How to evaluate shading electrical losses with thin film modules ?

[André Mermoud]

In thin film modules, each cell is a strip of about 10 mm width, usually on the full size of the module.

Now in shading situations, you should put the strips perpendicularly to the potential shades. In this way the shades will affect all the cells of each module in the same way, so that there is no electrical mismatch.

Therefore the "Linear shadings" are representative. With thin film modules you should not use the "Partition in Module strings" nor the "Module Layout" options when calculating shading losses.

By the way thin film modules usually don't have internal by-pass diodes (no submodules), there is only one diode for the full module.

NB: The strips may be along the little or the longer side. This information is not included in the database of PVsyst, you have to refer to the datasheets.

This is important for deciding if you put your modules in portrait or in landscape.