A.P. Moller-Maersk is set to test wind-assisted propulsion on one of its container ships, planning to install a large Rotor Sail on an 8,700-TEU vessel next year.
The system will be provided by Anemoi Marine Technologies, a UK-based company, and this will be the first time a Rotor Sail has been installed on a containership, according to both companies.
As part of their agreement, Anemoi will design, build, and deliver a fixed Rotor Sail that is 5 meters in diameter and 35 meters tall. The installation is expected to take place in mid-2027 on a ship from Maersk’s Lima class.
After installation, the system will be tested during regular commercial operations, and the ship is anticipated to operate on routes across the North and South Atlantic.
Rotor Sails, also called Flettner rotors, utilize the Magnus effect to create lift from the wind, giving an extra push forward that can lessen the strain on a ship’s main engine. The savings in fuel and emissions depend largely on the ship's design, route, and wind conditions.
Interest in wind-assisted propulsion is growing among shipowners who want effective ways to enhance vessel efficiency and reduce emissions in the near term. While Rotor Sails have already been used on bulk carriers and other commercial ships, their use in the container sector has been more limited.
“Wind-assisted propulsion is among several promising solutions that could boost vessel efficiency and lower emissions,” said Ole Graa Jakobsen, Maersk’s Head of Fleet Technology.
“It has been tested in other areas of shipping, and we see this pilot with Anemoi as a great opportunity to gain practical experience and understand how it can fit into our fleet and the container shipping industry as a whole.”
Anemoi will assist Maersk throughout the engineering and installation phases, ensuring the Rotor Sail integrates smoothly with the ship's current systems.
“We’re thrilled to partner with Maersk on this groundbreaking project,” said Clare Urmston, CEO of Anemoi. “It showcases how collaboration can help promote wind-assisted propulsion.”
Established in 2015, Anemoi designs and installs Rotor Sails for large commercial vessels. The company's installations usually involve three to five rotors per ship, but the Maersk pilot will start with just one unit.
Anemoi states that each Rotor Sail can save about one tonne of fuel daily and reduce CO2 emissions by around three tonnes, although actual performance can vary with operating and weather conditions.
The Maersk project comes as the shipping industry seeks technologies to lower fuel use while looking for longer-term alternatives to traditional marine fuels.
For Maersk, this trial will provide valuable data on whether wind propulsion can be effectively integrated into container ship operations, where challenges like deck layouts, cargo handling, and tight schedules are more pronounced than with other vessel types.
The Rotor Sail is expected to go into service in mid-2027.