The 10 kW fuel cell subsystem is the latest result of continuous system optimization. Based on the BZ 560 fuel cell stack design. The main focus of this system is to achieve a high overall efficiency by eliminating parasitic losses and reduced system dimensions. Possible fuel options are pure hydrogen or reformate gas. The nominal electrical output is 5 to 10 kWel, depending on application needs. Compact system architecture with clearly arranged external interfaces allows an easy integration of the system into different customer applications. Possible applications are off grid power supplies, power supplies for mobile hybrid power generators or as a cogeneration system to supply heat and electricity.