Trend watch: Ammonia as shipping fuel & hydrogen carrier in 2026 — signals, winners, and red flags

The International Maritime Organization's revised GHG strategy, adopted in July 2023, commits the global shipping industry to net-zero emissions by or around 2050, with a 20% reduction by 2030 and a 70% reduction by 2040 compared to 2008 levels. Ammonia has emerged as the leading candidate fuel to meet these targets: by early 2026, over 200 vessels with ammonia-ready or ammonia-capable engines were on order globally, representing $18 billion in shipbuilding contracts, according to Clarksons Research. Yet not a single commercial vessel is operating on ammonia today, and the green ammonia supply chain required to deliver genuine emissions reductions remains years from scale. This gap between order books and operational reality defines the central tension for anyone evaluating ammonia as a maritime fuel or hydrogen carrier in 2026.

Why It Matters

Shipping is responsible for approximately 3% of global greenhouse gas emissions, roughly 1 billion tonnes of CO2 equivalent annually, making it one of the hardest-to-abate sectors in the global economy. The industry's reliance on heavy fuel oil (HFO) and marine gas oil (MGO) reflects the extreme energy density requirements of transoceanic voyages: a large container ship consumes 150 to 300 tonnes of fuel per day, and no battery technology can match the volumetric energy density of liquid hydrocarbons for voyages spanning 10,000 nautical miles or more.

Ammonia (NH3) offers a pathway through this constraint. While its volumetric energy density is roughly 50% that of HFO, ammonia contains no carbon atoms, meaning its combustion produces no direct CO2 emissions. When produced using renewable electricity (green ammonia) or natural gas with carbon capture (blue ammonia), the full lifecycle emissions reduction reaches 80 to 95% compared to conventional marine fuels. The global ammonia production infrastructure already handles approximately 185 million tonnes per year, primarily for fertilizer manufacturing, providing an existing industrial base that other alternative fuels (hydrogen, methanol, synthetic fuels) lack.

The regulatory signal driving adoption is the IMO's basket of mid-term measures under discussion, including a global fuel standard (GFS) that would set lifecycle greenhouse gas intensity limits for marine fuels, and an economic mechanism (likely a levy or emissions trading system) that would price marine carbon emissions. The European Union's FuelEU Maritime regulation, effective from January 2025, already mandates a 2% reduction in the greenhouse gas intensity of onboard energy used by ships calling at EU ports, escalating to 80% by 2050. These regulatory ratchets create progressively stronger economic incentives to shift away from fossil fuels, with ammonia positioned as the primary zero-carbon option at scale.

The hydrogen carrier dimension adds strategic importance beyond shipping. Ammonia is 1.7 times denser in hydrogen content per unit volume than liquid hydrogen itself, and can be transported at moderate pressure (10 bar) or refrigerated to minus 33 degrees Celsius, far less demanding than liquid hydrogen's minus 253 degrees Celsius. This makes ammonia the most cost-effective vector for transporting hydrogen energy across intercontinental distances. Japan's Green Innovation Fund has allocated 300 billion yen ($2 billion) specifically to establish ammonia supply chains for both power generation and industrial use, with imports planned from Australia, Saudi Arabia, and the UAE.

Key Concepts

Green Ammonia is produced by electrolyzing water using renewable electricity to generate hydrogen, then combining that hydrogen with atmospheric nitrogen via the Haber-Bosch process or emerging electrochemical synthesis methods. The lifecycle carbon intensity of green ammonia is 0.3 to 0.5 tonnes CO2e per tonne of ammonia, compared to 1.6 to 2.4 tonnes CO2e per tonne for conventional (grey) ammonia produced from unabated natural gas. Green ammonia production costs in 2025 range from $600 to $1,000 per tonne, compared to $250 to $400 for grey ammonia, though cost projections for 2030 converge to $400 to $600 as electrolyzer costs decline and renewable electricity becomes cheaper.

