Loss Parameters versus Loss Diagram

[JoeA]

Hello All,

I am trying to understand why the losses in the parameter settings are different compared to the losses in the loss diagram. I highlighted two examples.

I tried running a calculation to determine what the total LID losses are. My calculation to compare the LID losses is as follows:

43.12GWh * 1.60% LID loss = 0.68992GWh loss.

versus

43.12GWH * (1 - 0.2% Module Degradation Loss) * (1 - 0.54% Irradiance Level PV Loss) * (1 - 0.68% Temperature PV Loss) * (1.55% LID Loss) = 0.65891GWH loss

 

Could someone explain in greater depth how the loss diagram is calculating loss percentages?

Thank you!

[Michele Oliosi]

Hi,

The ohmic loss fraction is specified at STC in the project windows. This means that in case of different current and voltage conditions the losses may differ (ohmic losses go like the square of the current). In the loss diagram you have the average over the whole year, so considering many different conditions.

I think that for the LID loss this is just a rounding issue. 1.6% there probably stands for 1.55%. We will check this behavior in details.

Regarding the two calculations, the second one is correct. If you want a loss as an absolute value, you should consider the diagram flow and apply all the losses above the LID loss.