What is Panel mismatch?
Even two photovoltaic modules manufactured on the same day on the same production line can have slight variation in performance due to inaccuracy of production processes. Most modern PV panels are grouped into strings and are connected to a single inverter. This results in the weakest panel affecting the performance of other panels in a string. It is estimated, that such a panel mismatch reduces the power output of the whole PV system by approximately 2 percent. The output reduction can be minimized if a solar installer tests each panel performance individually.