V.6 Loss Diagram, Shadings

[kamomeno68]

I've just adopted V.6 of the software, and am still trying to sort out the differences form V.5. The software help has answered most of my questions. One I can't seem to identify is change in the way the Shading losses are listed in the Loss Diagram. In V.5, there is only one line item: "Near Shadings". In V.6, there are two line items: "Near Shadings irradiance loss" and "Shadings: Electrical loss acc. to strings". In V.6, is the loss diagram simply splitting out the impact of shading into two components, a "linear" portion and a "strings" portion? Are these two together equivalent to the "Near Shadings" loss listed in V.5?

[André Mermoud]

Yes it is exactly this idea.

The "Linear shadings" loss corresponds to the Irradiance deficit on the modules. Therefore it is reported as an Irradiance loss.

The "Electrical effect" is the electrical shading loss due to mismatch. It may be computed either using the "Module layout" option ("exact" calculation), or approximated by the old "shading loss according to module strings" (which gives an upper limit to the electrical shading effect); in the latter case it is the difference between the full loss "according to strings" and the linear loss (weighted by the "Fraction for electrical effect" parameter). This loss is related to the array electrical behaviour, and is therefore accounted in the Array losses.

In the version 5, these 2 contributions were gathered in the Irradiation loss.

The "Module layout" calculation gives the opportunity of evaluating the "Fraction for electrical effect" parameter, which was just like a rabbit pulled out of the hat in version 5.