Hydrogen-powered Ships: Where We Are, Why it Matters, and How to Scale the Clean-fuel Voyage
Hydrogen for shipping is no longer only a research topic. Governments, yards and technology providers have moved from demonstration projects to early commercial pilots — especially for ferries, harbour vessels and short-sea operators.
All this while the industry debates the most scalable route - liquid/pressurised hydrogen, hydrogen fuel cells, hydrogen internal combustion engines, or hydrogen carriers like ammonia/methanol.
At the system level, low-emissions hydrogen production is growing but still tiny relative to overall hydrogen supply, and most hydrogen today is produced from fossil fuels.
Several technical and regulatory milestones arrived recently: fuel-cell safety and design codes have matured, white papers from classification and advisory bodies give roadmaps for safe adoption, and comparative studies weigh hydrogen against other zero-carbon fuel candidates (ammonia, methanol, batteries).
These advances make early adoption feasible — but not yet cheap or widespread.
How hydrogen powers ships — the technical options
Direct hydrogen in fuel cells (H₂ → electricity):
Proton exchange membrane (PEM) or other fuel cells convert hydrogen to electricity with high electrical efficiency and near-zero local pollutants (no SOx, PM; very low NOx). This is an excellent fit for vessels that need quiet, low-emission power — e.g., ferries, tugs, port vessels. Fuel cells require high-purity hydrogen and careful onboard storage and safety systems.
Hydrogen internal combustion engines (H2ICE):
Modified internal combustion engines can run on hydrogen. They are simpler to integrate into existing mechanical drivetrains but generally offer lower efficiency than fuel cells and present combustion-related NOx control challenges.
Hydrogen carriers (ammonia, methanol, LOHCs):
For long-range deep-sea shipping, ammonia or methanol — produced from green hydrogen — are attractive because they are easier to store and bunker than cryogenic/liquefied hydrogen. Engines and fuel-cell technologies that use ammonia or methanol are advancing rapidly and may be the most realistic near-term pathway for large ocean-going vessels.
Why hydrogen is attractive for shipping
Near-zero local emissions: Fuel cells emit only water vapour at the point of use (no CO₂ if hydrogen is green), eliminating SOx, PM and greatly reducing NOx compared with fossil fuels. This helps ports and coastal communities meet air-quality goals.
High efficiency for electric drivetrains: Combined hydrogen fuel cell + battery hybrids can offer high system efficiency for variable loads found in ferry and harbor operations.
Flexibility of use: Hydrogen (or hydrogen-derived fuels) can power both electric and combustion systems, and acts as an energy vector that links renewable electricity to transport decarbonisation.
Main challenges — why hydrogen isn’t yet widespread
Energy density and storage complexity:
Hydrogen (especially gaseous) has low volumetric energy density compared with conventional fuels and requires high-pressure tanks or cryogenic storage, consuming space and weight on board. This limits immediate applicability to short-haul vessels or those designed for hydrogen storage.
Cost and scale of green hydrogen:
“Green” hydrogen (produced from renewables) remains expensive and limited in supply; low-emissions hydrogen grew in 2024–25 but still represents under 1% of global hydrogen production, per tracking reports. Without abundant cheap green hydrogen, lifecycle emissions gains are limited.
Bunkering infrastructure:
Ports need new facilities for storage, handling and safety of hydrogen or hydrogen-derived fuels. Bunkering systems, standards and port investment are lagging — a classic “chicken-and-egg” barrier between fuel supply and ship demand.
Safety and regulation:
Hydrogen’s flammability and the cryogenic/pressurised technologies require new safety codes, training, and emergency procedures. While codes are emerging, harmonised global regulations are still catching up.
Economics for deep-sea shipping:
For large ocean-going vessels, fuel cost per tonne-mile remains the decisive factor. Until green hydrogen (or green ammonia/methanol) reaches price parity with conventional marine fuels — or carbon pricing/regulatory incentives shift economics — uptake will be limited.
Where hydrogen is most promising (the near term)
Short-sea and ferry services: predictable routes, return-to-base bunkering and smaller storage needs make ferries and commuter vessels prime early adopters.
Port, harbour and auxiliary vessels: tugs, pilot boats and harbour crafts operate in emission-sensitive zones and can benefit from fuel cells’ air-quality advantages.
Hybrid applications and pilot projects: retrofits with fuel cells + batteries for hybrid propulsion reduce fuel use and emissions in a staged way.
For long-range shipping, hydrogen-derived fuels (green ammonia and e-methanol) currently present a more practical bridging solution while hydrogen production and cryogenic logistics scale up.
The future — scaling to 2030 and beyond
A plausible pathway to wide hydrogen use in shipping looks like this:
2025–2030 — pilots to early commercial: rapid expansion of ferry and harbour vessel pilots; ports invest in dedicated bunkering hubs at major short-sea nodes; regulatory bodies finalise safety codes.
2030–2040 — scaling supply chains: green hydrogen electrolyser capacity grows; regional hydrogen corridors and dedicated shipping fuel-supply chains (including ammonia terminals) expand; cost curves fall with industrial scaling.
2040+ — mature market for long-range deep-sea fuels: if low-cost green hydrogen or green ammonia becomes available at scale and bunkering networks are in place, broader adoption by ocean-going vessels becomes commercially viable. Policy measures (carbon pricing, fuel standards) will drastically accelerate this phase.
A practical, high-impact way forward (policy, industry, ports)
Prioritise early deployments in short-sea corridors and port fleets where emissions and air-quality benefits are immediate — build demonstrators and replicate successful designs.
Invest in port bunkering hubs and standards now — ports should develop hydrogen/ammonia bunkering roadmaps, co-fund infrastructure and coordinate with local industry.
Scale green hydrogen production and lower costs: coordinated policy (renewable build-out, electrolyser incentives, power contracting) is essential to bring down levelised cost of green hydrogen.
Harmonise safety and class rules quickly: adoption depends on trusted codes and crew training; classification societies and regulators must finalise interoperable standards.
Use transitional fuels strategically: where direct hydrogen is unfeasible, develop infrastructure for hydrogen-derived fuels (green ammonia/methanol) alongside R&D for direct hydrogen systems.
De-risk investment with blended finance and demand signals: public grants, offtake agreements and carbon pricing can close the commercial gap for first movers.
Bottom line
Hydrogen offers a compelling low-emission pathway for parts of the maritime sector today — especially ferries, harbour vessels and hybrid retrofits — and a credible route to decarbonise heavier shipping via hydrogen-derived fuels in the medium term.
The technology is proven at demonstrator scale, safety and design codes are emerging, and the policy framework is beginning to align.
The real challenge is upstream: scaling affordable green hydrogen, building bunkering infrastructure, and aligning incentives so that shipowners, ports and fuel producers can invest with confidence. If policy, industry and finance act together now, hydrogen can become a major pillar of a zero-carbon maritime future.
