Innovative light weight and reliable liquid hydrogen tank

This Clean Aviation Joint Undertaking Research and Innovation Action finances development and TRL4 demonstration of an innovative lightweight, reliable liquid hydrogen tank for aircraft integration, targeting a gravimetric index of at least 40 percent and dormancy of at least 12 hours validated by on‑ground cryogenic and tightness testing. The call is single-stage with planned opening on 31 March 2026 and a submission deadline of 19 May 2026 at 17:00 Brussels time. Eligible applicants are consortia of legal entities established in EU Member States or Horizon Europe Associated Countries in line with Horizon Europe and CAJU rules, typically with at least three independent partners. Indicative EU contribution is around €5 million per project under the Horizon Action Grant budget-based model with a funding rate of up to 100 percent for RIAs.

Opportunity Overview

Innovative light weight and reliable liquid hydrogen tank (HORIZON-JU-CLEAN-AVIATION-2026-04-FTA-07)

What it funds

Research and Innovation Action to develop and demonstrate an innovative lightweight, reliable liquid hydrogen aircraft tank concept to TRL4, including on‑ground cryogenic and tightness testing demonstrating a gravimetric index ≥ 40% and dormancy ≥ 12 hours. Activities must address safety, certification readiness and integration into hydrogen‑powered aircraft concepts.

Who can apply:Consortia of legal entities established in EU Member States and Horizon Europe Associated Countries in line with CAJU/Horizon Europe eligibility rules; typical applicants include aerospace OEMs, tier suppliers, universities, research organisations and test facilities. CAJU rules on admissibility, ethics, security and financial capacity apply.

Type of action and TRL:HORIZON-JU-RIA (Research & Innovation Action). Target Technology Readiness Level: TRL4 demonstration (ground cryogenic & tightness tests).

Key technical targets:Gravimetric index no less than 40% and dormancy no less than 12 hours demonstrated under ground test conditions; design must be suitable for aircraft integration and address safety and certification readiness.

1. 1Call opening planned: 31 March 2026 (submission system and templates available on Portal)
2. 2Deadline (single‑stage): 19 May 2026, 17:00 Brussels time
3. 3Action type: CAJU HORIZON-JU-RIA (Fast Track Activity/FTA)

Funding and contractual framework: CAJU (Clean Aviation) call under Horizon Europe; standard Horizon/CAJU eligibility, ethics, security and grant rules apply. Proposal templates, evaluation forms and model grant agreement will be available in the submission system when it opens; applicants should consult the topic description and General Annexes on the Funding & Tenders Portal.

Footnotes

1. 1The topic is published within the Clean Aviation CfP 04 package whose call-level indicative total contributions are shown on the Funding & Tenders Portal.

Innovative light weight and reliable liquid hydrogen tank — Clean Aviation CfP 04 (HORIZON-JU-CLEAN-AVIATION-2026-04-FTA-07)

This call seeks proposals to develop and demonstrate an innovative lightweight and reliable liquid hydrogen tank concept for integration into hydrogen-powered aircraft concepts. The topic targets demonstration at TRL 4 with a gravimetric index of at least 40 percent and a dormancy of at least 12 hours, to be evidenced through on-ground cryogenic and tightness testing. The action is a Horizon Europe Clean Aviation Joint Undertaking Research and Innovation Action (HORIZON-JU-RIA), single-stage, with opening on 31 March 2026 and deadline on 19 May 2026 at 17:00 Brussels time. Full topic details are provided in the Clean Aviation Work Programme and the topic description published on the EU Funding and Tenders Portal.

Eligibility, Funding, Scope, and How to Apply

Eligible Applicant Types:All standard Horizon Europe-eligible legal entities can participate. Typical applicants include: SMEs and startups (including hydrogen, cryogenics, advanced materials, aerospace systems), large enterprises and aerospace OEMs and Tier-1/2 suppliers, universities and higher education institutions, public and private research organisations, nonprofit organisations and foundations with relevant R&I capacity, government bodies and public authorities (where they meet eligibility criteria), standardisation and testing bodies, and public-private consortia. The European Union Aviation Safety Agency (EASA) may be involved via a separate service contract mechanism to provide advisory services; it is not a beneficiary but costs can be budgeted as other goods and services under the grant using the dedicated CAJU-EASA service contract template.

