What are the negative effects of wiring two dissimilar solar modules together in series?

I have a few extra solar panels from another project that are the same STC name plate rating as the modules for my current job but are from a different manufacturer.  What will happen if I string together dissimilar modules in series in solar installation?  Will there be losses?


When modules of an array are wired together in series, the voltage is additive and the current remains constant.   When the modules are wired together in parallel, the current is additive and the voltage remains constant.    If two similar modules are wired together in series, the current remains the same and the voltage will double.  However, when two dissimilar modules are wired in series, the voltage is still additive, but the current will be only slightly greater than the current produced by the panel with the lowest current output in the series string.  

In other words,  there is a large difference in the output of the modules so it may be better not to use those panels or to wire them in a separate array rather than to combined them.  

9 years 11 months ago
Asked by
Jeff Ramsay
Support topics
Solar panel
Wiring and circuits