Abstract: A fuel cell system includes a fuel cell stack that includes PEM fuel cells. Each fuel cell has an operating temperature of at least 120° C. The fuel cell stack has a cathode inlet to receive a flow of ambient air and a cathode outlet to provide a cathode exhaust flow. The fuel cell system includes a fuel processing reactor that has an inlet and an outlet. The inlet and outlet are in fluid communication with a catalyst that is suitable for converting a hydrocarbon into a gas that contains hydrogen and carbon monoxide. The outlet is in fluid communication with an anode chamber of the fuel cell, and the outlet of the fuel processing reactor is in fluid communication with the cathode outlet.

Abstract: A technique that is usable with a fuel cell stack includes providing a reactant flow to the fuel cell stack. The output current of the fuel cell stack is regulated to cause an output power from the fuel cell stack to be near a peak output power for the reactant flow being provided to the stack, and the reactant flow to the stack is controlled to regulate the output power from the fuel cell stack near a desired power level.