March 12, 2021, ©. Leeham News: I had the chance to talk about Sustainable Air Transport with Airbus VP Zero Emission Aircraft, Glenn Llewellyn, in the week.
The discussion centered around Airbus’ overall direction and the targets with their ZEROe project.
Llewellyn started by stressing that Airbus’s ideas around hydrogen airliners are not new. Already in 2016, hydrogen was a clear alternative when Airbus looked at sustainable aviation.
As the Electric and Hybrid-Electric alternatives became less attractive, the hydrogen-fueled track strengthened. The French state’s investment in hydrogen aeronautics announced in June 2020 supported Airbus’ direction, but it did not change it.
Another point Llewellyn stressed was Airbus’ equal support for Sustainable Aviation Fuel, SAF. “SAF is very important for us as a complement to hydrogen. It’s the only alternative for the existing fleet and a future long-range aircraft. Our SAF support has drowned in the interest in our hydrogen work. But hydrogen is one part of the solution, SAF is the other. Hydrogen is the solution for regional and intra-continental traffic as it has better operating economics. For long-range aircraft, the volume demands of hydrogen make SAF the only carbon-free alternative.”
The third point for Llewellyn was the importance of a broad hydrogen eco-system. Air transport is only a smaller part of a hydrogen economy. Airbus, therefore, actively engages with ground transport (trucks, busses, cars, trains), energy and space industries to create a rational and effective production and distribution system for hydrogen. Regarding distribution, he mentioned the low weight of hydrogen makes tankering possible, which means not all airports in a future network need LH2 installations.
“Right now, for the next years, we are developing and testing technologies and engaging in infrastructure discussions. It’s still too early to talk about demonstration aircraft, and decisions around an aircraft for introduction 2035 can only be made after we have evaluated the result of the present work packages,” said Llewellyn.
He gave examples of how the ground transport industry has developed the fuel cell, focusing on a low cost of manufacture. For airliner applications, the balance skews towards performance, which is the focus for Aerostack Gmbh, its joint venture with ElrinKlinger AG around advanced fuel cells.
We then discussed the results of my calculations around propulsion and auxiliary power to the aircraft. Llewellyn stressed Airbus’s goal is zero emissions, thus the name ZEROe for the presented concepts.
The fuel cell has the advantage here (no NOx and Soot emissions, H2O is not emitted as ice crystals). Depending on the performance it can achieve, it will set the balance between fuel cell and gas turbine propulsion for future hydrogen aircraft. For auxiliary power, the fuel cell has many advantages.