Running SAM .lk script from Python

Hi Joel,

The general definition is:

DC - AC Ratio = Array DC Nameplate Capacity (kWdc) / Inverter AC Nameplate Capacity (kWac)

To calculate the ratio, assuming you are using the Sandia Inverter model and CEC Module Model with Database Paramters model, you could write Python code based on this pseudocode:

pdc = get( cec_imp_ref ) * get( cec_v_mp_ref)
pac = get( inv_snl_paco )
dc_ac_ratio = pdc / pac

Where get() is whatever function you are using to read the values of SSC input variables. Those values should all be in kW,.

Thanks,
Paul.

Hi Paul,

Thank you so much! This is very helpful to what I am doing. Just wondering, how would the pseudocode formulas you have written change if I am using CEC for both the inverter and the module? Specifically, I am using "CEC Performance Model with Module Database" and "Inverter CEC Database".

Thanks,
Joel

Hi Joel,

The "Inverter CEC Database" model is the same as the Sandia Inverter model, whose input variable names mostly start with "inv_snl_". Sorry these model names are so confusing.

Thanks,
Paul.

Hi Paul,

Thanks for your help - I have managed to solve the issue!
A follow up question: How would I be able to tell if my simulation is using the '6par_' module parameters as opposed to the 'cec_' module parameters? Does it always default to cec? or is there a way to change the simulation between using 6par and cec for the modules?

Kind regards,
Joel

Hi Joel,

Use 'module_model' to set the model option. There is a description here:

nrel-pysam.readthedocs.io/en/master/modules/Pvsamv1.html#module-group

Best regards,
Paul.