simulation of low irradiance conditions (how to adjust module panfile)

[Age]

Hello,

 

For a batch of modules we have done some tests and concluded that although the batch passed the STC acceptance tests. The deviation at low irradiance   (200W/m2) is approximate -4,7 to -5%. (-5% was the limit so the batch just passed) 

However this is lower than according to the panfile used in the pvsyst simulation. We calculated that for our site there is low irradiation during about 2/3rd of operating hours and therefore I would like make a simulation to calculate how big the effect of this deviation is on expected production.

My question is how do I properly adjust the module characteristics to add this effect?

is it sufficient to add the relative efficencies for low light performance or do I model this in a different way?

 

Thanks in advance

 

Age 

 

 

 

 

 

 

[Age]

Hi all,

 

I noticed i can adjust the Rserie value of 0.230ohm in such a way that the graph intersects my given datapoints.

is this the method to adjust accordingly?

Thanks in advance

 

Age

[André Mermoud]

The Rserie adjustment is indeed the main parameter that manages the low-light behaviour.

You can adjust it for getting the desired low-light performance, i.e. matching your experimental points if available.

NB: If you are in the page  "Additional data => Measured low-light data", this is a tool for importing the detailed measurements concerning your module. This tool is an independent help, the parameters you set here are not the parameters of the PAN file.  The PAN file may have different STC values, and when you exit this tool PVsyst will ask if you want to keep the low-light performance of the model established here. If so, as the STC are different the paramerers  RSerie and RShunt suited for the PAN file may be different as in this tool.

[Age]

Thank you André!  I adjusted the  low-light performance of the module and ran the simulation!