Components Development and Experimental Testing for an Onboard Liquid Hydrogen Supply and Conditioning System in High-Power Fuel Cell Aviation Applica...

The HORIZON-JU-CLEANH2-2026-03-02 call, titled "Components Development and Experimental Testing for an Onboard Liquid Hydrogen Supply and Conditioning System in High-Power Fuel Cell Aviation Applications," is part of the Horizon Europe program overseen by the Clean Hydrogen Joint Undertaking. This initiative aims to advance the development and validation of essential components for liquid hydrogen supply and conditioning systems specifically designed for electric propulsion in fuel cell aircraft. The project addresses critical technology gaps in hydrogen utilization for sustainable aviation.

Eligible applicants include research organizations, universities, industrial partners including both small and medium-sized enterprises, and public entities. Consortia must consist of at least three independent legal entities from different EU Member States or Associated Countries, with at least one member from an EU country. Collaboration among diverse stakeholders, such as aircraft manufacturers and certification bodies, is encouraged. The funding structure offers lump sum grants, with a maximum EU contribution of EUR 8 million per project.

Projects are expected to progress to Technology Readiness Levels 4 and 5, focusing on designing, developing, and validating components such as cryogenic valves, insulation, and metering systems necessary for liquid hydrogen systems. Additionally, the call emphasizes the importance of simulation and experimental analysis to ensure reliable operation under varied conditions. Specific operational and performance indices are targeted, including achieving a peak hydrogen mass flow for aircraft and maintaining high performance with regards to safety and efficiency.

The opportunity is structured as a single-stage open call, with a submission period running from February 10 to April 15, 2026. While co-funding is encouraged, it is not mandated. Success rates for proposals are not explicitly published, but they are predicted to be competitive based on historical data, with evaluation criteria including excellence, impact, and implementation quality.

The broader objectives of the call include enabling certification pathways for hydrogen systems in aviation, thus contributing to the EU's climate neutrality goals by 2050. The integration of these systems is crucial for establishing a sustainable aviation industry, leveraging hydrogen as a viable fuel alternative. Collaboration with related projects funded by the Clean Aviation Joint Undertaking is also a requirement to ensure compatibility and synergy among developments in hydrogen propulsion technology. The overall aim is to progress toward a certified and effectively operational hydrogen aviation sector, with potential spill-over benefits for other industrial applications.

The HORIZON-JU-CLEANH2-2026-03-02 call, titled "Components Development and Experimental Testing for an Onboard Liquid Hydrogen Supply and Conditioning System in High-Power Fuel Cell Aviation Applications," is part of the Horizon Europe program and is managed by the Clean Hydrogen Joint Undertaking (JU). It aims to foster the development and validation of key components for liquid hydrogen (LH2) supply and conditioning systems specifically designed for fuel cell-powered electric propulsion in aircraft. The call seeks to improve the reliability and safety of these components, contributing to the broader adoption of hydrogen as a sustainable aviation fuel.

The expected outcomes of this call are:

Paving the way to define integrable and certifiable architectures for liquid hydrogen storage, supply and conditioning systems for regional aircraft.

Paving the way to demonstrate a flightworthy hydrogen supply and conditioning system for regional aircraft (up to 10 MW power class) using liquid hydrogen and fuel cells.

Facilitating cross-sectoral collaboration and knowledge transfer, supporting industry-related skills and enhance awareness, acceptance and fuel cell systems uptake.

Developing a regulatory framework for widespread use of large hydrogen cryogenic technology and fuel cell systems.

The project results are expected to contribute to the following objectives and 2030 KPIs of the Clean Hydrogen JU SRIA:

Enabling continuous hydrogen mass flow in civil aircraft of up to 280 g/s (peak power) and 170 g/s (cruise flight) for up to 10 MW propulsive power. Depending on the system architecture the hydrogen mass flow can be provided by multiple LH2-tank and LH2 supply and conditioning systems.

Achieving a gravimetric index above 30 % for the entire onboard fuel storage, supply and conditioning system. The defined system boundary includes the cryogenic storage tank (including stored hydrogen), piping, venting, supply and conditioning systems.

Achieving an operational index of one aircraft-on-ground (AOG) events to a maximum of one per 3000 flight hours for the entire onboard fuel storage, supply and conditioning system.

