For more than a century, the economics of ocean shipping rested on a simple fact: heavy fuel oil was cheap, energy-dense and available in every major port. That assumption is now actively being dismantled. Major container carriers are putting dual-fuel methanol vessels into regular service, ammonia-capable designs are moving from concept to shipyard order books, and the regulatory pressure driving this shift is only getting stronger. For anyone planning ocean transportation logistics over the next decade, the fuel a vessel burns is no longer a background engineering detail — it is becoming a real factor in freight rates, route planning and even which ports a shipper can reliably route cargo through. Understanding the alternative marine fuels landscape is becoming as relevant to a shipper's planning as understanding carrier alliances or vessel schedules, because fuel choice now has a direct bearing on cost and route availability.
Why Shipping Needs a New Fuel at All
International shipping has historically run on heavy fuel oil, a carbon-intensive byproduct of crude refining that is cheap precisely because it has so few other uses. As pressure to decarbonize global trade has intensified — through both voluntary carrier commitments and binding regulation — heavy fuel oil has become a liability rather than a cost advantage. The challenge is that no single replacement fuel offers the same combination of energy density, cost and global availability that heavy fuel oil did, which is why the industry is pursuing several candidate alternative marine fuels in parallel rather than converging quickly on one winner. Shipowners now have to make newbuild and retrofit decisions years ahead of a vessel entering service, which means committing to a fuel pathway today based on where the technology, infrastructure and regulation are likely to be once that ship is actually sailing a decade from now — a genuinely difficult bet given how fast the picture is still shifting.
Methanol vs. Ammonia vs. LNG: The Leading Candidates
LNG was the first widely adopted alternative marine fuel and remains in use across a meaningful share of the global fleet, but it is still a fossil fuel, and methane slip — unburned methane escaping during combustion — undercuts some of its climate benefit. Methanol and ammonia have both emerged as stronger long-term candidates precisely because each can, in principle, be produced from renewable electricity and either captured carbon or nitrogen from air, giving them a credible path to near-zero lifecycle emissions that LNG does not have on its own.
| Fuel | Fleet Readiness Today | Key Challenge |
|---|---|---|
| LNG | Established, meaningful fleet in service | Still fossil-based; methane slip limits climate benefit |
| Methanol | Dozens of dual-fuel vessels in service or on order | Lower energy density than conventional fuel; green supply is limited |
| Ammonia | Mostly pilot and design stage for container ships | Toxicity requires new safety systems and crew protocols |
Real Fleet Orders: Methanol's Head Start
Methanol has moved furthest, fastest. Maersk put the first methanol dual-fuel container vessel into commercial service in 2023 and has continued placing orders since, including a deal with a Korean shipbuilder reportedly worth over a billion dollars for a batch of large methanol-fueled container ships, alongside additional orders from Chinese yards for mid-sized dual-fuel vessels. Across its announced orders, Maersk has described a goal of moving roughly a quarter of its ocean volumes on green or low-emission fuels by 2030, which gives a sense of how central methanol has become to at least one major carrier's strategy rather than being a token pilot program. Other large carriers have placed their own methanol-capable newbuild orders as well, though with less public detail on exact volumes and timelines.
What makes methanol practical in the near term is less about the fuel's chemistry and more about how it fits existing engine technology. Methanol dual-fuel engines are a comparatively modest adaptation of conventional marine diesel engines, which has let established engine manufacturers bring certified methanol engines to market faster than an equivalent ammonia engine, since ammonia combustion raises different safety and emissions questions that engine makers are still working through. That head start compounds over time — more methanol vessels in service creates more commercial pressure to build out methanol bunkering, which in turn makes methanol a safer newbuild choice for the next carrier weighing its own alternative marine fuels strategy, reinforcing methanol's lead even before ammonia's safety questions are fully resolved.
The Bunkering Infrastructure Problem
Building the ships has turned out to be the easier half of the problem. Methanol is a low-flashpoint fuel that requires different handling, storage and transfer procedures than conventional bunker fuel, and very few ports currently have the infrastructure to refuel a methanol-powered vessel at commercial scale. Early bunkering operations have had to rely on ship-to-ship transfers using dedicated barges — Antwerp-Bruges has handled green methanol transfers of several thousand metric tonnes this way, and Shanghai completed its first methanol bunkering operation in 2025, with the port publicly targeting roughly a million tonnes of green methanol bunkering capacity by 2030. Until that kind of infrastructure exists at most major container ports rather than a handful of pioneers, methanol-fueled vessels will remain constrained to specific trade lanes where refueling is actually available, which in turn shapes which routes carriers can realistically deploy these ships on.
