Hi Francisco and Johannes,
If you want to optimize the solar field from PySAM, you will need to run the SolarPILOT module.
These models are complicated, and we do not have documentation of how to manage the inputs and run these compute modules in the way SAM's user interface does.
SolarPILOT is available as a standalone model with more features than the version built in to SAM here:
www.nrel.gov/csp/solarpilot.html
Best regards,
Paul.