CEC Performance Model with User Entered Specifications

Hi Paul,

I'm having a hard time trying to model some First Solar Series 6 CdTe modules that are not in the database and using the CEC Performance Model with User Entered Specifications. These are larger modules designed specifically for utility scale projects, so the voltages and currents are higher than typical CdTe modules. I noticed if I bring down the voltage to 150 V, it will model the module and produce and IV curve, but any voltage above 150 V produces an error, adjusting the current doesn't seem to help any. Also if I choose another cell type such as Mono-Si, then the model works. I'm wondering if there are limitation on the CdTe cell and how I can get this module into the system.

I provided a clip of the SAM specifications that I'm entering and the Series 6 Data Sheet that I'm using.

Any help would be greatly appreciated.

Thanks,

Bill W

Dear Bill,

Thank you for the clear statement of your question, and for providing supporting documents.

For some types of modules, the algorithm SAM uses to calculate the six parameters of the CEC module model fails to find a solution. This is particularly true for thin film modules because of the a parameter, or "modified nonideality factor", as described in Dobos 2012 (see the Detailed Photovoltaic Model references at sam.nrel.gov/performance ).

We'll look into this further and I will follow up when we learn more.

Best regards,
Paul.

Hi Paul,

Thanks for getting back to me, and looking into this. I'll take a look a the link, so I can better understand the modeling parameters and limitations. Let me know what you find.

Best,

Bill W

I am facing similar problem while entering the parameters for the FS-6440 First Solar S6 Series 440W (utility-scale) into the CEC Performance Model with user entered specifications, since data for such module is not available at the SAM library. The simulation cannot proceed. Please, has this issue been resolved? If not, is there another way to enter data and model these PV panels?

Thank you,

Allan Montanari

Hi Bill and Allan,

We're still looking into this. Thanks for the reminder. We don't have a workaround solution at the moment.

You can track progress on this issue on GitHub at:

github.com/NREL/ssc/issues/129

Best regards,
Paul.

Thanks for bringing this to our attention. This bug has been fixed (details can be found on the Issue page) and will be included in the next version: github.com/NREL/ssc/issues/129 .