Funding Type:Grant funding under Horizon Europe via the Clean Aviation Joint Undertaking (HORIZON-JU-RIA). For RIAs, the maximum EU funding rate is up to 100% of eligible costs, subject to Horizon Europe rules and any CAJU-specific conditions.

Consortium Requirement:Unless otherwise specified at topic level, standard Horizon Europe consortium rules apply: a consortium of at least three independent legal entities, each established in a different EU Member State or Associated Country, with at least one in a Member State. The Clean Aviation rules allow a derogation for single applicants where explicitly stated at topic level; no such derogation is indicated in the provided topic text, therefore a multi-beneficiary consortium is expected.

Beneficiary Scope (Geographic Eligibility):Eligibility follows Horizon Europe General Annex B: entities established in EU Member States (including outermost regions), Horizon Europe Associated Countries, and certain low- and middle-income third countries are eligible as specified. Entities in Russia, Belarus, and non-government controlled territories of Ukraine are ineligible; entities subject to EU restrictive measures are ineligible. Additional restrictions (e.g., 5G security toolbox) may apply to specific topics; not applicable here. For Innovation Actions there is an exclusion on entities established in China; this topic is an RIA and not subject to that specific IA restriction.

Target Sector:Aviation and aerospace (hydrogen propulsion enablement), hydrogen storage and systems, cryogenics, safety and certification readiness, advanced materials and composites, structural design and integration, thermal management, manufacturing and testing infrastructure.

Mentioned Countries:The eligibility references explicitly list: EU Member States (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden), Overseas Countries and Territories (Aruba, Bonaire, Curaçao, French Polynesia, French Southern and Antarctic Territories, Greenland, New Caledonia, Saba, Saint Barthélemy, Sint Eustatius, Sint Maarten, St. Pierre and Miquelon, Wallis and Futuna), Associated Countries (Albania, Armenia, Bosnia and Herzegovina, Faroe Islands, Georgia, Iceland, Israel, Kosovo, Moldova, Montenegro, New Zealand, North Macedonia, Norway, Serbia, Tunisia, Türkiye, Ukraine, United Kingdom), and an extended list of low- and middle-income countries eligible for funding per the Horizon Europe General Annexes. Entities established in Russia, Belarus, and non-government controlled territories of Ukraine are currently not eligible.

Project Stage:Research and development to validation. The topic explicitly targets TRL 4 (technology validated in lab) demonstration of a reliable, safe liquid hydrogen tank concept, with ground cryogenic and tightness testing. This corresponds to development and validation stages.

Funding Amount:The total indicative budget published for the Clean Aviation CfP 04 call package is €329,500,000 for 2026 across multiple topics. A specific budget amount per this topic HORIZON-JU is not stated in the provided materials. Under RIAs, eligible costs may be funded up to 100 percent, subject to budget availability and evaluation ranking.

Application Type:Open call, single-stage submission via the EU Funding & Tenders Portal. The submission system opens by end of March 2026. Deadline is 19 May 2026 (17:00 Brussels time).

Nature of Support:Monetary support in the form of a grant. Non-monetary elements include access to guidance, Q&A publications, and optional cooperation/coordination mechanisms (e.g., linked actions across CAJU topics), and optional EASA advisory services via a separate service contract (costs eligible as “other goods and services”).

Application Stages:Single-stage evaluation for this call. Evaluation is conducted by external independent experts and follows the phases: individual evaluation, consensus group, Topic Panel review, and optionally a Call Panel review across topics.

Success Rates:No success rate data is provided for this topic or call in the available materials.

Co-funding Requirement:For RIAs, the EU contribution may cover up to 100 percent of eligible costs. No formal co-funding rate is required, but beneficiaries must finance any ineligible costs and ensure cash flow until reimbursements. The no-profit rule applies as per the Model Grant Agreement.

Technical Objectives and Expected Outcomes

• Demonstrate a reliable and safe liquid hydrogen tank concept at TRL 4 suitable for integration into hydrogen-powered aircraft concepts.
• Achieve a gravimetric index of at least 40 percent.
• Achieve a dormancy of at least 12 hours.
• Validate performance via on-ground cryogenic testing and tightness testing.
• Generate evidence to inform downstream integration, safety assessment, and potential certification pathways in alignment with CAJU objectives.

