analysis of solar power plant

There are several factors that might cause SAM's results to be different from measured data from a real system. For example, the weather data you use for SAM's simulation should represent the same conditions under which the real system operated. Also, you should make sure that the shading and loss assumptions in SAM are consistent with how the real system operates. And, you should be careful that the module, inverter, and system design parameters in SAM are the same as those for the real system.

You might find these photovoltaic system case study reports to be helpful:

sam.nrel.gov/case-studies

Best regards,
Paul.

When you change the module parameters to compare different cell types, you should be sure to take into account the nominal capacities of the different modules. There are factors of a module's design other than the cell type that affect its efficiency. For example the module cover might affect the module efficiency.

SAM reports the energy yield metric and module efficiencies in each simulation time step that might be useful for this kind of comparison.

Best regards,
Paul.