7.4.6 - Bottom cells shading

[Miguel Rodriguez]

Hi all!

The situation is the following: I am running a test on backtracking with larger panels, and evaluating the impact that it would have if we don’t change the backtracking parameters. In this case, the panels would be approx. 2.3 cm longer than what the backtracking is configured for.

To evaluate this, I've just created a simple 3D scene with array of trackers, and disabled Automatic under the Bactracking Management window. Then I changed the collector width to be 2.3 cm smaller than the actual panel. This causes a small, constant shading on every panel (the configuration is 1 in portrait) during the backtracking period.

I used the same project file on two computers: one with PVsyst 7.4.5 and another with 7.4.6. I got two wildly different Electrical Shadings values. In 7.4.5 I got -7% and in the other -0.5%. The former seems reasonable (since all bypass diodes should be active during backtracking).

In the patch notes it says that you were changing the bottom cell shading behaviour on non-rectangular tables (mine are rectangular). Could it be detecting my arrays as polygonal?

Please take a look at the pictures below for further clarification.

PVsyst 7.4.6:

PVsyst 7.4.5:

 

Thank you!

[laurahin]

This is a known problem with v. 7.4.5 that has been corrected in 7.4.6.  There should be many other posts on this topic on the forum.

[Michele Oliosi]

On 5/23/2024 at 11:52 PM, laurahin said:

This is a known problem with v. 7.4.5 that has been corrected in 7.4.6.  There should be many other posts on this topic on the forum.

Indeed, thanks for the answer ! 7.4.6 is correct, i.e., a 2.3 cm imprecision will generally cause shadings shorter than a cell width, by which electrical shading losses are not so critical.