Figure 9
The seasonal contribution to the annual beam and sky-diffuse insolation on tilted surfaces. Based on real-sky results obtained with the modified Liu and Jordan model[35] and ERS data. For surfaces with slope (tilt) β and azimuth angle (deviation from south) γ. B + D insolation values of 4,310, 4,790, 4,830, 2,800, and 2,890 MJ/m2/ year for the respective orientations.