The maximum voltage measured when no load is connected. 2V for standard residential panels. . This is your typical voltage we put on solar panels; ranging from 12V, 20V, 24V, and 32V solar panels. Example: A nominal 12V voltage solar panel has an. . Solar panel output voltage typically ranges from 5-40 volts for individual panels, with system voltages reaching up to 1500V for large-scale installations.