Why Ammonia Lags Behind, and Why It Might Still Win Long-Term
Ammonia carries real advantages on paper: it contains no carbon at all, so burning it produces no direct CO2 emissions, and it can be produced at scale using existing industrial processes adapted to run on renewable electricity. But ammonia is also toxic to humans in ways methanol is not, which means ammonia-fueled vessels need more extensive safety systems, different crew training, and more cautious port-side handling protocols before regulators and insurers are comfortable with widespread deployment. That is why ammonia's progress in container shipping specifically has lagged methanol's, even though some analysts still expect ammonia to become more important for larger vessels over the next decade once these safety questions are further resolved, particularly for the bigger ships where methanol's lower energy density becomes a bigger practical constraint on cargo space and range. For transportation logistics planners, the practical implication is that ammonia-fueled capacity is a multi-year-out consideration rather than something to factor into near-term route planning, while methanol is already a live variable on specific lanes today.
How This Shows Up in Freight Rates and Routing
Green methanol and ammonia currently cost meaningfully more to produce than conventional bunker fuel, and that gap is being layered on top of separate new compliance costs from the IMO's global carbon levy, which is being phased in under the organization's broader net-zero framework. The practical result for shippers is a freight rate environment where decarbonization costs are becoming a persistent, structural line item rather than a temporary surcharge, similar to how bunker adjustment factors have long tracked conventional fuel prices. Carriers running dual-fuel vessels also have an incentive to prioritize high-volume, well-served routes where green fuel bunkering is actually available, which means alternative-fuel capacity may concentrate on a subset of major trade lanes before it becomes broadly available everywhere.
There is also a second-order effect worth watching: as carriers retire older, single-fuel vessels and replace them with dual-fuel newbuilds, overall fleet capacity on some routes may tighten during the transition period, since new ships take years to deliver and older tonnage does not disappear instantly. A shipper relying on transportation logistics partners who track these fleet-renewal cycles, rather than only quoting the current spot rate, is generally better positioned to anticipate rate movements tied to the fuel transition rather than being surprised by them when a specific carrier's surcharge structure changes.
The Regulatory Driver Behind the Fuel Shift
None of this investment is happening purely out of goodwill. The International Maritime Organization's net-zero framework, approved in draft in 2025, sets a fuel-intensity standard that tightens year over year, alongside a pricing mechanism that charges vessels failing to meet it. Because that standard is measured on a lifecycle, well-to-wake basis rather than tied to one specific fuel, it structurally favors whichever low-carbon fuels a carrier can actually source at scale — which is exactly why methanol and ammonia, rather than any single "winner," are both being pursued simultaneously. Our broader look at green logistics and reducing carbon footprint covers how this regulatory pressure is reshaping freight forwarding more broadly, beyond just vessel fuel choice.
How RR Brothers and Logistics Can Help
As carriers phase in methanol and ammonia-capable vessels across global trade lanes, our sea freight team at RR Brothers and Logistics tracks which services and routes are affected, how that is showing up in bunker-related surcharges, and where transit options remain most cost-stable for clients moving FCL and LCL cargo out of China. Rather than leaving clients to absorb fuel-transition costs as a surprise line item, we build current surcharge structures into quotes up front and help identify carrier options that fit a shipment's specific cost and timing priorities as this transition continues to unfold. For shippers who want their transportation logistics plans to hold up as the fuel mix underneath ocean freight keeps changing, working with a forwarder that actively tracks these shifts, rather than treating fuel surcharges as a fixed cost, makes a measurable difference over a full shipping year.
Frequently Asked Questions
LNG was the first widely adopted alternative marine fuel and remains in use, but it is still a fossil fuel with its own methane-slip emissions concerns. Methanol and ammonia can both be produced from renewable or low-carbon feedstocks, giving them a credible path to near-zero lifecycle emissions that LNG does not have on its own.
Methanol has a significant head start. Multiple major carriers, led by Maersk, have dual-fuel methanol vessels already sailing and dozens more on order from Asian shipyards. Ammonia-fueled container vessels remain mostly in the design and pilot stage, with toxicity and engine-safety questions still being worked through.
Most industry analysis expects at least a partial pass-through of the higher cost of green methanol and ammonia relative to conventional bunker fuel, layered on top of separate costs from the IMO's new emissions framework, though the exact impact will vary by route and how quickly low-carbon fuel supply scales up.
Bunkering infrastructure. Building out reliable, scaled supply of green methanol or ammonia at major ports is a slower process than building the ships themselves, and today only a handful of ports can refuel these vessels at commercial volumes.
