Hydrogen is one of the great hopes for sustainable aviation, alongside synthetic kerosene jet fuel–assuming either can be made en masse cleanly. And Airbus has been especially bullish on the lightest element–promising that it will propel smaller commercial aircraft by 2035 and even jumbo jets after 2050.
But the aviation giant is already progressing on a more modest goal of using hydrogen fuel cells to power auxiliary features such as air conditioning and other onboard electronics on its airliers. This could take the place of the kerosene-powered turbines that currently do the job.
Today Airbus and a company called H3 Dynamics announced plans to deploy the latter’s 500-kilowatt hydrogen fuel cell auxiliary power unit (APU) in trials next year. It will go into Airbus’s UpNext test craft, a 400-seater A330 airliner modified to test new technologies. The news follows a year after Airbus said that the companies would work together.
Powering Whole Planes with Hydrogen
Further out, Airbus is testing technology to power smaller airliners entirely on fuel cells, but that requires a lot more energy. In 2020, the company announced development of 100-seat aircraft running on fuel cells and capable of flying up to 1,000 nautical miles. Airbus is testing 1.2 MW fuel cells to power the plane—and it will require six of them.
Driving smaller planes with fuel cells, like the coming crop of air taxis that seat about six people, would be an easier goal to meet. Those in development from companies like Archer and Joby require around 1.5 MW or less in total. That said, these companies are all focussing on improving their lithium-ion battery packs, rather than jumping to hydrogen.
In parallel, Airbus is also testing conventional jet engines reengineered to burn hydrogen in place of jet fuel. But this presents its own problems. Even supercooled and compressed, hydrogen takes up considerably more space per unit of energy than kerosene.
The Green Hydrogen Challenge
It’s a long way from a single demonstration to remaking airliner fleets. But there’s not exactly a need to rush, as inexpensive green hydrogen is still a ways off. Hydrogen has been used in the petroleum and chemical industries for ages. (It goes into making fertilizers, for instance.) But virtually all of this is “gray” hydrogen, derived from fossil fuels—typically natural gas—and producing greenhouse emissions in the process.
Green hydrogen, which uses electricity to split water molecules, costs about five times as much to refine, according to BloombergNEF. And it takes a lot of energy, which would have to come from wind, solar, or other green sources. Efforts are underway to reduce costs. In the U.S., the Biden Administration aims to get the price to $1 per kilogram (about what gray hydrogen costs) by 2031. If it works, that ambitious green production timescale could line up well with Airbus’s ambitious green deployment timeframe.
