Navigation:  Project design > Shadings > Calculation and Model > Shading factor table

The Shading Factor is the shaded fraction of the PV field with respect to the full sensitive area, for a given sun orientation  (values 0 = no shades, 1 = fully shaded).

In the 3D construction, the shading factor is a complex calculation which sometimes spends too much time to be performed at each step of the simulation. See Beam Component for a detailed description of this calculation.

Therefore the program builds a table of pre-calculated values in sun's height (10° steps) and azimuth (20° steps), in which we can interpolate for getting the Shading factor for any sun's (or space) direction.

In a project, we have to establish a table for each orientation, and also for the scene of string rectangles if the option "shading according to strings" is activated.

With tracking systems, PVsyst established tables for different tracker's positions, for the evaluation of the Shading factor on diffuse for each position.

This table is used:

- for the calculation of the integral of the shading factor for diffuse and albedo components,

- for establishing the iso-shadings diagram,

- at each step during the simulation when choosing a fast calculation.

For not too big systems, the calculation of the shading factor can be fully performed at each simulation step to avoid interpolation errors (option "Slow calculation").

NB: During the elaboration of the shading table, the points (sun's positions) located behind the plane of the PV field appear in blue.

 

The Shading table provides a complete analysis of the shading scene. Some other software use this table (exported from PVsyst) for their own simulations.