuse solar radiation; Fez (Morocco)