Geopolitical tensions have made one thing clear once again: decarbonisation is not just about climate, but also about energy security. This also applies to shipping, although it is a sector that is still often considered difficult to transition.

But in one segment, the phasing out of fossil fuels is closer than ever. Electrification is already a viable solution for ferries, especially on short routes of less than 100 km, which make up the majority of traffic in the Baltic and North Seas.

According to a analysis from Transport & Environment 48 percent of European ferry routes can already be electrified with available technology today. By 2035, this share is expected to increase to 60 percent.

Technological advances in recent years have significantly improved both battery capacity and charging speed. At the same time, battery prices have fallen significantly, making electric solutions increasingly competitive with diesel. Today, China and Europe are leading the way in ordering and deploying battery-electric ships.

Denmark has both the opportunity and the responsibility to lead the way

For Denmark, with more than 60 ferry routes connecting islands and neighboring countries, electrification represents an obvious opportunity – not only to reduce greenhouse gas emissions, but also to improve local air quality.

Danish ferries are among the ten most CO₂-emitting in Europe. Here, three ferry routes stand out in particular among the 50 most climate-intensive in Europe: Aarhus–Sjællands Odde, Hirtshals–Larvik and Hirtshals–Kristiansand. With an average fleet age of 27 years, the time is ripe for modernization.

Electrification can provide immediate air quality benefits in port cities such as Rønne, Aarhus, Frederikshavn, Sjællands Odde and Spodsbjerg, where ferries operate frequently and often close to residential areas. Here, sulfur oxide (SOx) emissions from ferries can exceed those from road traffic.

There are already good examples. Molslinjen's upcoming electric catamarans is one of the world's largest electrification projects in the maritime sector. But a broad rollout requires collaboration with players outside the shipping industry itself.

The biggest bottleneck is not on board – but on land

Today, the crucial limitation is no longer technological feasibility, but access to charging infrastructure.

It is not a theoretical challenge. Lack of capacity in the electricity grid is already affecting concrete projects in Denmark. As recently reported, insufficient electricity supply threatens development plans in the Port of Hirtshals – one of the country’s most important ferry ports. Without upgrades to the electricity grid, even well-established routes risk being stuck in fossil fuel solutions for many years to come.

But the challenge goes beyond the individual port. Across Denmark, limited grid capacity is developing into a systemic bottleneck. In many areas, the electricity grid has already reached its capacity limit, and connection times for new projects can range from one to two years. For project developers, access to the electricity grid is increasingly as difficult such as securing financing.

At the same time, the demand for electricity is increasing significantly. Electrification of transport, heating and industry, together with the expansion of data centres and hydrogen production, is expected to more than double Denmark's electricity consumption towards 2035. Electrification of ferries therefore does not occur in a vacuum, but in competition with other sectors for limited network capacity.

From ambition to implementation

There are a number of policy tools that can promote the electrification of ferries, and public procurement is a key tool here. Many ferry routes are operated under public service contracts, which gives authorities a strong opportunity to accelerate the transition. Zero-emission requirements in procurement can make public funds a driver for industrial scale-up rather than incremental improvements.

At the same time, a future government must ensure that electricity is not disadvantaged compared to fossil fuels. Reducing taxes, tariffs and connection costs for shore-side power is one of the fastest ways to improve the business case for electrification. In addition, better coordination between ports, grid companies and shipping companies is essential to avoid the delays we are already seeing today.

Denmark has a unique opportunity to lead the way, which requires both the rollout of electric ferries where it is already possible, but also an active effort to shape the regulatory and infrastructural frameworks that can scale the solutions.

However, this does not absolve shipping companies of responsibility. On the contrary, early investments, long-term planning and active dialogue with ports and authorities are crucial to realizing the projects. But it also underlines a fundamental point: the pace of the green transition is determined as much by the surrounding systems as by the ships themselves.

When the members of the new Danish government sit down to set their priorities, the maritime sector should be high on the agenda. The electrification of ferries does not primarily depend on new technological breakthroughs, but on whether infrastructure, regulation and investments are brought into play in the coming years. Public funds are limited and must be used wisely. Investments in electric ferries and the necessary infrastructure are a solution that both strengthens the climate, the environment and Denmark's energy security.

This debate post was published in Ingeniøren – MobilityTech on April 14, 2026, and was written by Katerina Davidova.