How to set Ground Coverage Ratio for non flat surfaces (tilted roof)?

I know that GCR is used to calculate some land cost etc., but I want to know how to calculate for non flat roofs, or this doesn't impact the self shading calculus?.

I have a tilted roof surface faced to southeast, about 10° of inclination. The modules are in parallel to the roof, but in the articles I just found the formulas for flat surfaces on the ground ( REFERENCE ARTICLE ).

SBR = d/h, where d is the distance between the subarrays and h i the height of the modules
GCR = 1 / (cos(beta) + (SBR + sin(beta))), beta is the tilt angle from the FLAT surface and the module

The GCR values are from 0.01 and 0.99, I used 0.99 assuming there's no inclination from the roof to the modules subarrays, and the distance d between the subarrays are minimum.

Hi Leandro,

The ground coverage ratio (GCR) is a way to describe spacing between rows of tilted modules (either roof- or ground-mounted), when modules in adjacent rows can cast shadows on each other depending on position of the sun.

For an array of modules that are all in the same plane, such as on a tilted roof, the modules do not cast shadows on each other, so the GCR is not relevant.

Best regards,
Paul.