Is it redundant to consider shading losses in irradiance and additionally include electrical shading losses?

[Angel David Duarte Moreno]

Hi all,

We are currently performing a technical comparison between PVsyst and HelioScope for a C&I rooftop project (FEMSA Coca-Cola case), and we observed that shading losses reported in HelioScope appear lower than those obtained in PVsyst.

In PVsyst, we are considering:

• Near shading irradiance losses (~3.5%)

• Additional electrical mismatch losses due to shading (~1.9%)

This leads to a relevant question from a modeling standpoint:

In HelioScope, are shading losses reported as:

1. Pure irradiance (geometrical) losses only?FEMSA_ Coca-cola_ Tocancipá_Project.VC1-Report.pdfFEMSA_ Coca-cola_ Tocancipá_Project.VC1-Report.pdfFEMSA_ Coca-cola_ Tocancipá_Project.VC1-Report.pdf

2. Or do they already include the electrical mismatch effects caused by partial shading?

From a methodological perspective, we are trying to understand whether including:

• Irradiance shading losses, and

• Additional electrical mismatch losses

could potentially lead to double counting in PVSyst, depending on how each software handles the shading model internally.

 

PVSyst results:

 

Helioscope results:

 

We would appreciate clarification from anyone who has experience reconciling results between the two platforms.

Best regards,

 

Angel Duarte

[Linda Thoren]

Hello,

As you indicate, in PVsyst you will first find the irradiance loss (linear shadings) and then the additional electrical shadings. Note that, in the loss diagram, each loss is defined as percentage of the previous energy quantity. Therefore the percent values are not additive.