Module temperature

The module temperature Tm is calculated from the ambient temperature by the following formula:

Tm=Tamb+kTG (6)

This formula shows how the modules are heated up by the solar radiation. It is a very simple formula that doesn't take into account cooling effects such as wind. If your system is in a very windy area, this will reduce the temperature of the modules and this will help increase the efficiency a bit. The coefficient kT depends on the type of mounting used for the PV system. In general, a building-integrated system will be hotter than a free-standing rack-mounted system because the air cannot circulate freely around the back of the modules and cool the modules. In PVGIS we have used the following values:

   kT=0.035�C/(W/m2) for free-standing systems, based on measurements done at our laboratory
   kT=0.05�C/(W/m2) for building-integrated systems, based on values taken from literature 

Tm