De är skyldiga. Om panelen blir skuggig betraktas den som DARK. Om panelen är smutsig är den mörk. Vad händer är din producerade spänning har en PATH till den andra panelen. Dioden blockerar den åtgärden - tillåter ström att strömma i endast en riktning.
These blocking diodes, also called a series diode or isolation diode, ensure that the electrical current only flows in one direction “OUT” of the series array to the external load, controller or batteries.
The reason for this is to prevent the current generated by the other parallel connected PV panels in the same array flowing back through a weaker (shaded) network and also to prevent the fully charged batteries from discharging or draining back through the array at night. So when multiple solar panels are connected in parallel, blocking diodes should be used in each parallel connected branch.