Hello dear developers,

I was recently comparing two simulations using different modules but with identical weather conditions and mounting surfaces and I was surprised by the difference in losses due to the reflection on the module's surface:

 

I am a bit worried about this difference, as both modules are from the same manufacturer and both have anti-reflective coating. In the upper case, I had to create the module (JKM525M-7TL4-V), as it was not in the database, and I don't recall having been asked anything by PV*SOL in this regard, so I don't know if I may have made a mistake...

 

I am attaching the datasheet of the module I used which apparently loses 5,98% of its power due to reflection. Any help with this issue and of where I may have gone wrong would be much appreciated, so thanks in advance!

 

 

TR JKM520-540M-7TL4-V-A1-EN.pdf

Hey Ricardo,

These are two different modules and there is no reason for me to believe that both the modules have similar anti-reflection coating and cell-surface polishing for Total Internal Reflection (TIR).

I also see some difference in Module inclination and orientation losses. Of course it is marginal but this still could show some impact on reflection losses.

-Vishnu

Hi Ricardo,

these reflection losses are mainly influenced by the IAM value (incidence angle modifier) that is part of the module data. Using this value we calculate the reflection as decribed here:

https://help.valentin-software.com/pvsol/2020/calculation/pv-modules/reflection-in-module-plane/

Also, see these threads on the same topic:

 

So, in order to compare your two results and explain the differences, we would need the two projects with the two modules. If one of those modules was created by yourself, check the IAM value of that module, if it is the same as the other module.

Kind regards,

Martin

Hi,

Thanks for the quick replies and for pointing me to those threads. It seems I may indeed have made a mistake creating the module, but I don't know where. I didn't see the IAM value on the datasheet and I didn't see any way to enter it when I created the module, could you please show me how to do that and what value I should include? If having my project would help, please let me know how to send it to you privately, Martin, as it has some confidential information and I don't want to share it publicly ?

Thanks and regards,

Ricardo

Hi Ricardo,

you can find the IAM under "Additional parameters":

Kind regards,

Martin

Thanks Martin, I had missed that.

Kind regards,

Ricardo