© SAILWINT GmbH

Sailing ship with wind turbines generates power at sea

Far out at sea, the wind blows especially strong and steady – ideal conditions for a ship developed by the startup Sailwint, equipped with wind turbines. The ship can reliably generate wind power at sea, with its turbines also acting as sails.

In this design, the wind turbines have two functions: generating electricity from wind energy and providing thrust to propel the ship. Researchers first tested the concept with a 5.5-metre prototype, the so-called Proof of Concept. The trimaran, together with the installed wind turbines, weighs around 300 kilograms. Each turbine has a rotor diameter of 2.2 metres.

The prototype was recently deployed in the North Sea, in the German Bight between Cuxhaven and Helgoland, accompanied by the research vessel from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM. “It was a challenging test with wave heights of up to 1.8 metres,” said Nils Barnickel, founder of the startup Sailwint. “Each wind turbine can generate up to 1.5 kilowatts of power at wind speeds of 14 metres per second. During the test, when wind speeds ranged from 10 to 12 metres per second, the power output exceeded one kilowatt. This aligns very well with our earlier numerical simulations,” Barnickel said. The onboard batteries were successfully charged.

^{No power losses when sailing close to the wind}

During a test in the Baltic Sea at the end of 2025, the team gained valuable insights. The prototype successfully sailed at various angles to the wind, simultaneously generating electricity and propulsion. The results confirmed the simulation data collected in collaboration with TU Berlin. As the simulations predicted, the ship was able to generate full rated power without losses when sailing at an angle to the wind – with the turbines slightly off the wind, allowing the ship to generate propulsion while still delivering maximum turbine output.

^{Higher energy yield than offshore wind}

The design and control concept was developed by Nils Barnickel, who is leading the research project with his team and several research partners. He first conceived the idea for this project over 15 years ago during his doctoral studies. “Due to the high wind speeds at open sea and flexible locations outside larger offshore wind farms, the concept could deliver 30 to 50 per cent higher energy yield, as wake effects and wind shading are avoided,” Barnickel said, comparing his concept to traditional offshore wind energy. At the time, autonomous energy supply in Europe was not as much of a focus as it is today. In the future, wind turbine ships could play a role in this area. A follow-up project, with double the ship length and four times the energy output, is already in development and will demonstrate the rapid scalability of the concept.