Iam For Different Pv-Panels

[SolkraftSweden]

Hi!

 

I was very surprised when comparing two simulations for two different PV-panels. The two is Conergy PowerPlus 260 Watt and JA-solar polychristallin 260 Watt. The production difference were 5%.

I looked in to the database and found the reason. It was the IAM.

For Conergy the parameter was set to 95% and for JA 98%. What is the origin of these kind of parameters? It is taken from an extended datasheet? Or else?

 

The funny thing is that my experience says that the Conergy panel is producing more compared to the JA panel in lower irridance.

 

Some who knows?

 

BR Per Halldin, Solkraft i Viby AB

[hotline_sf]

Dear Per Haldin,

 

The entries in the database are made by the manufacturers themselve. We just check if the entries generally make sense and release it in a database update. So, the IAM is entered by the manufacturer. They know which glass, coating etc. they are using.

 

Another problem is the part load characteristic of the modules. The manufacturer have the option to enter a specific characteristic for the entered module. If they don't do taht then a standard part load characteristic of the selected module type, e.g. polycrystalline, is assumed. This is a mean part load characteristic which guarantee that the simulation results are not above the real yield.

 

In your case Conergy as selected a standard part load characteristic and JA Solar as entered a specific one. That's why you have probably better results with the Ja Solar module.

 

Best regards

 

Your Technical Support

[SolkraftSweden]

Thanks for the answer!

 

Do you any "sanity checks" of these kind of parameters?

 

Without telling any brand, I have compared different panels in real and compared the results to what PV*SOL calculates. I suspect that IAM-values over 96/97% is not possible.

What is your opion about my results?

 

BR Per Halldin, Solkraft i Viby AB

 

 

 

[hotline_sf]

Dear Per Haldin,

 

we check the basic characteristics of the entries, like MPP voltage, MPP current etc. But it's just a genaral automatic check if they make sense. We have thousends of products in the database. So we cannoot compare every entry manually with the datasheets.

 

We don't check the IAM. It's usually not on a datasheet and we also don't know which glass and coating is used on the modules.

 

We also don't know if an IAM higher than 97% is not possible. It's generally hard to find information or scientific papers about this issue.

 

Best regards

 

Your Technical Support

[SolkraftSweden]

Dear Per Haldin,

 

we check the basic characteristics of the entries, like MPP voltage, MPP current etc. But it's just a genaral automatic check if they make sense. We have thousends of products in the database. So we cannoot compare every entry manually with the datasheets.

 

We don't check the IAM. It's usually not on a datasheet and we also don't know which glass and coating is used on the modules.

 

We also don't know if an IAM higher than 97% is not possible. It's generally hard to find information or scientific papers about this issue.

 

Best regards

 

Your Technical Support

Thank you for the answer!