Open-circuit voltage (Voc)
The voltage across an unloaded (open) photovoltaic device at a particular temperature and irradiance.
Note: For unregulated systems, the open-circuit voltage may be greatly in excess of the nominal voltage.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM