PV loss due to irradiance level

[Edward Li]

Hello, under what condidtions the PV loss due to irradiance level is 0%? Does it means that there is no any loss in low irradiance？  

[André Mermoud]

The  "loss" due to irradiance level is related to 2 factors:

• - The low-light performance of the PV module
• - The irradiance distribution along the period of simulation.

Please check the low-light efficiency of your module ( PV module dialog, page "Model parameters => Rshunt-RSerie", option "Rel effic" 😞

The default of PVsyst (reasonable for most modules) is -3% at 200 W/m2.

Now when distributing their own PAN files, most manufacturers set the Rserie parameter for boosting this  value, to -2% or even -1% . In this case you have a large part of the curve with positive relative efficiency, i.e. a gain during the simulation at high irradiance.