which irradiance to compare with pyranometer data

[jimbob22]

Hi we are diagnosing issues on a site.

When comparing measured irradiance from an in plane pyranometer which the predicted values from PVsyst, which of the PVsyst predicted values should we use for comparison?

GlobInc or GlobEff?.

Thank you

[André Mermoud]

GlobInc is the irradiance on the plane, calculated by the transposition model.

GlobEff is the irradiance effectively falling on the PV modules, after optical losses like shadings, IAM or Soiling.

You should compare with GlobInc of course.