Irradiance mismatch between PVsam1 and pv6parmod

  • jtopham
  • Topic Author
More
02 Oct 2013 15:18 #1852 by jtopham
Paul,

I had sent you an e-mail about this issue in the past and I wanted to follow up because it could be causing other users some problems with their results.

This is relating to 'pv6parmod' inputs from 'pvsam1' outputs. I wasn't able to obtain all of the neccessary inputs for the 'irradproc' function so I resorted to using pvsam1 for exclusively this data. I am looking for the hourly current and voltage of a module, and the only function which supports this natively is the pv6parmod function.


the input parameters come from
// from SSCdev pvsam1
SSC_OUTPUT SSC_ARRAY hourly_glob_horiz_rad Global horizontal irradiance kW/m2
SSC_OUTPUT SSC_ARRAY hourly_beam Beam irradiance kW/m2
SSC_OUTPUT SSC_ARRAY hourly_diff Diffuse irradiance kW/m2

output parameters are:
// From SSCdev pv6parmod
SSC_ARRAY poa_beam Incident direct normal radiation W/m2
SSC_ARRAY poa_skydiff Incident sky diffuse radiation W/m2
SSC_ARRAY poa_gnddiff Incident ground diffuse irradiance W/m2


Now, counter-intuitively I must multiply the input parameters by 500 to get approximately the nominal current and voltages expected under real conditions. If I divide by 1000 like the units express I get zero, and if I multiply by 1000 I get current and voltages far exceeding the Isc of the module.

I presume pv6parmod function is relatively unused by most users and probably isn't worth fixing because most of the parameter names do not match up well either. I would really appreciate if either hourly voltage, temperature, and current values would be added to pvsam1, as they are essential for optimizing the conductors as well as other parts of the design which is what I have been working on.

----
problem 2:

The pvsam1 is no longer recognizing 'use_wf_albedo' with an input of 1. I have not changed my weather file and I believe my weather file has an albedo. It has not changed in SSCdev and I was wondering it perhaps SSCdev has not been properly updated to reflect any possible changes.

Thanks,

Jon

Please Log in or Create an account to join the conversation.

Moderators: Paul Gilman
Powered by Kunena Forum