For the Detailed Photovoltaic model, before you run a parametric analysis on
Desired DC-AC Ratio (desired_dc_ac_ratio) or
Desired Array Size (desired_size), be sure to check
Estimate Subarray 1 configuration on the System Design page. Otherwise when you run a parametric simulation, it will appear that changing the DC-AC ratio or system size has no effect on results.
For example, here are results for a parametric simulation on system size
without checking the estimate Subarray 1 configuration option, where you can see that the annual energy and net present value do not vary with the desired sytem size:
By adding the System Nameplate DC Rating (nameplate_dc_rating) output to the list, you can see that SAM did not vary the actual size of the system:
Now, if we rerun the parametric simulation after checking
Estimate Subarray 1 configuration on the System Design page, we get the results we expected:
If you are modeling a system with more than one subarray and want to do a parametric analysis on system size or DC-AC ratio, then you will have to adjust the numbers of modules in each subarray, and possibly the number of inverters:
Subarray 1 modules per string (subarray1_modules_per_string)
Subarray 2 modules per string (subarray2_modules_per_string)
Subarray 3 modules per string (subarray3_modules_per_string)
Subarray 4 modules per string (subarray4_modules_per_string)
Number of parallel strings 1 (subarray1_nstrings)
Number of parallel strings 2 (subarray2_nstrings)
Number of parallel strings 3 (subarray3_nstrings)
Number of parallel strings 4 (subarray4_nstrings)
Number of Inverters (inverter_count)
Best regards,
Paul.