RMS value Mismatch losses

[Barbadori]

Hi there,

I would like to know how it's calculated the RMS value (%) when using the detail computation on the mismatch losses. I've been told that it's the power tolerance divided by the power output of the module but the results I get don't make any sense.

Could anyone help on this please?

Many thanks in advance.

[André Mermoud]

The RMS of the Isc and Voc values is not a calculation, but an hypothesis (input parameter) for this pedagogic calculation tool.

This allows to define a distribution in a simple way.

Logically, this should indeed be related to the the tolerance of the PV modules sample defined by the I/V measurements performed at the output of the facory, and which can sometimes be obtained from the manufacturer. Applying this value leads indeed to very low Mismach losses.

However in the reality, the dispersion is probably much higher, due to the quality of the Factory's flast tests instruments (their accuracy cannot be better than around 3%), differences in LID or soiling, etc. See our FAQ How to define the Mismatch loss parameters ?, differences after LID, etc.