In 2026, the H2REF-DEMO project will demonstrate and test its hydrogen compression technology, advancing towards the delivery of reliable hydrogen refuelling systems for heavy-duty vehicles.
Europe’s transition to a net-zero economy depends on clean, reliable hydrogen infrastructure capable of supporting both light and heavy-duty mobility. To enable the hydrogen sector to thrive and meet the demands of the future, there is a clear need for continued investment, research, and innovation in hydrogen technologies. An example of such research and innovation is the H2REF-DEMO project, which aims to develop cost-effective and reliable hydrogen fuel cell vehicle refuelling systems.
Demonstration: From laboratory to full-scale prototype
H2REF-DEMO is co-ordinated by the French Technical Center for Mechanical Industries, CETIM, and will run for a total of 42 months (2023–2026). The project brings together industry leaders and research institutes to validate a hydraulic compression and refuelling system capable of delivering hydrogen at unprecedented flow rates of 150 kg per hour, with consumption below 3.5 kWh per kilogram.
In its final year, the project will install and test a full-scale hydrogen refuelling prototype at its dedicated HRS station in Champagnier (FR), where it will refuel heavy trucks under real-world conditions. Through 500 hours of testing, the one-year campaign will validate both the mechanical durability of the compression system and the operational reliability of the integrated hydrogen refuelling station, aiming to reach Technology Readiness Level 7 (TRL 7). This milestone will mark the transition from laboratory innovation to commercial-scale deployment, showcasing on a large scale how the high-capacity compression module can compress or distribute hydrogen.
The H2REF-DEMO system targets 35 MPa (350 bar) dispensing at 150 kg H₂/h, supporting up to 1.2 tonnes per day of hydrogen throughput. Optimised for on-site production and distribution, the prototype demonstrator achieves an energy efficiency of less than 3.5 kWh/kg – a significant improvement over traditional mechanical compression.
The innovative ‘direct filling’ process is one of two major innovations recognised by the European Commission’s Innovation Radar as having high market potential and a Tech Ready maturity level.
Targeting the heavy-duty transport sector
Co-funded by the Horizon Europe programme under the Clean Hydrogen Partnership (Grant Agreement No. 101101517), H2REF-DEMO builds on the proven success of the original H2REF project (2015–2019), which developed a breakthrough compression concept for passenger vehicle refuelling. Now, the H2REF DEMO project is targeting the heavy transport sector, demonstrating hydraulic compression for high-capacity H2 refuelling, where large vehicles require hydrogen to be dispensed at hundreds of kg/h.
Heavy-duty vehicles cause a significant percentage of the harmful gas emissions attached to the automotive industry. To tackle this challenge, Europe is accelerating its efforts to promote hydrogen as a fuel that can play a key role in the decarbonisation of heavy-transport vehicles. The H2REF-DEMO project is contributing to these efforts, addressing the issue of hydrogen refuelling.
Modular advancements
Along with capacity scale-up, the demonstrator focuses on process optimisation, cost reduction, and further durability testing. Full optimisation will be achieved by first developing a digital twin of the scaled-up process.
Key finalised modules of the demonstrator include:
- Hydraulic Power Pack (HPP), which provides the power to hydraulic blader accumulators. The HPP is tested and ready to be installed at the HRS demonstration site.
- High-Capacity Compression Module (HCCM): This is designed for seamless integration with hydrogen storage systems and dispensers. The HCCM achieves flow rates of 150 kg of hydrogen per hour, setting new benchmarks for efficiency in heavy-duty fuelling.
- Hydraulic Bladder Accumulator System: This innovative design replaces traditional mechanical compressors with a bladder accumulator-based approach. This shift enables greater reliability, performance, and energy efficiency, which are crucial for meeting the demanding requirements of heavy-duty transport.
- Advanced Bladder Materials: Research into durable materials, such as epichlorohydrin rubber (ECO) and hydrogenated nitrile rubber (HNBR), is pivotal for ensuring compatibility with hydrogen while adhering to stringent environmental regulations.
- Composite Reinforced Accumulator Shells: Developed by partner companies FABER and HYDAC, these new shells combine steel liners with carbon-fibre reinforcement, significantly enhancing safety and longevity.
From digital twin to real-world demonstration
To simulate performance before hardware testing, the H2REF-DEMO team has created a digital twin of the whole compression and distribution process. This model enables, at an initial stage, the dimensioning of the system’s various components and, at a second stage, the real-time optimisation of parameters such as flow rate, temperature, and pressure loss – helping to fine-tune operations for efficiency and safety.
Now in its second year, the project has made significant progress so far. One major focus has been the testing and development of durable, hydrogen-compatible bladder materials. The project has explored multiple elastomeric compounds – notably epichlorohydrin rubber (ECO) and hydrogenated nitrile rubber (HNBR) – to replace PFAS-based formulations phased out under new EU regulations.
At the same time, FABER and HYDAC have engineered new accumulator shells, combining steel liners and carbon-fibre reinforcement for safety and longevity. Testing regimes include burst, fatigue, and hydrostatic trials exceeding 50,000 cycles, confirming structural integrity under extreme conditions.
Meanwhile, Hydraulic Power Pack HPP (CETM) and High-Capacity Compression Module HCCM (HRS) were developed, and their integration work has just started. The system’s safety has been validated through a full Failure Mode and Effects Analysis (FMEA), ensuring CE compliance for eventual market deployment.
A joint effort to drive the clean hydrogen vision
H2REF-DEMO’s consortium consists of seven partners across three EU countries, each contributing unique expertise:
- CETIM: Project coordinator, hydraulic power system design and testing.
- HYDAC: Bladder accumulator design and material innovation.
- H2NOVA: Dissemination, industrial integration, and exploitation.
- HRS: Hydrogen refuelling station design and demonstration.
- FABER: Manufacturing of high-pressure vessels.
- UNIMORE and UTC: Advanced modelling, digital twin development, and system analysis.
Impact: Fuelling Europe’s hydrogen mobility
Once validated, the H2REF-DEMO system promises to reduce energy consumption, operational costs, and maintenance needs across the hydrogen refuelling chain. Its modular architecture enables deployment in diverse settings — from urban bus depots to motorway freight corridors – supporting Europe’s Fit for 55 and REPowerEU objectives.
Beyond its technical achievements, the project sets an important precedent for sustainable manufacturing. By eliminating PFAS materials and optimising hydraulic components for longevity, H2REF-DEMO contributes to both environmental responsibility and industrial resilience within the EU hydrogen sector.
Towards a scalable hydrogen future
As the project moves toward its final demonstration phase, H2REF-DEMO embodies Europe’s collective ambition: to build robust, efficient, and sustainable hydrogen refuelling infrastructure that can power the heavy transport sector. By advancing hydrogen compression to commercial readiness, the consortium is not just refining a technology – it’s laying the groundwork for a cleaner, interconnected, and self-reliant energy future.
H2REF-DEMO project is co-funded by the European Union’s Horizon Europe programme under the Clean Hydrogen Partnership
(grant agreement No. 101101517)
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