Irradiance near Edges

i’m wondering about some results of an annual irradiation calculation (LBT 1.7.1). Near the edges the irradiation is significantly higher then on the average of the surface:

The difference from points near the edges is up to 400 Wh/m² a year:

Can this be reduced by some radiance parameters?
Irradiation (62.6 KB)

Best regards,

@HeikoWoehrle Hi, is you geo a closed brep? Try to join the surfaces and decrease the grid size a little more