Changes in Uc & Uv result in increased mismatch loss

[Enginerd]

Hello Andre,

I have been playing with thermal loss constants Uc and Uv to address thermal losses in high elevation regions. I ran two simulations where the only difference was Uc and Uv. The second simulation, which had smaller values for Uc and Uv, produced an increased PV Loss due to Temperature (as expected) but is also caused Module Array Mismatch Loss to increase significantly. Can you please give a description of how the thermal properties would affect mismatch loss in the simulation calculations?

Thank you.

[André Mermoud]

This is explained by the fact that

- The mismatch loss is computed as a a percentage by respect to the STC power at each step.

- The result in the loss diagram is displayed as the percentage of the remaining energy after the preceding loss.

Therefore the reference is not the same so that the percentage changes between the parameter definition and the results.

In your case, when increasing the Thermal loss, you increase the difference between the STC value and the remaining energy.

NB: This calculation according to STC is not quite meaningful (it is an historical choice).

In the future version 6 the loss will be computed by respect to the remaining energy, so that the Loss result will correspond to the specified loss parameter.