Hydrogen ships are emerging as one of the most promising solutions to decarbonize maritime transport.
At a time when the need to reduce emissions aligns with new international regulations, the maritime industry is actively seeking solutions to minimize its environmental impact.
Maritime traffic is currently responsible for around 3% of total global greenhouse gas emissions. This share could rise to 10% by 2050 if effective action is not taken.
Within this context, the spotlight is on the industry’s ability to develop new technologies that enable decarbonization. From ships adapted for Liquefied Natural Gas (LNG) to ammonia and methanol, multiple alternatives are being considered. Among them, hydrogen ships stand out thanks to their zero-emission potential through the use of green hydrogen.
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This scenario is being shaped by collaborative efforts across various sectors, where cryogenic engineering plays a key role in enabling the use of hydrogen fuel. Let’s explore how!
Hydrogen ships: what are they and how do they work?
Hydrogen powered ships are vessels that use hydrogen as an energy source.
This highly innovative vessel type already includes iconic examples such as the Energy Observer, described by its creators as “the first hydrogen-powered and zero-emission ship that is energy self-sufficient”.
Hydrogen as a sustainable alternative
Hydrogen boats are poised to help solve the challenge of decarbonizing the shipping industry. That’s because using green hydrogen as fuel offers access to a clean energy source, since:
- It produces zero CO₂ and nitrogen oxide emissions, its only byproduct is water vapor.
- It can be generated via electrolysis from water, making it a renewable energy option that reduces dependence on fossil fuels.
However, the development of hydrogen powered ships still faces key challenges, such as:
- Higher costs compared to other fuels. Green hydrogen production must fall to about a third of its current cost to be competitive.
- Infrastructure limitations, including the availability of refueling stations at ports and the complexity of hydrogen supply chains.
- The need for dedicated storage solutions, such as cryogenic tanks for liquid hydrogen.
Despite these hurdles, the potential of hydrogen transport by sea is significant, and a wide range of global stakeholders are actively working to overcome them.
Government initiatives are also emerging to facilitate the rollout of green hydrogen.
Together, these actions are paving the way for hydrogen to become a foundational element in sustainable maritime transport in the coming years.
Explore our project: Cryospain project: Liquid Hydrogen power for cleaner shipping
Types of propulsion in hydrogen ships
Currently, there are two main types of propulsion systems being explored for hydrogen powered ships:
- Fuel cells, which convert hydrogen into electricity to power electric motors. In this process, hydrogen reacts with an oxidizing agent like oxygen, producing only water, heat, and electricity. This technology is already being used in prototypes and various vessels, including ferries, passenger ships, and submarines.
- Adapted internal combustion engines, creating hydrogen engines. This method allows for the use of existing engine technology but offers lower energy efficiency than fuel cells.
As explained below, liquid hydrogen plays a key role in powering both propulsion systems. Stored at cryogenic temperatures (-253 °C), it provides higher energy density than compressed or gaseous hydrogen, making it suitable for ships with high energy demands.
Benefits of hydrogen ships
Emission reduction in maritime transport
Decarbonizing the maritime sector is an urgent need. Projections by the EU estimate that shipping emissions could increase by 130% over 2008 levels by 2050, positioning the sector as a major player in climate change mitigation.
However, there’s also room for optimism. According to the International Transport Forum report “Decarbonising Maritime Transport: Pathways to zero-carbon shipping by 2035”, using clean fuels, combined with efficiency improvements and operational changes, could reduce emissions by 82% to 95% by 2035 compared to business-as-usual scenarios.
Alternative fuels such as methanol, ammonia, and LNG are all key allies in this transition, yet hydrogen fuel stands out for producing only water vapor as emissions.
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Decarbonization of the shipping industry
Hydrogen powered ships represent a strategic solution to achieve deep decarbonization of the shipping sector. Their adoption not only mitigates the environmental impact of maritime transport but also aligns with climate targets set by international organizations.
Compliance with international regulations
Hydrogen ships also play a vital role in ensuring compliance with international maritime regulations, such as those established by the International Maritime Organization (IMO). In particular, the 2023 GHG strategy from IMO requires a 40% reduction in maritime emissions by 2030.
This push has already catalyzed innovations in ship propulsion, such as converting vessels to LNG-powered ships.
The role of cryogenics in hydrogen ships
The development of hydrogen powered boats depends on technological advancements where cryogenic engineering is essential.
One of the key requirements is the design of onboard storage and transport systems for liquid hydrogen, which is crucial for powering medium and large commercial vessels. Let’s take a closer look:
Cryogenic storage technologies
Cryogenic tanks for liquid hydrogen enable highly efficient storage, allowing the transport of larger volumes in minimal space.
To achieve this, the systems must maintain temperatures below -253 ºC, minimizing evaporation losses. This calls for precise cryogenic engineering that ensures effective insulation, along with safety systems to prevent material damage or accidents. In marine environments, anti-corrosion requirements must also be met.
These cryogenic storage tanks are supported by specialized components, such as insulated piping and cryogenic valves.
This cryogenic infrastructure must extend beyond ships to ports, requiring collaboration among all stakeholders in the maritime transport sector.
Cryogenic applications in maritime transport
Beyond enabling the use of liquid hydrogen fuel, cryogenic engineering also supports other advances toward maritime decarbonization.
One example is LNG-powered ships, which use cryogenic LNG storage (-162°C). With established infrastructure and mature technology, LNG serves as a transition fuel on the path to zero-emissions shipping.
These vessels rely on cryogenic tanks and auxiliary systems such as vaporization and reliquefaction units, enabling the safe and efficient use of LNG.
Cryospain: enabling the safe transport of hydrogen
At Cryospain, we bring more than two decades of expertise in cryogenic engineering to support the maritime sector’s decarbonization.
We lead retrofit projects by designing, manufacturing, and installing vacuum-insulated cryogenic piping systems to transport hydrogen safely inside ships.
This process involves:
- 3D design of vacuum-insulated cryogenic pipe sections
- Finite element analysis to ensure structural integrity under operating pressures and temperatures
- In-house fabrication of cryogenic piping to guarantee the highest quality standards
- On-site installation at shipyards, including vacuum creation and commissioning
- Helium leak testing and pressure testing
By doing so, Cryospain helps maritime operators meet IMO 2023 requirements with full safety and reliability, while also complying with RINA quality certification standards.
We have the technology and experience to deliver vacuum-insulated pipes fully tailored to the needs of each project.
Want to learn more about hydrogen ships and how cryogenic engineering can accelerate your maritime decarbonization project?
Get in touch with us and speak to Cryospain experts about how we can help you!
