Panel Quantity / Arrangement

[Solarwanabe]

Should the number of panels based on charge controller capacity be calculated by VOC and Amp Short Circuit values for a given panel? Do parallel strings have to have the same voltage? What do you do if you can't get the same panels when adding capacity?

 

[kernel]

You can have a pretty heavy mismatch for panels in parallel. Still, to aim for 10% voltage similarity in the nameplates of the modules will avoid poor production mainly in series strings.

At some point you are better off supplying another controller for heavy mismatch caused by shade or orientation. Match similar panels in their own parallel circuits and it will be ok.