Two-Stroke Ammonia Engines represent the primary technology pathway for large oceangoing vessels. MAN Energy Solutions and WinGD (Winterthur Gas and Diesel) are developing two-stroke ammonia engines capable of powering the largest container ships, bulk carriers, and tankers. MAN ES announced in 2024 that its ME-LGIP engine (a dual-fuel design burning ammonia with a pilot injection of traditional fuel for ignition) would be commercially available from 2025 for newbuild vessels. Engine thermal efficiency targets of 45 to 50% match conventional diesel performance. The key technical challenges remain NOx and N2O emissions management (nitrous oxide is 273 times more potent as a greenhouse gas than CO2), combustion stability at variable loads, and corrosion resistance in fuel supply systems.

Ammonia Bunkering Infrastructure refers to the port-based fueling facilities needed to supply ammonia to vessels. Unlike LNG bunkering (which has developed over 15 years to reach approximately 200 ports globally), ammonia bunkering infrastructure is nascent. The Port of Rotterdam, Port of Singapore, Port of Fujairah, and several Japanese ports have announced ammonia bunkering feasibility studies or pilot projects, but no commercial-scale ammonia bunkering facility is operational as of early 2026. Safety requirements for ammonia handling (the substance is toxic at concentrations above 300 ppm) add complexity and cost compared to conventional fuels.

Ammonia Cracking is the reverse process of converting ammonia back into hydrogen and nitrogen at the point of use. For hydrogen carrier applications, cracking efficiency (currently 70 to 85% with commercial catalytic crackers) determines the round-trip energy penalty of using ammonia as a transport vector. Research at institutions including CSIRO (Australia) and Korea Institute of Energy Research has demonstrated cracking efficiencies above 90% with novel ruthenium-based catalysts, though commercial-scale validation remains ongoing.

Ammonia as Shipping Fuel KPIs: 2026 Benchmark Ranges

Metric	Current State	2030 Target	Industry Goal (2040)
Green Ammonia Production Cost ($/tonne)	$600-1,000	$400-600	$250-350
Ammonia Engine Availability	Pre-commercial	Series production	Standard option
Bunkering Ports with Ammonia Capability	0 commercial	10-20	50+
Vessels on Order (ammonia-capable)	200+	500+	2,000+
N2O Slip (g/kWh)	Under testing	<0.02	<0.005
Ammonia Fuel Cost vs. HFO	3-4x premium	2-2.5x premium	1.2-1.5x premium
Lifecycle GHG Reduction (green ammonia vs. HFO)	80-90%	85-95%	>95%

What's Working

MAN Energy Solutions Engine Development Program

MAN Energy Solutions, the dominant manufacturer of large two-stroke marine engines (powering roughly half of global shipping tonnage), has committed fully to ammonia propulsion. The company's ME-LGIP ammonia engine completed extensive testing at its Copenhagen Research Centre throughout 2024 and 2025, demonstrating stable combustion across 25 to 100% load ranges with NOx emissions within IMO Tier III limits using selective catalytic reduction. MAN ES secured orders for ammonia-capable engines from over 30 shipowners by early 2026, including Mitsui O.S.K. Lines, NYK Line, and Eastern Pacific Shipping. The company's "ammonia-ready" newbuild concept allows vessels to operate on conventional fuel during the transition period while being designed for conversion to ammonia within 2 to 3 years once fuel supply materializes. This hedged approach has proven commercially effective, as shipowners avoid stranded asset risk while reserving optionality.

NEOM Green Hydrogen and Ammonia Project

The NEOM Green Hydrogen Company (a joint venture of ACWA Power, Air Products, and NEOM) is constructing the world's largest green hydrogen and ammonia production facility in Saudi Arabia. The project will use 4 GW of dedicated wind and solar capacity to produce 600 tonnes per day of green hydrogen, converted to 1.2 million tonnes per year of green ammonia for export. Construction is well advanced with first production targeted for 2026. Air Products holds a 30-year exclusive offtake agreement to distribute the ammonia globally. The project demonstrates that green ammonia can be produced at scale in regions with exceptional renewable resources (capacity factors exceeding 55% for combined wind and solar), and the $8.4 billion investment signals confidence from major industrial players. NEOM's cost projections of $400 to $500 per tonne of green ammonia by 2030 would make it competitive with blue ammonia on a lifecycle basis.

