Fixed tilted plane vs unlimited sheds

[Abdel]

Hi,

I have simple question which confused me a lot

What is the difference between Fixed tilted plane and unlimited sheds in PVsyst ?

in PVsyst help document, it mentioned for unlimited sheds that "the sheds are very long with respect to their width", so what does it mean also in this case by this sentence?

[dtarin]

For shading calculations by considering very long rows, unlimited sheds ignores edge effects. Modules on the edges of an array will have lower shading losses compared to modules on the interior of an array, which is what unlimited sheds captures. This has a tendency to produce less accurate shading losses compared to generating a 3D shade scene.