Hydrogen-Powered Aircraft: Hydrogen–electric hybrid propulsion for aviation

The ever-increasing demand for passenger air travel means unprecedented aircraft market growth in the coming decades. However, large airline fleets lead to serious environmental concerns. A clear goal was set during the 2021 United Nations Climate Change Conference (COP26): securing global net-zero emissions by midcentury while keeping 1.5 °C of temperature rise within reach. Hydrogen (H
₂
) propulsion technology provides one of the most promising opportunities to meet this target and decarbonize global aviation. Thus, this article reviews and collates state-of-the-art research related to H
₂
–electric hybrid aircraft. After introducing the potential benefits of H
₂
propulsion, fuel cell (FC) auxiliary power in airplanes and H
₂
FC-powered aircraft are discussed. Finally, challenges/recommendations for future research as well as an outlook on H
₂
-powered aircraft are presented.