Japanese Government Strategic Commitment

Japan has positioned ammonia as a cornerstone of its energy security and decarbonization strategy, driven by the dual imperative of reducing fossil fuel import dependence and decarbonizing its industrial base. The Ministry of Economy, Trade, and Industry (METI) published the first national Ammonia Fuel Strategy in 2024, targeting 3 million tonnes per year of ammonia consumption for power generation by 2030 and 30 million tonnes by 2050. JERA, Japan's largest power generator, commenced 20% ammonia co-firing at its 4.1 GW Hekinan coal plant in 2024, with plans to scale to 50% by 2028 and potentially 100% by the early 2030s. Japan's approach de-risks the upstream supply chain by creating anchor demand that attracts investment in production facilities across Australia, the Middle East, and Southeast Asia.

What's Not Working

Green Ammonia Supply Shortage

Despite ambitious project announcements, the current global supply of green ammonia is negligible. The International Energy Agency estimated total green ammonia production in 2025 at fewer than 100,000 tonnes, less than 0.05% of total ammonia production. The majority of announced green ammonia projects remain at feasibility or front-end engineering design (FEED) stages, with final investment decisions delayed by electrolyzer delivery bottlenecks, power purchase agreement complexity, and uncertainty about offtake commitments. Without a rapid scale-up in green ammonia supply, ships equipped with ammonia engines risk being fueled by grey or blue ammonia with substantially higher lifecycle emissions, undermining the environmental rationale for the fuel switch.

Toxicity and Safety Concerns

Ammonia is acutely toxic. Exposure to concentrations above 300 ppm causes severe respiratory damage, and concentrations above 2,500 ppm are rapidly fatal. While the fertilizer industry has decades of experience handling ammonia safely in controlled industrial settings, maritime operations introduce unique challenges: confined spaces on vessels, exposure to weather and wave forces during bunkering, proximity to populated port areas, and the need for crew training and emergency response capability. The Maritime and Port Authority of Singapore published provisional ammonia bunkering safety guidelines in 2025 that impose standoff distances, continuous atmospheric monitoring, and emergency ventilation requirements that significantly complicate port operations. Insurers including the International Group of P&I Clubs have flagged ammonia toxicity as a factor in liability assessments for early adopters.

N2O Slip and Incomplete Combustion

Nitrous oxide emissions from ammonia combustion represent a critical environmental risk. N2O has a global warming potential 273 times that of CO2 over a 100-year period, meaning even small quantities of N2O slip can negate the greenhouse gas benefits of switching from fossil fuels. Early engine testing revealed N2O formation rates that, if unmanaged, could make ammonia-fueled ships worse for the climate than conventional diesel in a 20-year warming analysis. Engine manufacturers are developing catalytic aftertreatment systems to reduce N2O to harmless nitrogen gas, but commercial-scale validation at sea conditions (vibration, variable loads, salt spray) remains incomplete. The IMO has not yet established N2O emission limits for ammonia-fueled vessels, creating regulatory uncertainty about future compliance costs.

Bunkering Infrastructure Chicken-and-Egg Problem

No shipowner will commit to ammonia propulsion without assurance of fuel availability at ports along key trading routes, and no port authority will invest in ammonia bunkering infrastructure without firm demand from shipping lines. This coordination failure is the primary barrier to adoption. The Global Maritime Forum's 2025 survey of 50 major ports found that only 12 had initiated formal feasibility studies for ammonia bunkering, and none had committed capital to construction. Breaking this deadlock requires coordinated investment by fuel suppliers, port authorities, and shipping lines, likely supported by public financing or long-term supply contracts that reduce risk for each party.

