Albedo shading component calculation

[ClaireWest]

Hi, how is the albedo shading component (ShdALss) calculated? I have read the help pages on this topic but i am still not clear how this functionally works, sorry.

https://www.pvsyst.com/help/project-design/shadings/calculation-and-model/index.html

https://www.pvsyst.com/help/project-design/shadings/calculation-and-model/treatment-of-the-albedo-component.html#far-shadings

Why does the albedo shading loss have this profile on a clear-sky day (single-axis tracking system): ?

TIA

[Linda Thoren]

Hi,

The shading calculation is indeed explained in the second link you have attached. In general, the higher the tilt, the higher the albedo contribution. Most of the albedo contribution will directly be lost (you see that the albedo loss is indeed following the albedo contribution) since we assume that only the first row is "seeing" the albedo, so that the albedo shading factor will be (n-1)/n (n = number of sheds). The albedo loss is a significant contribution to the global shading losses.

[ClaireWest]

Thank you. Is that a fair assumption that only the first row is "seeing" the albedo? With typical GCR ~40% or lower there will be sun hitting the ground between the panels by early to mid morning. E.g. in my snip above (36% GCR), at 8am only 65% of the ground is shaded and at 9am only 48% is. So the albedo shading factor should be ~35% and ~52% during these times?