Bifacial model when there is a single shed/array in the 3D scene

[Hung MAI]

Hello PVsyst team,

In PVsyst version 8.0.4, I was able to run this simulation where there are 5 different orientations (hence 5 sub-array in Systems), in which one orientation only include 1 big array of 26x19 modules.

But since version 8.0.5, I have this error when opening the above variant. I tried to manually defined the pitch & Number of Sheds in the bifacial model, pitch 26m and different sheds number 1/2/500, but the errors is still there.

I don't know how to solve this issue, maybe it is a bug since ver 8.0.4 can run it (although I understand the Diffuse Ground Factor will be 0 since the pitch is recognized as 0 by PVsyst in the bifacial model window, meaning it is less accurate?). But then the new function of defining the pitch&shed should have worked to correct this?

Also in the 3D scene & Orientation windows, there is no error or warning at all.

Can you help me with this? Thanks a lot!

[Michele Oliosi]

Hello !
The issue is that PVsyst is not really yet able to define a bifacial model when there is only a single table in the orientation.
While it may have seemed to work in previous versions, the calculation was probably not correct.

This issue will be solved in an upcoming patch.

Until now, the workaround to define a single table with a bifacial model was to put two tables in the 3D scene, and distance them enough so that there would be no shading between them. Here, since there are shading objects and other orientations, this is a bit more tricky. What I would suggest is grouping the single table from orientation 5 with those of orientation 3 (which have a very similar orientation). To do so, you can enter “Orientations management” and drag and drop the table from orientation 5 to orientation 3. If prompted, choose “create average orientation”. Another option is to go to the List and Management of objects (or CTRL+G) and simply use the drop-down menu to select the orientation 3 for this table.

By putting them in the same orientation, you will be able to define a single “average” bifacial geometry model.