A fuel cell system comprises a fuel cell module, at least a cathode gas supply unit in contact with the cathode, at least one gas delivery unit and at least one anode fuel supply unit in contact with the anode. The fuel cell module comprises at least one fuel cell having one anode and one cathode. The cathode gas supply unit comprises at least one gas input port for receiving cathode gas and at least one gas exit for exhausting the cathode gas. The gas delivery unit guides the cathode gas to the gas input port. The anode fuel supply unit having a fuel comprises at least one fuel input port for receiving a resupplied fuel and at least one cathode gas input port for receiving the cathode gas from the gas exit.