What does the white part of the Iso Shading Diagram representing?

[PVsystUser]

Please see the green rectangle in the screenshot below. What do the shading lines that fall inside the green square represent? That area is outside of sun path for the project's location;  why they have a specific shape if they don't have any meaning? 

[Muhammed Sarikaya]

Dear,

The multiple curves visible comes directly from the shading factor table.

See the help related: https://www.pvsyst.com/help/project-design/shadings/calculation-and-model/iso-shading-diagram.html

This table is computed on a fixed grid (20° azimuth / 10° height),when fast calculation is choosed, see the help: https://www.pvsyst.com/help/glossary/shadings/shading-factor-table.html?h=table+fa

And PVsyst always displays the isolines resulting from this calculation.

However, the solar path never enters this region of the diagram that your show in green rectangle.

Therefore, even though the iso-shading curves appear there, they do not correspond to any real shading situation. They are simply the graphical projection of the table-factor values in an area of the sun-position diagram that is never reached by the actual sun path.

Only where the iso-shading lines intersect the solar trajectories can real beam shading occur.

Regards,