Fraction for electrical effect

[Tariq]

Dear PVsyst community,

After defining the electrical partition in the 3D model, the question is which fraction to select for electrical effect. I have read that the 100% is to be taken for regular shading. Could you please explain better what is meant by regular shading in this sense and what fraction to take for PV systems with surrounding trees and row shading of about 2-4%. 

Is there an option where you can define strings in the partition that are distributed across different tables?

Many thanks 

[Michele Oliosi]

If you need to distribute strings over multiple tables, you can only do that with the module layout.
At the moment we do not support partitions on multiple tables.

I would advise the following: run the module layout once to get an estimate of the electrical shading factors. If your scene is too large, you can create a smaller scene with similar shadings.

Then when using the partitions, start by defining 100% for the electrical effect fraction. If you see that this overestimates the shadings compared to the module layout, you can reduce the fraction. Apart from that there is no failproof way to define the electrical shading fractor whenever you have both regular (row-to-row) and complex (e.g. trees) shadings.

[Tariq]

Thank you for your reply. I have the following situation with Tracking system single Axis N-S and half-cut modules. On each tracker-table should be 1.5 String. Since the modules are planned as portrait, I have modified the string-number from 1.5 to 3. Could you please check if this is fine? 

 

[Michele Oliosi]

Hi, you should rather put 2 rectangles in X. It is not really possible to define 1.5 string per table, but since (I assume) all your strings will be submitted to similar regular and longitudinal shadings, the distinction between the full and the half string will not matter for shadings. They will probably be shaded in the same way.