Effect of thermal insulation of the back side of PV modules in the module temperature

The module temperatures of free-standing modules were compared with identical modules with thermally insulated back side simulating roof integration for 45° south orientation in Freiburg, Germany, at 1000 W/m2 solar irradiation. The thickness of the thermal insulation was varied in order to find a minimum thickness sufficient for suppressing the heat losses and for the simulation of roof integration. The module-dependent coefficients for the Faiman model for the module temperature depend on the back-side heat losses. A correction for roof integration is proposed. This model allows the calculation of the maximum temperatures reached for given climatic situations (irradiation in plane of array, ambient temperature, and wind speed).