BMW of North America and NASA have completed an eight-week test period of the BMW Hydrogen 7. During the test period, the vehicles, which feature a type of combustion engine capable of running on either liquid hydrogen or gasoline, were refueled using the NASA space center’s liquid hydrogen fueling supply.
According to sources at BMW, because the vehicle uses liquid fuel, a domestic hydrogen generator based on electrolysis would not be practical. Rather, the vehicle is designed for use with a centralized liquid-hydrogen infrastructure, and the dual operating mode of the vehicle allows it to use gasoline when liquid hydrogen is unavailable.
BMW states pressure in the fuel tank drives hydrogen gas to the internal combustion engine, where it is mixed and burned. The engine uses a 12-V electrical system and electronic ignition to drive the spark plugs for both gasoline and hydrogen fuel. These spark plugs are the same variety used in racing cars to provide a high-precision spark.
Technical Editor’s note: The BMW’s Hydrogen 7 uses liquid hydrogen to power a mechanical drive train, and BMW does not plan to develop a liquid-hydrogen fuel cell vehicle with an electric drive train. However, the high power density of liquid hydrogen does make it an attractive fuel for powering the electric drives of unmanned aerial vehicles, such as the platform discussed here.