Key Players

Established Leaders

MAN Energy Solutions (Germany/Denmark) dominates large two-stroke engine manufacturing and leads ammonia engine development. Their ME-LGIP platform is the most advanced ammonia-capable engine program globally.

ACWA Power (Saudi Arabia) is developing multiple green hydrogen and ammonia projects across the Middle East and North Africa, including the flagship NEOM facility. The company's expertise in large-scale renewable energy and desalination positions it uniquely for green ammonia production.

JERA (Japan) is the world's largest buyer of LNG and is pioneering ammonia co-firing in coal power plants, creating anchor demand for ammonia supply chains across Asia-Pacific.

Yara International (Norway) is the world's largest ammonia producer and is investing in green ammonia production, including the Yara Clean Ammonia joint venture targeting marine fuel and hydrogen carrier markets.

Emerging Startups

Amogy (USA) developed a compact ammonia cracking and fuel cell system that converts ammonia to electricity onboard vessels without combustion, eliminating NOx and N2O emissions entirely. The company demonstrated its technology on a tugboat in 2023 and is targeting commercial vessels by 2027.

Fortescue Future Industries (Australia) is building the Gibson Island green ammonia plant in Queensland, targeting production of green ammonia for both domestic use and export to Asian markets. The project leverages Fortescue's mining infrastructure and renewable energy assets.

Starfire Energy (USA) developed a modular, distributed ammonia synthesis technology based on non-thermal plasma catalysis, enabling ammonia production at smaller scales closer to the point of use, potentially reducing transport costs.

Key Investors and Funders

Japan Green Innovation Fund allocated 300 billion yen ($2 billion) for ammonia supply chain development, the largest single government commitment to ammonia as an energy carrier.

Saudi Arabia's Public Investment Fund backs NEOM and ACWA Power investments, channeling sovereign wealth into green ammonia production infrastructure.

AP Moller-Maersk invested in ammonia fuel development through its green methanol fleet program and maintains ammonia as a candidate fuel for future vessel classes, with significant R&D expenditure on dual-fuel flexibility.

Red Flags to Monitor

The first red flag is lifecycle accounting integrity. If ammonia-fueled vessels operate primarily on grey ammonia (produced from unabated natural gas), the net climate benefit is marginal or negative after accounting for upstream methane leakage and N2O combustion emissions. Practitioners should demand well-to-wake lifecycle analyses for any ammonia supply contract, verified against ISO 14040/14044 standards, and reject claims based solely on tank-to-wake (zero CO2) accounting.

The second red flag is technology lock-in risk. Ammonia engine orders placed in 2025 to 2026 are based on first-generation designs that may not meet eventual IMO N2O limits. Shipowners should negotiate contractual provisions for engine upgrades and aftertreatment retrofits, and model the cost of compliance with regulations that do not yet exist.

The third red flag is green premium persistence. If the cost gap between green and grey ammonia does not narrow substantially by 2030, the industry faces pressure to weaken lifecycle requirements or extend timelines, eroding the climate rationale for the transition. Monitor electrolyzer cost trajectories and renewable electricity PPAs in key production regions (Chile, Australia, Middle East, North Africa) as leading indicators.

Action Checklist

• Evaluate ammonia alongside methanol, LNG, and battery-electric propulsion for your vessel types, route profiles, and decarbonization timeline
• Assess green ammonia supply contract availability along your primary trading routes before committing to ammonia-capable newbuilds
• Require well-to-wake lifecycle emissions certification for any ammonia fuel supply agreement
• Negotiate ammonia-ready vessel designs that can operate on conventional fuel during the transition period
• Monitor IMO mid-term measures negotiations, particularly the global fuel standard and carbon levy proposals, for impact on fuel economics
• Engage port authorities along key routes to understand ammonia bunkering infrastructure timelines and safety requirements
• Build crew training and safety management systems for ammonia handling before vessel delivery
• Model total cost of ownership across 25-year vessel life under multiple fuel price and regulatory scenarios

FAQ

Q: When will ammonia be commercially available as a marine fuel? A: First commercial ammonia-fueled vessels are expected to enter service in 2027 to 2028, using dual-fuel engines from MAN Energy Solutions or WinGD. However, widespread availability depends on bunkering infrastructure development, with only 10 to 20 ports likely to offer ammonia bunkering by 2030. Full commercial viability, meaning competitive cost and broad port access, is unlikely before 2032 to 2035.

