The H2Sky project, launched in 2022, has now been completed. As part of the National Innovation Programme for Hydrogen and Fuel Cell Technology (NIP), it received around €26.5 million in funding from the Federal Ministry for Digital and Transport. According to the ministry, H2Sky is one of the largest projects in Germany focused on developing hydrogen-based fuel cell technologies for aviation.
The project’s core focus was the development of aviation-optimised fuel cell stacks with a power output of 100 to 200 kW, designed to power an electric motor driving a propeller or engine. It addressed the particularly high demands of aviation in terms of power density, efficiency, reliability, and lifespan. However, specific data on the newly developed fuel cell stack remains unavailable.
“Climate-friendly mobility will succeed where innovation and competitiveness go hand in hand. In aviation, hydrogen plays a key role,” said Germany’s Minister for Digital and Transport Patrick Schnieder (CDU) at a closing event. “Projects like H2Sky demonstrate that German ingenuity and technology are driving progress towards low-emission air travel.”
Andreas Hubert, CEO of Aerostack, added: “In the H2Sky project, we successfully advanced fuel cell technology to meet aviation requirements and significantly increased its technological maturity. The results provide a robust foundation for the next steps in preparing the technology for market readiness.”
However, an aviation-ready fuel cell stack is just one of many pieces of the puzzle required to enable hydrogen-powered flight in the future. A complete powertrain is needed, which includes not only the fuel cell stack but also cryogenic tanks (for liquid hydrogen at -253 °C), thermal management systems, and power electronics. Additionally, years of testing and certification by authorities will be required.
This may explain why the Federal Ministry for Digital and Transport avoided the term “aircraft” in its press release, as a commercial fuel cell-powered aircraft is still years away. Airbus, which is involved via its stake in Aerostack, had initially targeted 2035 for hydrogen-powered aircraft under the ZeroE programme, but has since deprioritised the effort, making 2040 a more realistic timeline.
At the same time, Airbus and Aerostack, together with the PEM Chair of RWTH Aachen University and the German Aerospace Centre, have launched the new ‘GENtwoPRO’ project. The initiative aims to develop a scalable fuel cell system for regional aircraft with up to 100 seats.
The now-concluded H2Sky project was coordinated by the national organisation NOW and implemented by Project Management Jülich (PtJ). The consortium was led by Aerostack. Other partners included EKPO Fuel Cell Technologies, Hahn-Schickard, the Fraunhofer Institute for Solar Energy Systems ISE, the Technical University of Munich, the Centre for Solar Energy and Hydrogen Research Baden-Württemberg, and the University of Freiburg.
bmv.de (in German)