Gross Power

The primary power output of a fuel cell stack prior to any conditioning and parasitic losses associated with the production of power suitable for the connected load. Parasitic losses include the electrical requirements of the balance of plant and losses inherent in the power electronics that convert (see Converter, Inverter) unregulated DC from the fuel cell stack to regulated DC or AC.

Source : Fuel cell glossary. http://www.sanewsletters.com/FCIR/glossary1.asp