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A Danish research initiative has entered a new phase as four high-tech wind sails are now installed on the Uni-Tankers’ vessel M/T Jutlandia Swan, aiming to gather real-world data on how wind-assisted propulsion can reduce fuel use and emissions in commercial shipping.
The sails—called VentoFoils—function like large vertical wings and are part of the Cleanship project, a government-backed research effort coordinated by the Technological Institute. The project’s goal is to measure the actual operational benefits of using wind energy aboard merchant vessels, especially under open-sea conditions.
Julie Tølbøl Rasmussen, senior project manager at the Technological Institute and leader of Cleanship, called the sail installation “a major milestone” that marks the project’s move from preparation to practical implementation. “By measuring this technology in real operational settings, we can deliver insights into the impact of energy-efficient solutions on board ships,” she said.
Wind-Assisted Propulsion Goes to Sea
The four VentoFoils installed on Jutlandia Swan are a form of rigid sail designed to generate aerodynamic lift using natural wind. This helps reduce the workload on the ship’s engines, potentially lowering fuel consumption and carbon dioxide emissions during voyages.
While wind-assisted propulsion has seen growing interest, real-world data remains scarce. That’s what Cleanship aims to change. Over the coming months, sensors onboard will continuously monitor fuel use, speed, engine load, and weather conditions to track the sails’ actual performance.
Kristian Larsen, Technical Director at Uni-Tankers, said this kind of testing is critical to understanding whether such technologies can be integrated into day-to-day shipping operations. “Wind-assisted propulsion has clear potential, but its value depends on how well it fits into regular operations,” he noted. “We’ll now get to see how these sails perform at sea, what they mean for fuel efficiency, and how our crew can work with them.”
Training the Crew for New Tech
The VentoFoils aren’t passive sails; they’re active components that require deployment and integration into the ship’s control systems. This makes crew readiness a priority.
Uni-Tankers is actively developing training programs, maintenance protocols, and operational procedures to ensure safe and efficient handling of the sails. “New technology only works when it’s understood and supported by the crew,” said Larsen. “We involve them as much as possible to make sure the knowledge and routines are in place.”
From Research to Industry Action
Funded by Denmark’s Environmental Technology Development and Demonstration Program (MUDP), Cleanship is more than just a wind sail testbed. It also evaluates the impact of modern biofuels and operational adjustments—like voyage speed and engine load—on emissions.
The project brings together a strong consortium of maritime stakeholders, including Green Instruments, the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping, Danish Shipping, and Danish Maritime. Together, they aim to produce reliable, independent data and clear best-practice guidelines that can help the broader shipping sector make informed decisions on decarbonization.
Between now and 2026, Cleanship will continue to collect operational data under different voyage conditions, using it to develop actionable recommendations for fleet operators.
Connecting Technology with Real-World Needs
Cleanship’s multi-pronged approach—testing wind propulsion, alternative fuels, and smart sailing strategies—reflects a growing trend in the shipping industry: the move from theory to practical, scalable solutions.
“We’re not just testing technology for its own sake,” said Rasmussen. “We’re trying to build a bridge between innovation and operations—to give shipping companies tools they can actually use to cut emissions and improve efficiency.”
