Annual radiation falling on a tilted surface.
Example on calculating annual radiation falling on a tilted surface.
Test: For delhi city
p - 28.7
b - 30.1 % optimal tilt angle for maximum radiation
g - 0 % south facing
% monthly average sushine hours over a year
s_yr - [8.7, 8.7, 9, 9.7, 9.7, 9.4, 8.4, 7.8, 8.6, 9.6, 8.7, 8.1]
% Toal annual radiation on tilted surface.
yearly_rad(p,b,g,s_yr) radiation in KWh/m^2