IAM

[antreas]

Dear all,

could you please specify how PVsyst calculate the reflection losses of the diffuse radiance (IAM factor on sky diffuse). Alsow FIAM of equation is losses or is the radiance to ends up to PV cell??

[André Mermoud]

The calculation of the IAM loss on diffuse is based on the hypothesis that the Diffuse is isotropic. This means that the diffuse irradiance contribution is the same whatever the direction of the sky.

Therefore we can calculate an integral of the IAM loss (function) over all the sky directions "seen" by the collector plane. This integral is independent on the sun position, as well as the goegraphic location. This is a constant value, only dependent on the system geometry.