Q: How does ammonia compare to methanol as an alternative marine fuel? A: Methanol is further along commercially, with Maersk operating 18 methanol-fueled container ships by 2026. Methanol benefits from simpler handling (low toxicity, liquid at ambient conditions) and existing port infrastructure adaptability. However, green methanol requires biogenic CO2 or direct air capture, constraining supply scalability. Ammonia has superior long-term supply potential because production requires only renewable electricity, water, and air. The two fuels likely coexist, with methanol preferred for container and short-sea shipping and ammonia for bulk, tanker, and deep-sea routes.

Q: What is the cost premium for ammonia-fueled shipping today? A: Using green ammonia at current prices ($600 to $1,000 per tonne) results in fuel costs 3 to 4 times higher than conventional HFO ($400 to $500 per tonne in energy-equivalent terms). Ammonia-capable engines add approximately 10 to 15% to newbuild vessel costs. Total cost of ownership premiums of 30 to 50% over conventional vessels are typical in 2026 projections. These premiums are expected to narrow as green ammonia production scales, carbon pricing increases, and engine technology matures, with breakeven projected around 2033 to 2037 depending on carbon price trajectory.

Q: What safety measures are required for ammonia as a marine fuel? A: Safety requirements include gas-tight fuel storage and supply systems, continuous atmospheric ammonia monitoring throughout the vessel, forced ventilation in machinery spaces, crew certification in ammonia handling and emergency response, and double-walled piping for fuel transfer. Bunkering requires enclosed transfer systems, vapor recovery, emergency shutdown capabilities, and exclusion zones around transfer points. The IMO's Interim Guidelines for Ships Using Ammonia as Fuel (expected in 2026) will establish mandatory requirements, but early adopters are designing to more conservative standards based on fertilizer industry best practices.

Q: Is blue ammonia a viable bridge fuel while green ammonia scales? A: Blue ammonia (produced from natural gas with carbon capture and storage) can serve as a transitional supply source, with lifecycle emissions 50 to 70% lower than grey ammonia depending on capture rates and upstream methane leakage. Saudi Aramco and SABIC shipped the first blue ammonia cargo to Japan in 2020, and several additional blue ammonia projects are in development. However, blue ammonia's climate credibility depends on achieving carbon capture rates above 90% and controlling methane leakage below 0.5% across the natural gas supply chain, standards that many existing gas production systems do not currently meet. Buyers should require independent verification of capture rates and upstream emissions.

Sources

• International Maritime Organization. (2023). 2023 IMO Strategy on Reduction of GHG Emissions from Ships. London: IMO.
• Clarksons Research. (2026). Alternative Fuel Vessel Orderbook: Q1 2026 Update. London: Clarksons.
• International Energy Agency. (2025). Ammonia Technology Roadmap: Towards More Sustainable Nitrogen Fertiliser Production. Paris: IEA.
• MAN Energy Solutions. (2025). ME-LGIP Ammonia Engine: Technical Documentation and Testing Results. Copenhagen: MAN ES.
• Global Maritime Forum. (2025). Annual Progress Report on the Transition to Zero-Emission Shipping. Copenhagen: GMF.
• Ministry of Economy, Trade and Industry, Japan. (2024). Ammonia Fuel Strategy. Tokyo: METI.
• IRENA and Ammonia Energy Association. (2025). Innovation Outlook: Renewable Ammonia. Abu Dhabi: IRENA.