Engineering a practical hydrogen storage system for maritime use
Hydrogen has significant potential as a clean fuel for maritime vessels but storing it at sea remains a major technical challenge.
NCC is part of a UK-Australian collaboration working to address this, through the Hydrogen Zero Emission Maritime (HyZEM) project.
Funded by Innovate UK and the Australian Government, the project brings together materials engineers, hydrogen specialists, and naval architects to create a new class of maritime hydrogen storage system.
The work directly supports the UK’s Clean Maritime Plan and wider net zero ambitions by enabling viable hydrogen-powered operations in critical vessel types such as crew transfer vessels (CTVs), one of the fastest-growing specialized vessel classes in the world due to rapidly expanding renewable energy demand.
Challenge
For vessels like CTVs – used to service offshore wind farms – storing enough hydrogen to support a full working day remains a constraint. A typical shift might require 1,500kg of hydrogen, which today’s storage systems would struggle to accommodate without adding bulk or compromising vessel stability.
Conventional high-pressure tanks are often too large and too heavy for these compact, fast-moving vessels. What’s needed is a lightweight, high-capacity system that works at safer pressures and within the physical limits of real maritime operations.
Approach
Working with Australian deep tech SME Rux Energy, NCC has developed a storage system that combines two key technologies:
- Metal-organic framework (MOF) materials - developed by Rux Energy, these advanced nanostructures act like molecular sponges, physically adsorbing 3x more hydrogen per unit volume than conventional systems without any chemical changes to the hydrogen in the tank.
- Cryogenic composite tanks - engineered by NCC, the tanks operate as low as ~40 Kelvin and are designed to handle the thermal and mechanical stresses associated with cryogenic conditions and MOF integration, designed for a rugged marine environment.
A key challenge in hydrogen composite systems is managing thermal expansion and contraction between dissimilar materials, which can lead to micro-cracking. At cryogenic temperatures, these cracks can significantly increase hydrogen permeation, compromising safety and performance. NCC is actively researching cryogenic composite solutions to better understand and mitigate these effects.
Marcus Walls-Bruck, Chief Engineer for Hydrogen at NCC, HVM Catapult and the Hydrogen Innovation Initiative said:
“Maritime hydrogen storage is a complex systems challenge. It demands cross-sector input—from propulsion to naval architecture to materials and gas handling. That’s what HyZEM enables: translating early-stage technology into practical engineering.”
Results
HyZEM has delivered the world’s first Type-V (linerless) MOF-enhanced hydrogen storage prototype vessel:
- 30-litre composite cryogenic tank operating at 20 bar and ~40K
- Early results match expectations of 3x (tripled) hydrogen storage density compared to non-MOF tank at 40 K 20 bar and 7x hydrogen storage density compared to non-MOF tank at 80 K 20 bar
- Lower pressure operation, supporting inherent safety, delivering improved integration optionality for vessel design.
Dr Jehan Kanga, Founder & CEO Rux Energy, and HyZEM Project Joint Leader said:
“These world’s first results show the strategic value of international collaboration and acceleration through co-operation, catapulting two breakthrough hydrogen technologies onto the world stage, together delivering the safety enhancements, and mass, space, energy and cost efficiencies required by our maritime clients.”
Impact
The HyZEM system enables practical, safer, lower cost and more efficient hydrogen storage for smaller vessels - supporting decarbonisation in one of the UK’s hardest-to-abate transport sectors.
The technology contributes directly to:
- Delivering the UK’s Net Zero Maritime Strategy
- Supporting hydrogen-ready infrastructure development at ports
- Accelerating decarbonisation of offshore wind support operations
- Strengthening UK innovation capability in cryogenic hydrogen systems
- Enabling future transfer to other sectors - rail, aviation, and logistics
As the UK scales up offshore wind capacity and hydrogen production, storage remains a critical missing link. HyZEM helps to close that gap - turning lab-scale materials science into engineering systems that work in a marine environment.
Andy Page, Managing Director of Chartwell Marine said:
“This project was hugely informative for our team. Working with Rux Energy and NCC, we have gained a unique insight into the engineering of hydrogen systems, and the impact they have on our vessel. RUX and NCC have identified engineering methods to substantially reduce the weight and volume of tankage, thus improving the engineering arrangement aboard the vessel.”
Next steps
NCC and Rux Energy are continuing the collaboration to optimise the design for gravimetric efficiency. That is maximising the amount of hydrogen stored relative to the total system mass, aiming to build a full-scale 1250L prototype to demonstrate the system’s suitability for real-world deployment on commercial CTVs. Longer term, this technology could play a wider role across the hydrogen economy, where high-density, lightweight storage remains one of the biggest technical bottlenecks to scale.
Tags
Project HyZEM Australia led by Rux Energy acknowledges the generous support of the Australian Commonwealth Department of Climate Change Energy Environment & Water under the Australia-UK Renewable Hydrogen Innovation Partnerships Program.
Project HyZEM UK led by Steamology with NCC support, acknowledges the generous support of Innovate UK and the Department for Business & Trade under the UK-Australia Renewable Hydrogen Innovation Partnerships Program.