Design optimization of photovoltaic(PV)array optimum tilt

In this paper, the method of irradiance on horizon change to irradiance on PV array is analyzed. The two PV systems which in same latitude but different irradiance resource and irradiance ingredients are simulated in order to got the optimal tilt of PV array. the tilt of PV array should chosen from 0° to local latitude. In direct irradiance abundant region, the tilt should be increased. In diffuse irradiance abundant region, the tilt should be decreased.