Method for measurement of DNI

Dear SAM team,

I'm evaluating the solar cell using DNI.

I'd like to ask you the following questions;

How does DNI of SAM measure it?

Measurement direct pyrheliometers?

or estimation from the GHI?

Thanks and Regards.

Hello,

The source of the solar radiation data in the weather files in SAM's solar resource library depends on where the file came from. To find out how the values of direct normal irradiance (DNI) were determined for a particular file, please see the data source documentation. You can find a list of data sources for the solar resource library in SAM's help system, in the topic for the Location and Resource page: In SAM, go to the Location and Resource input page, and press the F1 key (command ? in OS X) or click the Help button at the top right corner of the SAM window.

Best regards,
Paul.