Annual solar irradiation on inclined surfaces

Select altitudes by dragging the red and green 'handles' on the map (may require some practice on tablets).

Annual irradiation at the selected altitudes:

Select inclination of surfaces (0° is horizontal):
Select direction of surfaces (if on southern hemisphere, read W-N-E):

90900000The calculations are based on an 'Air Mass'-model that takes into account the absorption of sunlight by the atmosphere.
It's assumed that the sky is clear.