The scope of this topic involves designing, developing, and demonstrating the reliable and safe operation of key components and integrated subsystems for LH2 systems. The technology readiness levels (TRL) targeted are TRL 5 for components and TRL 4 for integrated subsystems. Components of interest include, but are not limited to:

Cryogenic valves

Insulation

Piping

Sensors

Metering systems

Interfaces between the tank and the fuel cell systems

The call emphasizes the importance of simulation and experimental component analysis. Simulations should complement component development by providing tools and methods to derive control strategies, optimize operating conditions, optimize thermodynamic integration, and assess performance impacts at the aircraft system level. These simulations should encompass component, subsystem, and system modeling, analyzing thermo-fluid-dynamic behavior, dynamics, and energy flows from hydrogen onboard storage to hydrogen conversion in fuel cells.

The project should address the following:

Development and validation of sizing- and simulation tools for hydrogen supply components design tailored to application specific requirements.

Identification of mass sensitivity for hydrogen supply system components enabling further mass reduction. Exploration of potential indirect weight reductions in other systems by using cooling power availability during evaporation and heat up of liquid hydrogen.

Reduction of aerodynamic drag associated with heat exchange surfaces for in-situ hydrogen evaporation. Consideration of secondary coolant specifications to optimise the heat exchanger in realistic conditions, while maximising potential use of the available cooling.

Evaluation of component performance across all operating phases in connection with liquid hydrogen and fuel cell powertrains using simulation tools.

Development of control strategies for the hydrogen supply and conditioning system relevant for the testing purpose as well as for an hydrogen powered aircraft[2] (HPA) mission profile.

The development of components shall be complemented by experimental system analysis - preferably at research facilities or with support from industrial partner - in combination with a high-power fuel cell system, within a relevant system architecture and power class. Leveraging available infrastructure is expected to provide operational experience under dynamic and mission-relevant conditions, allowing early identification of system-level challenges. These insights will inform and improve component-specific development beyond what could be achieved through systems engineering alone. In parallel, developed components are expected to undergo individual qualification to ensure performance and reliability. These activities contribute to establishing safe, certifiable, and aviation-ready subsystem maturity.

Demonstrate hydrogen supply and conditioning component and sub-system operations under application relevant conditions and evaluate responses to system-level failure cases and dynamic constraints.

Address the durability of materials, components and sub-systems under representative environmental- and mission relevant conditions, including cleanliness and fluid purity sensitivity of the components.

The component development work and the broader sub-system analysis (simulation and experimental testing) are expected to contribute to light weight, energy efficient and low-maintenance designs. The analysis should explore enabling factors (smart topologies, reduction of components & sensors) to achieve such designs, relevant but not limited to the component-level improvements. With system analysis and simulation, critical safety aspects (e.g. failure scenarios, leakage risks, purity effects) are also expected to be assessed.

Scientific analyses and innovation activities should aim to explore the scientific and technological foundations that support safe, certifiable, and high-performance hydrogen supply systems:

Perform safety and failure mode, effects and criticality analysis in alignment with aviation standards.

Consider safety requirements for liquid hydrogen supply components: perform review of available liquid hydrogen fueling safety knowledge, prioritise potential incident scenarios, identify and address safety knowledge gaps, propose safety solutions` strategies. Where appropriate based on engineering and development needs, complement these activities with a detailed quantitative risk analysis and derive applicable risk management measures (including safety devices).

Enablement of robust and safe fuel cell operation in aviation environments.

Validation of hydrogen leakage rates considering both safety and climate impact.

Conduct scientific analyses of the potential cooling systems optimisation/reduction by using cooling power available during evaporation and heat-up of liquid hydrogen.

The call encourages building upon insights from previous Clean Hydrogen JU and Clean Aviation JU projects, such as ELVHYS, HEAVEN, BRAVA, COCOLIH2T, HEROPS, NEWBORN, FAME, and H2ELIOS.

A key requirement is enhanced cooperation with the project funded under the Clean Aviation topic “HORIZON-JU-CLEAN-AVIATION-2026-04-HPA-02” to ensure proper exchange of information, hardware, and intellectual property for component testing activities.

The development of cryogenic tanks and fuel cell systems themselves are explicitly excluded from the scope of this call.

The call specifies that R&D activities should be scalable and transferable to aviation and potentially present positive spill-over effects with other heavy-duty applications. Projects should outline how the developed components could also enable positive spill-over effects for hydrogen combustion in aviation, supporting broader hydrogen use cases across propulsion technologies. Projects should justify proposed budgets based on component/system test size, test duration, and TRL objectives. Innovation activities should clearly define the novel aspects and demonstration scale. Collaboration across relevant stakeholders and end users (e.g., aircraft manufacturers, fuel cell and hydrogen technology developers, certification bodies) is encouraged. While formal certification is not required within this call, proposals should demonstrate how their results and activities support future certification processes and compliance with relevant aviation standards.

