IAM Profile

[Rapha123]

Hi,

An increasing number of manufacturers are providing test results for the IAM profile which give significantly improved losses compared to the default settings in PVsyst (at least 1% lower losses). It is possible to input these values into PVsyst, however if the results aren't provided, is it a reasonable assumption to assume a b0 factor of 0.04 for all ARC glass modules?

Cheers,

Raph

[André Mermoud]

There are indeed several "new" performance reports about the IAM.

However this measurement is rather difficult to perform with accuracy, and there are high discrepancies between the results of different laboratories.

I can just propose my own theoretical calculations, according to the Fresnel's laws, for a standard flat glass without Anti Reflective dispositives.

 

IAM Fresnel calculation taking 2 reflexions into account, compared to ASHRAE parametrization.

 

I took 2 reflexions into account, i.e. the first Air-glass interface, the reflexion on the bottom of the glass side (against the PV cells), and the secondary refraction from glass to air.

The next contributions are completely negligible.

[Miled123]

Hi,

I have two sub-arrays with two different IAM profiles for a specific energy run, but the report is only showing the one IAM profile for the first module array I specified not the other. How can we know if PVsyst is accurately ingesting the two different IAM profiles accordingly?