DC Wiring Losses

DC wiring losses are mainly caused by the ohmic resistance of the cabling that interconnects PV devices and strings, although losses can also occur in connections and fuses. The $$I^2\times R$$ power loss varies as a function of the array current squared. Differences in cable length or size among parallel strings can introduce differences in voltage drop, $$I\times R$$, and therefore contribute to mismatch. Series protection diodes are another source of voltage drop.