At the Stuttgart airport, the German Aerospace Center (DLR) presented the first manned airplane that can take-off and fly exclusively with a fuel cell. The innovative fuel cell, based on a high temperature polymer electrolyte membrane (PEM), generates power for the electric engine of the motor glider Antares DLR-H2. The aim of the project is to evaluate the potential of the technology for future applications in commercial aircraft.
In airplanes on ground, turbines or ancillary aggregates generate the energy for air conditioning. During flight, a part of the energy generated in the main turbines is used for a variety of electrical applications as well as for air conditioning. In the future, fuel cells could be an environmentally sound and energy efficient alternative for an aircraft’s electrical requirements. As an auxiliary power supply, a fuel cell would generate electrical power, heat and even potable water for on-board usage. Thus, fuel cells would help reduce weight and electrical power failure risk as several distributed fuel cells replace the turbine generators. For the foreseeable future fuel cells are not expected to be used for large commercial aircraft propulsion.
Before being adapted for aircraft, however, the technology needs further development and testing. The DLR is a leading partner for the aircraft industry for this effort. First results from the DLR testing demonstrate excellent performance of the high temperature PEM fuel cells even under difficult low pressure conditions. This technology is based on Celtec®-membrane electrode assemblies (MEA) by BASF, a technology easily integrated into aircraft auxiliary power fuel cells.
Three partners are cooperating in the evaluation of the high temperature PEM fuel cell: BASF, as manufacturer of the only commercial membrane electrode assembly for this fuel cell type; the Danish company Serenergy A/S, supplier of the compact, air-cooled stack; and, DLR, responsible for the integration of the stack in the fuel cell system and subsequently in the airplane. DLR will also conduct the testing according to the special requirements of aviation.
High temperature PEM fuel cells operate at 120 to 180°C, need no humidification, require only a simple cooling system, offer a broad operating window and tolerate impurities in the hydrogen fuel gas. The latter characteristic is especially important if, in the future, impure hydrogen is sourced from jet fuel reformation on board the aircraft.