A single solar cell has a voltage of about 0. Voc (open-circuit voltage) is the highest — typically 38–55 V for residential panels — and is what the inverter sees when no current is flowing. 6 inches thick, weighs 40–55 lb, and produces 350–460 watts. The full size-by-wattage. There are three main things to look at when checking out solar panel specifications: Voltage: Voltage is like the water pressure in a hose. ” Solar panels differ in voltage: Current: This is like the amount of. What Voltage Are Solar Panels? Voc, Vmp & Design Guide What Voltage Are Solar Panels? Voc, Vmp and Design Guide Residential solar panels produce 34-45 V depending on load. In simpler terms, it's the force that pushes electric charge through a conductor.