Evaluation and Award Criteria

HORIZON-JU-RIA proposals are evaluated on Excellence, Impact, and Quality and efficiency of the Implementation. Each criterion is scored 0–5; individual thresholds are 3/5 and the overall threshold is 10/15. For RIAs, there is no additional weighting on Impact (weighting is applied only to Impact for IAs). The CAJU Specific Evaluation Template for Fast Track Activities (FTA) applies. Evaluation includes admissibility and eligibility checks, expert review, consensus, Topic Panel review, and optional Call Panel cross-review. Hearings with applicants may be organised if needed during consensus.

Who Can Participate and Key Eligibility Notes

• Standard Horizon Europe participation rules apply (General Annexes A–G).
• Minimum consortium composition under Horizon Europe (three legal entities from three different eligible countries; at least one from an EU Member State), unless a topic-level derogation is explicitly provided in the Work Programme. No such derogation is indicated in the provided text for this topic.
• Eligible countries include EU Member States, Associated Countries, and a list of low- and middle-income countries as specified in Annex B of the General Annexes. Entities from Russia, Belarus, and non-government controlled territories of Ukraine are not eligible to participate in any capacity.
• Entities subject to EU restrictive measures are ineligible.
• Additional protections and restrictions (e.g., 5G cybersecurity Toolbox) are not applicable to this topic.
• Note: For Innovation Actions (not applicable here), entities established in China are not eligible; this topic is an RIA.

Budgeting, Funding Rate, and Legal-Financial Setup

• Type of MGA: Horizon Action Grant (budget-based).
• Funding rate: RIA up to 100 percent of eligible costs.
• Indirect costs: 25 percent flat rate on eligible direct costs (excluding categories specified by the MGA).
• No pre-defined per-topic budget provided in the call text; the CfP 04 package totals €329.5 million (2026).
• Mutual Insurance Mechanism applies as per the Horizon Europe MGA.
• No-profit rule applies; financial viability checks apply to coordinators where applicable; operational capacity is evaluated under Implementation.
• EASA advisory services can be contracted via the Clean Aviation service contract template; costs are eligible under Other goods, works and services in the beneficiary’s budget.

How to Apply and When

• Submission is via the EU Funding & Tenders Portal. Use the forms in the electronic submission system; paper submissions are not accepted.
• Opening: 31 March 2026. Deadline: 19 May 2026 (17:00 Brussels time).
• Single-stage submission; full Part A (administrative) and Part B (technical) must be completed, respecting page limits (45 pages for full RIA applications unless otherwise specified).
• Indicative feedback on evaluation: approximately 5 months after the deadline; indicative grant agreement signature approximately 8 months after the deadline.
• Q&A publications: a first Q&A release is foreseen on 17 February 2026 and a second on 17 April 2026 for the call package.
• Partner search: the Portal allows publication of partner requests for open/forthcoming topics by eligible users.

Application Templates and Structure

Applicants must use the application form available in the Submission System. The following templates and guidance are provided for this call to support proposal preparation and budget structuring:

• Proposal Application Form for this topic (Part A online forms and Part B PDF upload).
• Financial annex templates (mandatory parts of the proposal) including: Estimated budget for the action per reporting period; Work Package description (Detailed); Work Package effort (Detailed); Cost breakdown per beneficiary; Budget summary per applicant and work package; In-kind contribution details.
• CA JU Model Consortium Agreement (recommended to regulate internal consortium relations).
• Clean Aviation service contract template for advisory services by EASA (to be used where EASA involvement is planned).
• CAJU Rules for submission, evaluation, selection, award and review procedures of Calls for Proposals (specific to Clean Aviation JU).
• Evaluation templates (HE RIA/IA standard) with CAJU adaptations for Fast Track Activities (FTA).
• Model Grant Agreement (Horizon Europe), Annotated Model Grant Agreement (AGA), and the Horizon Europe Programme Guide.
• Online Manual and Funding & Tenders Portal Terms & Conditions for procedural and IT guidance.

