A major EU-funded project will test hydrogen engines on a large commercial vessel for the first time, marking a significant step toward decarbonising long-distance shipping. The H4PERION (Hydrogen FOR Performance Enhancement and Reliable Ice OperatioN) initiative, coordinated by the University of Vaasa, has secured €11.2 million from the European Union’s Horizon Europe programme until 2030. Of that total, €3.2 million is allocated to the university.
Project goal and challenges
The project aims to demonstrate how a hydrogen-capable internal combustion engine (ICE) can operate safely and reliably on a large oceangoing ship. Long-distance shipping remains one of the hardest sectors to decarbonise: vessels that sail for weeks at a time require vast amounts of energy and absolute reliability, which today’s batteries and fuel cells cannot yet provide at scale. At the same time, global climate regulations are tightening. The International Maritime Organization’s 2023 GHG strategy targets net-zero emissions from international shipping by or around 2050, with indicative checkpoints of at least 20–30% reduction by 2030 and 70–80% by 2040, compared with 2008 levels. The EU is also pushing forward with measures such as FuelEU Maritime, which sets progressively stricter GHG intensity reduction targets for ship energy use, the extension of the Emissions Trading System to shipping since January 2024, and the Alternative Fuels Infrastructure Regulation with mandatory deployment targets.
“Several low-carbon fuels are being explored within the industry, and hydrogen is considered one potential zero-carbon option. It produces no carbon emissions and can be used in familiar, reliable and fuel-flexible internal combustion engines, enabling a future-proof solution for decarbonisation to vessel owners. Yet hydrogen engines have not previously been demonstrated on large vessels, and key questions remain around fuel handling and supply, safety and regulations,” said Henri Karimäki, Research and Development Director at the University of Vaasa.
Technical innovations
H4PERION combines three major innovations. The first is a new engine concept capable of running on hydrogen and biomethane, with the long-term goal of full hydrogen operation. The University of Vaasa is exploring an advanced combustion strategy known as Reactivity Controlled Compression Ignition (RCCI). This dual-fuel approach aims to reach a net efficiency of 55% with near-zero emissions when combined with fully variable valve actuation and advanced aftertreatment solutions. Research on RCCI for marine engines has indicated efficiencies of up to 47.8% with stock hardware and potential for 52% with optimised components, while delivering ultra-low NOx and soot emissions. “This combustion concept is considered a promising way to integrate green hydrogen flexibly into existing natural gas and biogas supply chains. Achieving the targeted efficiency within the project timeline requires deep integration of simulation and testing environments with autonomous calibration routines,” said Maciej Mikulski, Professor of Energy Technology at the University of Vaasa.
The second innovation is a modern fuel blending and supply system that allows flexible use of zero-carbon fuels. The third is a new exhaust aftertreatment approach designed to clean emissions across all operating conditions.
The technologies will be installed and tested on the Aurora Botnia, a roll-on/roll-off passenger (ro-pax) ferry operated by Wasaline on the Vaasa–Umeå route. The vessel, which entered service in August 2021, is 150 metres long and 26 metres wide with a draught of 6.1 metres. It carries up to 935 passengers and has 1,500 lane metres for trailers and cars. Its propulsion system features four Wärtsilä 8V31DF dual-fuel engines capable of running on liquefied natural gas (LNG), biogas, and a battery system. The ferry was awarded a Clean Design class certificate by DNV and was advertised as “the world’s most environmentally friendly ferry” at launch. By 2026 the Aurora Botnia is scheduled to have a 12 MWh battery and be supplied solely with liquid biogas.
Wärtsilä, a key partner in the project, has already tested hydrogen blends in unmodified engines. The company demonstrated that its Wärtsilä 50SG engine can operate with a 25% hydrogen blend, achieving improved efficiency and reduced greenhouse gas emissions. It has also launched the world’s first large-scale 100% hydrogen-ready engine power plant, based on the Wärtsilä 31 platform, which can be converted to run on pure hydrogen. Orders for that technology are expected from 2025, with deliveries from 2026. The Wärtsilä 31 platform is the most efficient engine of its type globally.
In parallel with the onboard demonstration, an identical full-scale engine will be tested in a laboratory environment to mirror real sailing conditions and optimise performance. Data from both will feed into a digital twin model to support long-term learning and future design. “H4PERION is about turning promising fuel concepts into solutions that can be operated safely at sea. By combining full-scale engine development with onboard demonstration and digital modelling, we can shorten the path from research to real-world impact for low- and zero-carbon shipping,” said Anders Öster, General Manager for Research Coordination and Funding at Wärtsilä Marine.
The project will also produce open training materials for crew and port operators, contribute to safety guidelines and regulatory development, and explore how the technologies can be applied to different vessel types. Safety is a critical concern: hydrogen has a wide flammability range, low minimum ignition energy, and can embrittle certain materials. A multi-year study by DNV for the European Maritime Safety Agency recommends a design-based safety approach for hydrogen-fuelled vessels, including secondary enclosures for all hydrogen-carrying components. The International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code) provides a framework for fuels like LNG but does not yet fully address hydrogen-specific risks. Crew training will be essential to identify and mitigate those hazards.
Collaborative effort
H4PERION brings together 16 partners from seven European countries, representing the full maritime value chain from ship design and engine development to vessel operation, training, safety and academic research. The consortium includes, alongside the University of Vaasa as coordinator, Wärtsilä, WEGEMT, NTUA, TalTech, the American Bureau of Shipping, Deltamarin, the University of Oulu, Åbo Akademi University, Meric Wave Computanics, DLR, BALance Technology Consulting, MEYER WERFT and Wasaline. For the Vaasa region, the project showcases local strength: the University of Vaasa, Wärtsilä and Wasaline all play central roles. The university, a multidisciplinary business-oriented institution with a focus on energy and sustainable development, operates the Vaasa Energy Business Innovation Centre (VEBIC) and has established a European Office in Brussels to foster links between research, industry and policymaking.
The project directly addresses the challenges of decarbonising long-distance shipping, where high fuel costs, infrastructure gaps, regulatory uncertainty and long vessel asset lives remain significant hurdles. By demonstrating hydrogen ICE technology on a large vessel, H4PERION aims to provide practical evidence that can accelerate the transition to zero-carbon maritime operations.
