Identifying SSC variables in PySAM or the SDK tools

Hi all,

I often get questions about what a particular SSC variable is. For example, someone recently asked about the following variables:


There are a few ways to figure out what these variables are. Keep in mind that this code was originally written for a  desktop application with a user interface, so the variable names and descriptions are not always as clear as they might be.

This example happens to be for the PV model's "Simple Efficiency Module Model", but you can use the same techniques to identify variables for any other performance or financial model.

The first technique is to use the SAM desktop application's user interface. In this case, all variables preceded by “spe” are inputs for the “Simple Efficiency Module Model” option on SAM's Module input page, and you can tell a lot about the variables by looking at how they are presented there:



The spe_a, spe_b, and spe_dT variables are parameters for the model’s cell temperature model:



SAM's inputs browser (File, Inputs browser) displays a searchable table of all input variables in a SAM project showing both the variable's SSC name and, in most cases, the label that appears in the user interface.

The code generator (Case menu, Generate code) generates text files of input variables and values in Python, C, MATLAB, etc. or as JSON match those in SAM as described at sam.nrel.gov/software-development-kit-sdk.html .

If you are using PySAM, you can find variable descriptions in the PySAM documentation . The variables are grouped using a group name based on the SAM user interface. For example, the simple efficiency module model variables belong to the SimpleEfficiencyModuleModel group, and are described at nrel-pysam.readthedocs.io/en/master/modules/Pvsamv1.html?#PySAM.Pvsamv1.Pvsamv1.SimpleEfficiencyModuleModel.

Finally, the SDKtool is a desktop application that comes with SAM and also a good way to explore the SSC compute modules. Find out more about SDKtool at sam.nrel.gov/software-development-kit-sdk.html .

Best regards,
Paul.