Work Programme, Legal and Compliance References

• Clean Aviation Work Programme 2026–2027 and Full Description of Topics.
• Horizon Europe Main Work Programme 2026–2027 and General Annexes (A–G).
• Regulation (EU) 2021/2085 establishing the Joint Undertakings under Horizon Europe (Single Basic Act).
• EU Financial Regulation 2024/2509.
• Rules for Legal Entity Validation, LEAR appointment, Financial Capacity Assessment.
• Ethics and security provisions per Horizon Europe; projects must focus exclusively on civil applications.

Notable CAJU-Specific Procedures

• CAJU may request adjustments during Grant Agreement Preparation to strengthen alignment with CAJU objectives and SRIA HLOs, optimise budget, ensure synergies with other actions, and link actions across topics.
• Cooperation Agreements may be required at grant signature to connect selected actions across relevant CAJU topics to foster integrated programmatic approaches.
• Linked actions: CAJU can require linkages to other EU-funded actions or formally set-up activities to ensure portfolio consistency and programme impact.
• Hearings: CAJU may organise applicant hearings during evaluation to clarify technical scope, synergies, and budget optimisation; no proposal changes are permitted, but clarifications can be requested.

What the Topic Expects Technically

• Liquid hydrogen tank concept suitable for integration in hydrogen-powered aircraft concepts.
• Demonstration at TRL 4: technology validated in a laboratory environment.
• Performance metrics: gravimetric index not less than 40 percent; dormancy not less than 12 hours.
• Evidence via on-ground cryogenic performance tests and tightness/leakage tests.
• Safety and reliability at the forefront, in line with prospective regulatory and certification pathways.

Reporting, Payments, and Compliance

• Periodic and final reporting through the Portal; technical (Part B) and financial statements (Part A/Forms C) are required.
• Eligible cost categories follow the Horizon Europe Model Grant Agreement (personnel; subcontracting; purchase costs; other goods, works, services; indirect costs via 25% flat rate).
• Ethics self-assessment is mandatory; projects undergo ethics screening and, where needed, ethics assessment with requirements that may become contractual obligations.
• Data protection, confidentiality, and IP rules follow the Horizon Europe MGA; EU visibility and communication rules apply.
• No-profit rule applies at final payment; revenues must be declared as per MGA.

Contact and Support

• EU Funding & Tenders Portal Online Manual for step-by-step procedures.
• National Contact Points (NCPs) for Horizon Europe (including NCPs in many non-associated third countries).
• Enterprise Europe Network (EEN) for SME-oriented support.
• IT Helpdesk for portal access and submission issues.
• European IPR Helpdesk for intellectual property matters.
• Standards support via CEN-CENELEC and ETSI Research Helpdesks.

Summary Explanation

This Clean Aviation Joint Undertaking topic funds research and innovation actions to design and validate a next-generation liquid hydrogen storage tank for aircraft integration. Proposals must target a lab-validated concept at TRL 4 and meet explicit performance thresholds: a gravimetric index of at least 40 percent and dormancy of at least 12 hours, demonstrated by rigorous ground cryogenic and tightness testing. Applicants should assemble a capable, multi-country consortium across the hydrogen, cryogenics, advanced materials, aerospace structures, testing, and safety domains. The call follows Horizon Europe’s single-stage RIA process under the CAJU rules, with proposals evaluated on excellence, impact, and quality and efficiency of implementation. Budgeting and legal-financial provisions follow the Horizon Europe Model Grant Agreement (up to 100 percent funding of eligible costs for RIAs). CAJU may request adjustments at the grant preparation stage, including alignment with the Strategic Research and Innovation Agenda and linkages with other Clean Aviation actions. The submission is via the EU Funding & Tenders Portal, opening 31 March 2026 and closing 19 May 2026. Comprehensive templates (application forms, financial annexes, model consortium agreement, and an EASA service contract template) are provided to streamline preparation. In essence, this opportunity aims to de-risk, validate, and position breakthrough liquid hydrogen tank concepts for future aircraft integration and certification pathways, thereby accelerating the transition to climate-neutral aviation technologies.

Innovative Lightweight and Reliable Liquid Hydrogen Tank - HORIZON-JU-CLEAN-AVIATION-2026-04-FTA-07

Opportunity Overview

This Research and Innovation Action (RIA) under the Clean Aviation Joint Undertaking (CAJU) Call for Proposals 04 targets the development and demonstration of an innovative lightweight and reliable liquid hydrogen tank concept for integration into hydrogen-powered aircraft. The primary goal is to achieve Technology Readiness Level (TRL) 4 for a safe hydrogen tank design with a gravimetric index of at least 40% and dormancy of at least 12 hours, validated through on-ground cryogenic and tightness testing. Full technical details are provided in the topic description document accompanying the call.

