Optimizing solar-thermal collector's angles to enhance useful energy gain

To enhance useful gained energy by solar thermal collector, two software programs are used for optimizing tilt and incidence angle of the collector. TRNSYS program is used to predict solar useful energy gained by the collector. The Design-Expert (DOE) tool with response surface methodology (RSM) program is used to optimize the tilt angle. Results show that tilt angle and the incidence angle have important effect on the gain of the useful energy. In addition, it is shown that the optimum tilt angle varies monthly or seasonally. Moreover, to get maximum useful energy, the incidence angle has small angle around 10° and almost stable throughout the seasons. The optimal tilt angle has lowest value in summer and the highest value in winter. The calculated values are of 39.57°, 26.72°, 20.15°, and 32.2° and the corresponding maximum monthly averaged useful energy gained by the collector in January, April, July, and October are 223.52 kWh, 482.61 kWh, 596.56 kWh, 386.51 kWh respectively.