Faiman Module Temperature Model

David Faiman presented a module temperature model (Faiman 2008) based on simple heat transfer concepts.  The model form is:

$$T_{m}=T_{a}+\frac{E_{POA}}{U_{0}+U_{1}\times WS}$$


  • $$T_{m}$$ is module temperature (°C)
  • $$T_a$$ is ambient air temperature (°C)
  • $$E_{POA}$$ is the irradiance incident on the plane of the module or array ($$W/m^{2}$$)
  • $$U_0$$ is the constant heat transfer component ($$W/m^{2}K$$)
  • $$U_1$$ is the convective heat transfer component ($$W/m^{3}sK$$)
  • $$WS$$ is wind speed (m/s)

In his paper, Faiman measured irradiance, wind speed, and module temperatures on seven different types of modules and fit the data to values of $$U_0$$ and $$U_1$$.  Note that all modules had front glass covers and Tedlar® backs.

  • Values of $$U_0$$ varied from 23.5 to 26.5 with a combined fit = 25 $$W/m^{2}K$$
  • Values of $$U_1$$ varied from 6.25 to 7.68 with a combined fit = 6.84 $$W/m^{3}sK$$