Key Objectives and Expected Outcomes

The project must demonstrate a reliable and safe hydrogen tank design suitable for hydrogen-powered aircraft concepts. Key performance targets include: gravimetric index no less than 40% and dormancy no less than 12 hours. Validation occurs via on-ground cryogenic and tightness testing at TRL4. This supports Clean Aviation's Strategic Research and Innovation Agenda (SRIA) for hydrogen propulsion technologies.

Timeline:Planned opening: 31 March 2026. Single-stage submission deadline: 19 May 2026, 17:00 Brussels time. Submission system opens end of March 2026.

Eligibility and Who Can Apply

Open to legal entities forming a consortium of at least three independent legal entities from different EU Member States or Associated Countries (at least one from an EU Member State). Single entities or consortia not meeting the minimum condition may be eligible if specified in the topic. Eligible countries follow Horizon Europe Annex B. Non-EU entities from low/middle-income countries may be eligible for funding if essential. Private members of CAJU (Founding and Associated Members) are expected to contribute substantially.

Evaluation Criteria

• Excellence: Clarity of objectives, soundness of methodology, interdisciplinary approaches, gender dimension, open science.
• Impact: Pathways to expected outcomes, dissemination/exploitation plans, communication.
• Quality and efficiency of implementation: Work plan effectiveness, risk assessment, consortium capacity.

Thresholds: 3/5 per criterion, overall 10/15. Specific Clean Aviation evaluation template for Fast Track Activities (FTA) applies. CAJU Specific Rules for submission, evaluation, selection, award and review procedures also apply.

Funding Details

Budget:Indicative EU contribution: €5 million per project (one project expected). Total Call 4 budget: €329.5 million across 18 topics. Type of MGA: HORIZON Action Grant Budget-Based (HORIZON-AG). Funding rate: 100% for RIA.

Proposal Templates and Financial Annexes

Available now on the Funding & Tenders Portal for preparation. Includes: Proposal Application Form, detailed budget templates (estimated budget per reporting period, work package descriptions, cost breakdown per beneficiary, budget summary, in-kind contributions), CAJU Model Consortium Agreement, EASA service contract template.

Application Process

1. 1Register in Participant Register and validate PIC.
2. 2Prepare proposal using templates (page limits per General Annexes).
3. 3Submit electronically via Funding & Tenders Portal (single-stage).
4. 4Check Topic Q&As (first release 17 February 2026, second 17 April 2026).
5. 5Evaluation: Individual, consensus, topic panel, possible call panel review.
6. 6Indicative timeline: Evaluation results ~5 months post-deadline, grant agreement ~8 months.

Specific Conditions and Documents

Admissibility: Proposal page limits/layout per Annex A/E. Eligibility: Annex B. Financial/operational capacity: Annex C. Award criteria: Annex D (CAJU FTA template). Submission processes: Annex F. Legal/financial set-up: Annex G. Clean Aviation specific rules apply. Documents: Full topic descriptions, CAJU Work Programme 2026-27, HE Work Programmes, Programme Guide, Model Grant Agreements.

Support and Resources

• Partner Search on Portal.
• National Contact Points (NCPs), Enterprise Europe Network (EEN).
• IT Helpdesk, Research Enquiry Service, European IPR Helpdesk.
• Online Manual, HE Programme Guide.
• Q&A process: Submit via functional mailbox, two releases planned.

Key Considerations for Applicants

Focus on TRL4 demonstration with strict performance metrics. Strong consortium with CAJU private members recommended. Prepare for EASA collaboration on certification. Monitor portal for updates on templates and Q&As. Ensure compliance with Horizon Europe General Annexes and CAJU-specific rules. Proposals exceeding page limits will have excess pages blanked.

Primary source: EU Funding Portal. Check regularly for topic updates and document changes.

Footnotes

1. 1Indicative funding per topic from preliminary list; final amounts confirmed in call publication. Gravimetric index and dormancy targets from topic description.