Hydrogen-powered aviation

Project results are expected to contribute to all of the following expected outcomes:

• Innovative ground-based refuelling and supply systems for liquid hydrogen at air transport ground infrastructures, with the potential to be up-scaled at system level by 2027.
• Transformative aircraft-based hydrogen refuelling technologies, with emphasis on safety, standardisation and scalability to various types of aircraft concepts (including Vertical Take Off and Landing aircraft (VTOL) and Unmanned Air Vehicles (UAV)).
• Hydrogen-powered aircraft ground movements, demonstrated and scalable across airports of different sizes, locations and capacities in Europe.
• Comprehensive and validated liquid hydrogen demand and supply-matching models at air transport ground infrastructures in Europe and globally, towards a potential entry into service of hydrogen aircraft by 2035.
• New standards and certification procedures for the roll-out of the new technologies and solutions at large scale, in EU Member States/Associated countries and on the TEN-T network.

Hydrogen-powered commercial aviation is today on a promising path towards climate neutrality by 2050, with European industry setting 2035 as an expected date of entry into service of the first hydrogen-powered commercial aircraft. While the Horizon Europe Clean Hydrogen partnership focuses on the production side (e.g. developing new fuel cells and hydrogen storage technologies), the Clean Aviation partnership addresses the integration and demonstration of disruptive technologies, including ones on hydrogen-powered aviation and subsequent aircraft architectures. However, there is currently a clear research and innovation gap for the phase in-between. Most notably, this gap relates to the demonstration of hydrogen refuelling and supply from air transport ground infrastructures to the aircraft, with follow-on demonstrations of ground-based aircraft movements (e.g. taxiing). In particular, hydrogen refuelling entails significant operational issues, safety risks and other barriers (e.g. scalability) at both air transport ground infrastructure and aircraft levels. This has the potential to create a bottleneck for Europe to proceed on the path to climate neutrality, lower emissions and reducing Europe’s dependency on oil and fossil fuels, which are clear objectives of the Versailles Declaration^[1] and REPowerEU^[2]. At the same time, demonstration pilots of hydrogen-powered aircraft ground movements need to start urgently, in order to be able to achieve full operations of hydrogen-powered airplanes in the EU by 2035.

In this context, building on good practices, studies and research projects (e.g. Horizon 2020 green airport projects, Horizon 2020 ENABLE-H2), as well as other policy initiatives (e.g. Fit for 55 and ReFuelEU Aviation), actions should address all of the following aspects:

• Assessing and validating potential liquid hydrogen demand models at air transport ground infrastructures in Europe and globally, considering also multimodality issues at airports arising from the use of hydrogen in road and rail transport. The techno-economic assessment should also consider the energy supply side and be aligned with the targets, investments and regulatory aspects addressed by REPowerEU, ReFuelEU Aviation, the Alternative Fuels Infrastructure Regulation and the Trans-European Networks for Transport and Energy (TEN-T and TEN-E).
• Testing and demonstrating innovative and safe ground-based refuelling, storage and supply systems for liquid hydrogen at air transport ground infrastructures, going beyond the state-of-the-art and in view of future standardisation, with focus on airports and vertiports serving national, intra-European and/or regional routes. Consideration should also be made to the hydrogen production (including on-site), supply, materials performance, storage and refuelling systems, with the concurrent use other liquid fuels (e.g. kerosene and sustainable aviation fuels) and electricity at air transport ground infrastructures, in order to enable zero-emission airport operations along the entire value chain, from multimodal road/rail connections, to ground handling and aircraft ground movements.
• Developing and demonstrating new aircraft-based hydrogen refuelling technologies, with emphasis on operational feasibility, safety, interoperability, standardisation, scalability and cost optimisation, to showcase a clear technical and business case. The technologies should be compatible with various propulsion technologies and aircraft concepts (e.g. different types of commercial aircraft and architectures, including VTOL and UAV, as also addressed in the Horizon Europe Clean Aviation partnership.
• Performing small-scale demonstration pilots of zero-emission hydrogen-powered aircraft ground movements, in one or two airports (e.g. taxi-in / taxi-out), in view of deploying the new technologies and solutions to various aircraft types and airports across Europe.
• Initiating and developing new standards and certification procedures, for the new technologies and systems to be scalable and serve different types of aircraft and air transport ground infrastructures of various sizes, locations and capacities for both passenger and freight transport.

The EU’s Hydrogen Strategy prioritises renewable hydrogen (low-carbon hydrogen being considered a transitional technology) and should be taken into account to develop the proposals, considering, inter alia, how the hydrogen will be produced and supplied.

The topic aims to exploit synergies with the Horizon Europe Clean Aviation and Clean Hydrogen partnerships, for the roll-out of transformative aircraft liquid hydrogen propulsion technologies, with an eye towards future large-scale demonstrations and real-life airborne plane trials during the later phase of the Clean Aviation partnership. The retained proposals, should, during the implementation phase, regularly exchange information with the Technical Committee and the Governing Board of the Clean Aviation and Clean Hydrogen partnerships respectively (in-line with articles 65 and 80 of the COM(2021) 87).

For standardisation activities and in view of future certification of airports and vertiports and aircraft, including VTOL and UAV, the participation of EASA is deemed necessary to address airport and aircraft certification issues. The involvement of airports, vertiports and aircraft manufacturers in the project activities is required. Since regional and short haul aviation is likely the first segment to start the transition to hydrogen-based fuel technology, the involvement of regional and insular airports in the project will be an asset.

In line with the Union’s strategy for international cooperation in research and innovation, the participation of airports and regulatory bodies outside of the European Union is encouraged.

Projects should collaborate with the Clean Hydrogen Joint Undertaking on aspects that require integration of hydrogen and are expected to contribute and participate to the activities of the TRUST database and the hydrogen observatory.

Activities are expected to achieve at least TRL 6 by the end of the project – see General Annex B.

[1] https://www.consilium.europa.eu/en/press/press-releases/2022/03/11/the-versailles-declaration-10-11-03-2022/

[2] https://ec.europa.eu/commission/presscorner/detail/en/ip_22_1511