Algorithms For Estimating Yearly Sunshine Hours On Surfaces Of General Orientation

Algorithms which estimate the average apparent sunrise and sunset hour angles for winter and summer separately developed in the present article are general enough for non-south facing surfaces as well from which estimation of the yearly sunshine hours is straightforward. The effectiveness of the present algorithms and the inadequacy of the equinoxial day approach in calculating the yearly average tilt factor for beam radiation have been demonstrated for equator facing surfaces.