Recent discussions in the maritime transport industry suggest that ammonia-powered vessels could become economically viable by 2026, provided certain measures, including subsidies for dual-fuel ship construction projects, are adopted. A recent report by the World Maritime Forum indicates that the cost differential between zero-emission ammonia-powered vessels and those using conventional fuels could be established before 2030. However, the report also notes that ammonia-powered gas carriers could be between 50% and 130% more expensive than their conventional counterparts.
Despite these financial concerns, projects related to ammonia as a marine fuel are progressing rapidly. Manufacturers of marine engines are developing models compatible with ammonia, but the cost of ships and associated operations remains a major concern for shipowners.
Specifically, DNV is designing an ammonia-powered gas carrier, and the Italian group Grimaldi Lines plans to expand its fleet in 2026 with two new vessels for transporting electric vehicles, each with a capacity of 9,000 CEU (car equivalent units). These ships have received RINA’s Ammonia Ready class certification, indicating they can be converted to use ammonia as an alternative fuel in the future. Additionally, Yara Clean Ammonia, NorthSea Container Line, and Yara International have announced a partnership to build the world’s first container ship using pure ammonia as fuel. Named Yara Eyde, this vessel will operate between Norway and Germany from 2026, complementing the Yara Birkeland, the world’s first autonomous electric container ship.
Viability of Ammonia-Powered Vessels by 2026
Moreover, shipping giant Maersk has also committed to ammonia as one of its alternative fuels alongside methanol, signing a contract to build four dual-fuel ammonia vessels of 93,000 cubic meters, with deliveries starting in 2026. Japanese container company Ocean Network Express (ONE) is also initiating orders for new ammonia-powered ships after receiving an “Approval in Principle (AiP)” from SSCC for constructing a dual-fuel ammonia vessel, following its twelve dual-fuel methanol vessels already on order.
Blue Fuels: Bridging the Gap to Green
Currently, much discussion revolves around green, grey, and blue fuels. While green and grey fuels are somewhat well-understood, blue fuels are less familiar. Most alternative marine fuels like methanol, ammonia, and hydrogen are currently derived from fossil natural gas, meaning they are not inherently green or clean. However, the CO2 intensity of producing these fuels can be drastically reduced by implementing technological solutions like carbon capture and storage (CCS), producing what are known as “blue fuels.”
The transitional use of blue fuels is crucial for gaining time to increase the supply of green fuels (and biofuels), ensuring a stable supply chain. Fully renewable fuels are not yet available in sufficient volumes to meet the demand for new orders. For instance, MAN Energy Solutions currently has over 100 two-stroke dual-fuel methanol engines on order.
Increasing the production of existing fuels using carbon capture and storage to produce blue ammonia, methanol, and hydrogen is another critical step toward achieving decarbonization goals.
LNG: A Transitional Fuel
Today, 99% of the world’s merchant fleet is still powered by diesel engines running on marine gas oil. The search for alternative solutions to decarbonize the oceans has sparked a race to find clean alternative fuels. Three prominent contenders are LNG (liquefied natural gas), methanol, and ammonia. LNG, while still emitting CO2, is considered a transitional fuel rather than a long-term solution. However, current ship orders reflect that all three fuels will soon have their place.
Recently, under the umbrella of COP28, 198 countries, including oil-producing nations for the first time, signed an agreement to develop clean technologies and phase out fossil fuels in a fair and orderly manner, aiming for “net zero emissions” by 2050. In response, the maritime industry is ramping up orders for new ships, prominently featuring those powered by LNG, methanol (dual fuel-methanol), and ammonia (dual fuel-ammonia).
Methanol: Gaining Traction
Methanol has gained popularity in the maritime industry recently. The Chinese maritime market, for instance, is showing interest in methanol, as many existing ships could use it with minor engine modifications. China, already a leader in renewable energy production (necessary for producing green liquid methanol), could further its decarbonization ambitions through this shift.
Since 2016, chemical tankers burning methanol have been operational, using a segregated portion of their cargo as fuel, similar to gas carriers. The number of methanol-powered ships, currently around 30, is expected to rise to 200 in the coming years, based on existing orders.
The Challenge of Ammonia
Ammonia engines, despite the additional challenge of toxicity, are about a decade behind methanol engines in development. While some operational ships are equipped with ammonia engines, a significant increase in ammonia-powered vessels is expected next year. Maersk has confirmed its commitment to ammonia as a transitional green fuel, signing a contract for 10 ships with deliveries starting in 2026.
New ships with dual-fuel engines will continue burning marine gas oil alongside new fuels. Marine gas oil will remain secondary but necessary for these engines. Importantly, the production of ammonia and methanol must be green and clean. Producing methanol via LNG, for example, would not meet IMO’s decarbonization criteria. E-fuels or biofuels must be produced.
All new fuels will increase maritime transport costs. For instance, Maersk’s large container ships will need to sacrifice space equivalent to 700 TEU if using methanol and 500 TEU for ammonia. Moreover, fishing vessels, due to weight and space constraints affecting stability, are currently not viable for these solutions to achieve decarbonization.
