Solar Irradiance

I would love to see an overlay which depicts the solar irradiance at the surface (W/m^2), assuming a clear sky but taking into account the aspect/slope angle of the terrain. The user would be able to select the date/time depicted. This would extend the functionality of the "Sun Exposure" overlay, which only displays binary information (if the solar irradiance is 0 or >0), and the "Point Info/Sun and Moon Info" which shows similar information but only at a single selected point.

The cumulative solar irradiance at the surface (W*hr/m^2) could also be calculated for a user-specified time period.

A graphical depiction of this information in your mapping application would be very useful for (potential applications in parentheses) depicting solar contribution to e.g. vegetation drying (wildland firefighters), snowmelt (avalanche forecasters, backcountry skiers), and diurnal surface temperature variation (light aircraft/glider pilots).