IAM, Anti-reflective Coating, First Solar FS-4120A-3 versus FS-4120-3,

Hi Paul,

I modeling a project using First Solar FS-4120A-3 panel which includes a antireflective coating. I would expect to see less module losses than when using the FS-4120-3 which doesn't include the coating, but both results are exactly the same. I read that the Incident Angle Modifier, (IAM) is taken into account in the CEC Performance Model, and shows up in SAM in the results in the Module Losses. I would think that the antireflection coating would have less losses than the same panel without the coating. I uploaded the SAM model so you can see what I'm talking about.

1. Is there a better way that I can account for this that shows up in the results?

2. Can adjust the IAM to account for the antireflective coating in the CEC Performance Model with Module Database?

Thanks,

Bill W

Dear Bill,

The parameters in the CEC module library for those two modules are identical, which is why you get the same results for the modules.

The CEC module model uses the 4th degree polynomial of absolute air mass, or air mass modifier, from the Sandia PV Array Performance model (Sandia module model) and described as f2 here on the Sandia PV Performance Modeling Collaborative website. The CEC module model in SAM uses a coefficients for polycrystalline cells from the Sandia module model.

For more detail on this topic, please see this post:

sam.nrel.gov/node/70830

Best regards,
Paul.