Shading loss

[Abdel]

Hi,

It seems that PVsyst has wrong assumption but I hope to finds an answer from PVsyst team for my question

I have system of 10.4 KWp and inverter of 10KW. The system consists of 2 PV strings and the inverter has 2 MPPTs , which means each PV strings will be connected to one MPPT.

I have made shadow on one PV string caused by tree and another PV string is free of shading. Now in Module layout when I want to see the shading losses for each string, it seems PVsyst consider the system as one MPPT because PVsyst gives me 5% of electrical loss for unshaded PV string and this clearly wrong for the calculation and final results.

Now my question, Why PVsyst gives me 5% as electrical loss for unshaded PV string? is it wrong assumption ?

[Bruno Wittmer]

The screen shot from the module layout window does not correspond to the situation on the first screen shot of the 3D editor.

You have to set the date and time to the same hour in order to get the corresponding calculations.

Please check for which timestamp exactly you get the conditions of the first image, and then set the date and time accordingly in the module layout window.

The results in the screen shot of the module layout window seen consistent. The two strings are clearly on separate MPPT inputs, and both strings are partially shaded.

[Abdel]

The two strings are clearly on separate MPPT inputs, and both strings are not partially shaded. the shading is made just for PV string 1 and the another string 2 is free of shading but the system still gives electrical loss for it !!!

The time is the same for 3D editor and Module layout which is 21/12/2011. It is very strange that why PVsyst considers the system as one MPPT . 

Please can you give explanation about that ?

[Michele Oliosi]

The time of your lower screenshot is 16:15, while your 3D scene seems to have time around 2-3 pm.

Please use this tool to set the right time in the 3D scene. Once the time is set, click on "apply".

Please let us know if this improves the situation.