The JU estimates that an EU contribution of maximum EUR 8.00 million would allow these outcomes to be addressed appropriately.

The call follows a single-stage submission process. The planned opening date is February 10, 2026, and the deadline for submission is April 15, 2026, at 17:00 Brussels time.

The type of action is a HORIZON JU Research and Innovation Action (HORIZON-JU-RIA), and the Model Grant Agreement (MGA) will be a HORIZON Lump Sum Grant [HORIZON-AG-LS].

General conditions for participation include admissibility conditions related to proposal page limits and layout, eligibility of countries as defined in Annex B of the Work Programme General Annexes, and adherence to financial and operational capacity and exclusion criteria as described in Annex C.

A key aspect of this call is the emphasis on collaboration and synergy between the Clean Aviation JU and Clean Hydrogen JU. The selected project must actively coordinate with the Clean Aviation JU project to ensure compatibility and integration of developed components.

In summary, this call aims to advance the development of liquid hydrogen supply and conditioning systems for aviation fuel cell applications. It emphasizes component-level innovation, system integration, safety, and collaboration between key stakeholders. The projects funded under this call are expected to contribute significantly to the development of a sustainable and certifiable hydrogen-powered aviation sector.

Eligible Applicant Types: The call is open to a range of eligible applicants, including but not limited to research institutions, industrial partners, SMEs, and other relevant stakeholders from Member States of the European Union and Associated Countries. The specific eligibility criteria are detailed in Annex B of the Work Programme General Annexes. Membership in Hydrogen Europe or Hydrogen Europe Research may be an additional eligibility criterion for certain topics.

Funding Type: The funding type is a grant, specifically a HORIZON JU Research and Innovation Action (RIA) under the Horizon Europe program. The grants will be awarded as lump sums.

Consortium Requirement: The opportunity requires a consortium of multiple applicants. For certain topics, one partner in the consortium must be a member of either Hydrogen Europe or Hydrogen Europe Research.

Beneficiary Scope (Geographic Eligibility): The target countries for subcontracting are all Member States of the European Union and all Associated Countries. A number of non-EU/non-Associated Countries that are not automatically eligible for funding have made specific provisions for making funding available for their participants in Horizon Europe projects.

Target Sector: The program targets the aviation sector, specifically focusing on the development and integration of hydrogen fuel cell technology for electric propulsion in regional aircraft. It also encompasses the broader hydrogen technology sector, including cryogenic technology, fuel cell systems, and related components.

Mentioned Countries: The target countries are all Member States of the European Union and all Associated Countries.

Project Stage: The project targets technology readiness levels (TRL) 4 and 5. Key components are expected to reach TRL 5, while integrated subsystems should reach TRL 4 by the end of the project.

Funding Amount: The JU estimates that an EU contribution of maximum EUR 8.00 million would allow these outcomes to be addressed appropriately. However, the budget varies by topic.

Application Type: The application type is an open call with a single-stage submission process.

Nature of Support: Beneficiaries will receive money in the form of lump sum grants.

Application Stages: The application process involves a single stage.

Success Rates: The success rates are not explicitly mentioned in the provided text.

Co-funding Requirement: Co-funding is expected, particularly for actions performed at high TRL level, including demonstration in real operational environment and with important involvement from industrial stakeholders and/or end users such as public authorities.

Summary: This funding opportunity, under the Horizon Europe program and managed by the Clean Hydrogen Joint Undertaking, aims to foster the development and experimental testing of key components for onboard liquid hydrogen (LH2) supply and conditioning systems in high-power fuel cell aviation applications. The goal is to enable the use of cryogenically stored hydrogen as a viable energy carrier for commercial aircraft, particularly regional aircraft powered by fuel cells. Projects should focus on designing, developing, and demonstrating the reliable and safe operation of components such as cryogenic valves, insulation, piping, sensors, metering systems, and interfaces between the tank and the fuel cell systems. A strong emphasis is placed on collaboration between projects funded under this call and those funded under the Clean Aviation Joint Undertaking to ensure system-level compatibility and integrated testing. The funding is provided as a lump sum, and projects are expected to achieve TRL 5 for components and TRL 4 for integrated subsystems. The maximum EU contribution is estimated at EUR 8.00 million per project, and consortia are expected to include partners from EU Member States and Associated Countries. This initiative seeks to pave the way for certifiable liquid hydrogen storage, supply, and conditioning systems, contributing to the broader objectives of clean aviation and the widespread adoption of hydrogen technologies.