Denmark has distinguished itself as a key player in developing the green maritime corridors of tomorrow. Here, ships will be able to refuel zero-emission fuels, and both ports and fuel systems will be geared to handle green fuels.
A.P. Moller - Maersk is one of the companies driving the transition to green fuels. The shipping company already has a fleet of methanol-powered container ships that help demonstrate how green fuels can work in practice. And more are on the way.
The methanol ships are important because they can exploit the new fuel supply and refuelling solutions being developed in connection with the green maritime corridors of the future. With ships that can actually sail on green fuels, a market emerges that motivates ports, manufacturers, and authorities to invest in the necessary infrastructure. But the number one challenge is that the infrastructure and technologies are not 100 per cent in place, says Michael Bruhn Barfod, PhD and Associate Professor at DTU:
"Green fuels alone do not solve the problem. A ship can sail on methanol, ammonia, or other types of e-fuels—but if the port cannot supply fuel to ships, or if the legislation does not support the transition, no real green corridor will be created. We simply don't have all the solutions yet. There are both operational and technical challenges that need to be solved before alternative fuels can become a reality on a large scale, and we're starting to see a sense of urgency to achieve the goals of the green transition."
Achilles heel of the transition
Michael Bruhn Barfod is a key researcher in the DTU project IMAGES, which is supported by the NORDEN // Orient's Fond foundation and the Danish Maritime Fund. In the project, he is involved in developing decision-making methods and analyses that will make it possible to establish green maritime corridors in practice—and assess their economic and environmental effects. The project will help decision-makers find out what rules, requirements, and framework conditions are needed for the corridors to become a reality—and thus ensure that Denmark can continue to be a frontrunner in green shipping.
The concept of the green maritime corridors is still under development and serves as test laboratories where the maritime sector is testing new low and zero-emission fuels. The experiences gained will form the basis for scaling up technologies and rolling them out across major global trade routes.
And it is urgent to find good green solutions. Shipping is responsible for around three per cent of the world's carbon emissions. The United Nations' International Maritime Organization, IMO, has formulated a strategy for significant reductions in greenhouse gas emissions—at least 40 per cent by 2030 compared to 2008 levels and full climate neutrality by 2050.
"We will never achieve zero emissions without new fuels and new ways of operating ships—whether it's methanol, ammonia, hydrogen, or something else entirely. However, alternative fuels are far from being the only solution. Carbon capture can also play a role, even if the technology is expensive, and carbon storage is still uncertain. The direction is still unclear, so we need to keep more options open. Wind-assisted operation can provide quick energy savings, and in the long term, even nuclear power can come into play as part of the solution," says Michael Bruhn Barfod.
Carbon taxation must be increased
Among the challenges for establishing green maritime corridors is not only the development of new technologies and solutions. It is also important to get the infrastructure in place. Ports are key here. Where they used to act as hubs for importing, exporting, and loading of fossil fuels such as oil and coal, they are now transitioning to energy hubs. Here, both fuel for the ships and the further transport of goods must be green.
The establishment of the green maritime corridors also requires close cooperation between shipping companies, ports, and authorities, where both ships, fuels, and port facilities support green operations. Finally, the transition requires a clear international plan for how carbon emissions should be reduced.
That's exactly why the industry was very disappointed when IMO met in London in October 2025 to negotiate a global agreement to reduce carbon emissions in shipping. Expectations were high, but the countries could not agree, and the result was a serious setback for the work to regulate the sector, says Michael Bruhn Barfod:
"It's frustrating. We're working to test how the current regulations affect a fleet of ships and how shipping companies can most cost-effectively meet the requirements to reduce their emissions—whether it requires technical upgrades or a shift to other fuels. When reviewing the current rules, it is clear that carbon taxation must be significantly increased before a real incentive to switch to zero-emission fuels arises."
Confidence in climate-friendly shipping
This is precisely why it is really important when some players choose to take the lead—even before it is required by law. One of them is A.P. Moller - Maersk. In 2021, the shipping company ordered the world's first methanol-powered container ship. Today, both A.P. Moller - Maersk and a number of other shipping companies have decided to build ships with dual fuel engines for methanol and conventional fuel. This is based on the expectation that methanol will be available for shipping at an attractive price and with a low climate impact. Bo Cerup-Simonsen, CEO of the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping, says:
"It has been very important that a leading player took the lead and showed that it was possible to build and operate the ships. Not only did it inspire many in the industry to step up efforts on climate action, it also gave authorities increased confidence that climate-friendly shipping is possible, and thus a boost to the launch of regulation."
Expecting a multi-fuel future
As an independent research centre, the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping works with research, partnerships, and the development of technologies to reduce emissions in global shipping. Specifically, a number of alternative energy sources and fuel types such as methane, methanol, and ammonia are being investigated and argued that they will become part of tomorrow's fuel mix.
"We expect that in future there will be a continuous development of the regulatory framework, which will drive the start and continuous scale-up of the use of green fuels. At the same time, energy efficiency will be increased, which will reduce the total energy consumption in relation to the transport work. We expect several different fuels to be used, and the industry must therefore adapt to a multi-fuel future," says Bo Cerup-Simonsen.
Chicken and egg paradox
He points out that today fossil fuels account for more than 99 per cent of energy consumption, but that demand for biomass-based fuels such as methane, methanol, and ethanol is increasing.
In the long term, ammonia is also expected to play a significant role. The first commercial ships with ammonia engines will be launched in 2026, and extensive work is already underway to establish the production of climate-friendly ammonia—for example for utilization as fuel for shipping. However, no matter how fast the technology evolves, it will all come to a halt if supply and demand are not linked. Who will supply the green fuel—and who will demand it?
"There's a chicken and egg paradox in the industry. An entire system of fuel production, ports, ships, and goods owners must be established—that is the companies that own the goods and pay for the transport. And the question is who will demand climate-friendly shipping and ultimately pay for it," says Bo Cerup-Simonsen, elaborating:
"So far, it has been found that only a small part of the freight market will voluntarily pay extra for green transport. Therefore, it requires regulation from the authorities to create a broad demand in the industry and thus a real business case for green shipping, so that the entire system can be established."
