Alternative Marine Fuels in 2026: LNG, Methanol, Ammonia and Biofuel

The regulatory backdrop

The IMO's Net-Zero Framework — which proposes a carbon levy on ships above 5,000 gross tonnes alongside intermediate targets toward net-zero around 2050 — was expected to give low-carbon fuels a decisive cost advantage. Its adoption was postponed at the Marine Environment Protection Committee's extraordinary session in October 2025, and that delay has injected near-term uncertainty and tempered the momentum behind alternative fuels. Regional rules have not waited: EU ETS and FuelEU Maritime continue to push vessels calling Europe regardless of the IMO timetable.

LNG: the mature option

LNG is the most established alternative, with a real bunkering network and a meaningful and growing share of the fleet able to use it. It cuts sulphur oxides and reduces carbon dioxide versus heavy fuel oil, but it is still a fossil fuel, and methane slip — unburned methane, a far more potent greenhouse gas than CO₂ — undercuts its climate case. It is best understood as a transition fuel. See our LNG page for grade detail.

Methanol: momentum, with a catch

Methanol has attracted a wave of newbuild and dual-fuel orders from major liner operators, helped by the fact that it is liquid at ambient temperature and relatively straightforward to handle and bunker. The catch is supply: the overwhelming majority of methanol produced today is fossil-derived, and genuinely low-carbon green or e-methanol remains costly and scarce. The vessels are arriving faster than the clean fuel to run them. See the methanol page.

Ammonia: promising, but early

Ammonia carries no carbon at the point of combustion, which makes it a strong long-term candidate for deep-sea shipping. But it is at an early stage: toxicity and handling, lower energy density, and limited engine availability all need to be resolved. Cost modelling generally sees ammonia becoming competitive only from the late 2030s, often paired with LNG in dual-fuel designs as a stepping stone.

Biofuel: the pragmatic near-term lever

For most of the existing fleet, biofuel blends such as B24 and B30 are the most practical way to cut emissions now. They are largely drop-in — usable in existing engines and bunkering infrastructure with little or no capex — and demand is being pulled forward by FuelEU Maritime. The constraints are feedstock availability, sustainability certification and cost rather than technology.

What it means for operators now

Through the late 2020s, the realistic picture is conventional fuels supplemented by biofuel blends for the bulk of the fleet, LNG for owners with dual-fuel tonnage, and methanol or ammonia as newbuild bets for those positioning further ahead. The decisive question is shifting from fuel price alone to total compliance cost — fuel plus carbon — on the trade lanes a vessel actually serves.