Open-circuit voltage

Also known as Voc

Open-circuit voltage is the voltage at a solar PV module, string or array when it is illuminated but not delivering current to a load or inverter.

Open-circuit voltage, often written as Voc, is the voltage present at a solar PV module, string or array when the circuit is open and no current is flowing. Module datasheets list Voc under standard test conditions, and a string's open-circuit voltage is checked against inverter and other DC-side voltage limits because cold panels can have a higher open-circuit voltage than their warm operating voltage. Open-circuit voltage is not the same as maximum power point voltage, operating voltage, kWp, module efficiency, export capacity, DNO acceptance, installation compliance or evidence that a circuit is safe to work on.