One of the latest ideas for Airbus’ research and development quest for zero-emission flight is a hydrogen-powered pod propulsion system. The new concept includes six removable fuel cells designed to be disassembled and reassembled for quick swaps at airports.
In September, Airbus revealed three ZEROe concept aircraft, all relying on hydrogen as a primary fuel source. Two of the aircraft were fairly classical; one narrowbody turbofan for 120 to 200 passengers and one turboprop for the 100-seat regional market.
The third, seating up to 200 passengers, was a breakout concept with a wide fuselage and blended wing. The planemaker then gave itself five years to deliver a commercially viable hydrogen-powered aircraft.
Individual systems with liquid hydrogen
The newest idea falls somewhere in between, with a classical fuselage shape but innovative engines. It consists of six “pods” with eight blades each, mounted under the aircraft wings. While the design itself may not be groundbreaking, the fact that the pods would be powered by hydrogen cells is.
“The ‘pod’ configuration is essentially a distributed fuel cell propulsion system that delivers thrust to the aircraft via six propulsors arranged along the wing. Hydrogen fuel cells have very different design considerations, so we knew we had to come up with a unique approach,” Matthieu Thomas, ZEROe Aircraft Lead Architect, said in a statement seen by Simple Flying.
Each pod is essentially a stand-alone propulsion system that would consist of:
- a propeller
- electric motors
- fuel cells
- power electronics
- LH2 (liquid hydrogen) tank
- a cooling system
- a set of auxiliary equipment
Potential solution to refueling problems
One of the key features of the potential system is that it is designed for quick swaps. This could provide a solution to the problem with refueling at airports, which experts have raised as one of the main issues facing hydrogen-powered flight. Thanks to its removable features, it can be dismantled and reassembled in record time.
“This ‘pod’ configuration is a great starting point to nurture further inquiry into how we can scale up hydrogen technology to commercial aircraft. This is one option, but many more will be conceptualised before we make a final selection, a decision that is expected by 2025,” says Glenn Llewellyn, VP of Zero-Emission Aircraft.
Is hydrogen really zero-emission?
Hydrogen is proclaimed by many as one of aviation’s best bets at reducing carbon emissions. While hydrogen itself does not produce any carbon dioxide when used as a fuel source, at the moment, hydrogen used as fuel is produced from fossil fuels; a process that in and of itself releases carbon dioxide and monoxide into the atmosphere.
Hydrogen retrieved in this manner is usually called “brown” or “grey” hydrogen. Its slightly more environmentally friendly option, where emissions are reduced using carbon capture and storage, is known as “blue” hydrogen.
So while a hydrogen-powered plane, such as the retrofitted Piper Malibu operating ZeroAvia’s first commercial-grade hydrogen flight in September, could be called “zero-emission,” at the moment, the fuel supply chain could not.
However, this could also become a reality with the production of “green hydrogen.” This is done through electrolysis, using renewable energy sources such as solar, hydro, or wind power. Meanwhile, at the moment, green hydrogen unfortunately only accounts for 1% of total annual hydrogen production.
What do you think of Airbus’ hydrogen-powered pod concept? Let us know in the comments.