Shipping in the North Sea remains a major emitter of CO₂, accounting for a significant share of regional transport emissions despite EU climate policies pushing for a 55% reduction by 2030. Against this backdrop, the cross-border Zero Emissions Ports North Sea (ZEM Ports NS) project has piloted technologies designed to accelerate the transition toward cleaner maritime operations. Funded under Interreg North Sea, the initiative brought together partners from Sweden, Denmark, the Netherlands, and the UK to trial hydrogen and battery-based solutions.
Two hydrogen-powered inland vessels stand out among the outcomes. Dutch firm Future Proof Shipping converted diesel barges into the H2 Barge 1 and H2 Barge 2, both running entirely on green hydrogen. From a climate perspective, replacing diesel with hydrogen can eliminate direct CO₂ emissions, though lifecycle impacts hinge on the source of hydrogen production. In Europe, only around 7% of hydrogen is currently green, produced via electrolysis powered by renewables, according to the European Commission. Scaling this fuel pathway for maritime transport would require substantial expansion of renewable capacity and portside hydrogen infrastructure.
Infrastructure has been another focus of the project. A mobile hydrogen refueling station was deployed to address the absence of bunkering facilities for hydrogen vessels, highlighting both the potential and the bottleneck: without scalable and permanent infrastructure, pilot vessels risk remaining isolated demonstrations rather than catalysts for systemic change.
In Denmark, project partners tackled electrification through battery-charged ferries, developing methods to improve port-side charging efficiency. Ferries operating on fixed short routes are often viewed as the most viable early candidates for battery electrification, given the predictability of schedules and energy demand. Yet, large-scale electrification of ferry fleets will require not just efficient charging technologies but significant upgrades to port grid connections, where bottlenecks are already evident.
The project also emphasized safety and workforce readiness, developing a training program to familiarize maritime workers with hydrogen operations. This aspect addresses one of the more understated but critical barriers to decarbonization: operational safety standards and human factors in adopting new fuels. Without widespread acceptance and expertise at the workforce level, infrastructure and vessel investments risk underutilization.
According to Daan Geraets, the Dutch contact point for Interreg North Sea, the decision to focus on this region was deliberate: “If we look at experience, the research institutes that focus on the use of green energy in maritime transport are located in this region, so both the problem and the solution are here.” While this concentration of expertise supports innovation, the challenge lies in scaling solutions beyond demonstration projects.
The achievements of ZEM Ports NS underscore both progress and limitations. Pilot vessels and refueling prototypes show technical feasibility, but the broader maritime sector still faces structural barriers — from renewable hydrogen availability to port infrastructure investments and regulatory harmonization across borders. The North Sea, as one of Europe’s busiest maritime corridors, is both a proving ground and a stress test for whether zero-emission shipping can move from isolated pilots to regional adoption at scale.
