According to different online news sources, Liebherr Aerospace & Transportation and US automaker General Motors (GM) have agreed to co-oridnate their efforts and expertice in fuel cells to develop a next-generation auxiliary power unit (APU).
An auxiilary power unit or APU is a small engine that proveds the aircraft with electricl power, air conditioning, power for the lights and compressed aire while the aircraft is on the ground and can also provide backup power in flight if required.
All of today's APU's are fossil fuel driven. A fuel cell APU would emit zero emmissions, zero nitogen oxide, zero exhuast fumes and zero noise. Unlike the APUs used today, fuel cells, as energy suppliers for ground-based aircraft, do not emit any emissions.
According to the news sources and as part of their collaboration, the two companies first want to build a system demonstrator that will also fly in an airplane. It has not yet been decided in which type of aircraft or class of aircraft the demonstrator should be used. It is also not decided where the project headquarters will be located until the choice of the demonstrator airplane is stopped.