With maritime shipping responsible for around 3 per cent of global emissions and new measures from the International Maritime Organization, the European Commission and FuelEU Maritime, the industry is urged to rethink its most fundamental input – fuel.
Against this backdrop, Lloyd’s Register (LR) has released the latest instalment in its award-winning Fuel for Thought series, turning its attention to hydrogen and its potential role in shipping’s energy transition. Published in January 2026, Fuel for Thought: Hydrogen offers a clear-eyed assessment of both the opportunities and the obstacles facing one of the most talked-about fuels in the decarbonisation debate – hydrogen.
LR’s broader Fuel for Thought program examines alternative fuel pathways; including, methanol, ammonia, biofuels and electrification. The series reflects a growing recognition that no single fuel will provide a universal solution. Instead, shipping’s future is likely to be shaped by a mix of technologies and use cases, constrained by cost, infrastructure and operational realities.
A sector searching for scalable solutions
Alternative fuels have moved rapidly from niche concept to strategic necessity in maritime transport. Environmental regulation is tightening, but so too is scrutiny from investors and customers who are increasingly demanding credible decarbonisation pathways. At the same time, shipowners are urged to balance emissions reduction with operational realities such as vessel range, payload capacity, safety and fuel availability.
Today’s menu of marine fuel options is broad and still evolving. It includes LNG and LPG as transitional fuels, biofuels that can often be blended with existing marine fuels, and emerging zero or near-zero-emissions options, such as hydrogen, ammonia, methanol and battery-electric systems. Even nuclear propulsion occasionally features in long-term discussions for specific vessel classes.
Each comes with trade-offs. Ammonia, for example, offers high energy density and zero carbon at the point of use, but presents significant toxicity and infrastructure challenges. Biofuels can deliver near-term emissions reductions using existing engines, but face constraints around sustainable feedstock supply. Batteries are well suited to short-sea shipping but remain impractical for long-distance routes.
Hydrogen occupies a unique position in this mix. When produced using renewable electricity and used in fuel cells, green hydrogen can deliver zero tank-to-wake emissions. It is also a critical building block for e-fuels, such as ammonia and methanol, giving it strategic importance beyond its direct use onboard ships.
Hydrogen under the microscope
LR’s new report examines hydrogen from production and supply through to onboard use, highlighting both its promise and the reasons it remains a challenging option for most vessel types.
On the positive side, hydrogen’s climate credentials are compelling. In fuel cell applications, it produces only water as an exhaust product. It is also highly versatile, with potential to serve as a direct fuel, a feedstock for synthetic fuels, or a form of energy storage linked to renewable power systems.
But the physical realities of hydrogen are hard to ignore. Its low volumetric energy density means far larger storage volumes are required compared with conventional marine fuels. In liquid form, hydrogen must be stored at around –253°C, introducing complexity and energy penalties. These factors translate directly into lost cargo space, higher costs and more complicated vessel designs.
Safety is another critical consideration. Hydrogen has a wide flammability range, low-ignition energy and can cause embrittlement in certain materials. Managing these risks requires rigorous engineering standards, specialised systems and enhanced crew training.
LR’s own rules for ships using low-flashpoint fuels, including its hydrogen requirements set out in Appendix LR3, provide a framework for addressing these issues. The guidance covers fuel cells, composite cylinders, liquid hydrogen systems and bunkering arrangements, reflecting the depth of technical change required to support hydrogen at sea.
The missing pieces: Infrastructure and supply
Perhaps the biggest barrier to hydrogen’s wider adoption is not onboard technology, but what happens onshore. Despite growing interest and a wave of national hydrogen strategies, low-emissions hydrogen still accounts for less than 1 per cent of global production, according to the International Energy Agency.
Significant investment is needed across the entire value chain – from production, transport, storage and bunkering. For shipping, the challenge is compounded by the need for reliable, standardised refuelling infrastructure in ports around the world.
Competition for green hydrogen will also be intense. Heavy industry, chemicals, fertilisers, power generation and long-haul transport are all targeting the same limited supply. This makes robust certification schemes and transparent lifecycle assessments essential to ensure that maritime decarbonisation efforts deliver genuine climate benefits.
Under FuelEU Maritime, renewable fuels of non-biological origin (including green hydrogen) benefit from a two-times multiplier until 2033, potentially accelerating early uptake as production scales. But for now, cost remains a major hurdle.
Reflecting this reality, hydrogen-capable vessels still represent less than 0.5 per cent of the global orderbook, despite growing regulatory and industry interest.
Where hydrogen makes sense
While the report is cautious about hydrogen’s near-term role in deep-sea shipping, it identifies clear opportunities in shorter routes and specialist applications. Ferries, tugs and coastal vessels, where regular bunkering cycles reduce storage constraints, are seen as the most viable early adopters.
Fuel cell technologies particularly show promise in these segments, supported by improving cost trajectories and advances in durability. Hybrid configurations and ‘hydrogen-ready’ designs also offer shipowners a way to future-proof assets without committing fully to a single fuel pathway.
Padmini Mellacheruvu, Lead Technical Specialist in Cryogenic and Compressed Fuel Systems at LR, shared that hydrogen has an important role to play, but warned the pathway to scale will be complex.
“Progress will depend on early investment, careful planning and a clear focus on safety,” she said.
“Our latest Fuel for Thought report brings clarity to both the potential of hydrogen and the substantial work still required to enable its safe, scalable and commercially viable use.”
Wider energy transition
The hydrogen report, as part of LR’s wider Fuel for Thought series, aims to provide practical, evidence-based insights into the rapidly evolving alternative fuels landscape. The overarching message is that the shipping transition will not be defined by a single winner, but by a portfolio of solutions tailored to different routes, vessel types and regional conditions.
Dr Maximilian Kuhn, Advisor to Hydrogen Europe and ISO TC 197 liaison to the International Maritime Organization, said hydrogen should be seen as a driver of systemic change rather than a standalone answer.
“Its versatility, scalability and compatibility with renewable energy sources put it in a unique position to address the complex challenges of maritime decarbonisation,” he said.
“Yet the path forward is not without obstacles: infrastructure, regulation, safety and cost remain critical hurdles.”
For Australia, with its vast renewable resources and ambitions to become a clean energy and hydrogen export powerhouse, these developments will be closely watched. While the initial focus has been on land-based industry and exports, the maritime sector will ultimately be both a customer and an enabler of a global hydrogen economy.