anemoi's mechanic rotor sails capture wind power to propel ships into a sustainable future

introducing anemoi’s rotor sails

Seeking a more sustainable future for the marine industry, London-based company Anemoi introduces a rotor sail solution that harnesses the power of the wind to propel ships. Originally known as Flettner rotors, rotor sails are an energy-saving technology for shipping. These modern mechanical sails consist of tall cylinders that, when set in rotation, harness the renewable power of the wind to propel ships. This additional thrust significantly reduces fuel consumption and reduces pollutant emissions into the atmosphere.

rotor sails consist of tall cylinders that, when set in rotation, harness wind power to propel ships | all images courtesy of Anemoi

How do rotor sails work?

The rotor sails are built to rotate by a motor. When a wind current hits the spinning rotor sails, a pressure difference is created. This creates a thrust force that gives the ship auxiliary propulsion and can be used to increase the ship’s speed or reduce the consumption of the main propulsion system. According to Anemoi, by installing rotor sails on every suitable ship in the world fleet, the potential annual savings would be: 5-30% fuel and emissions reduction per vessel, 17 million tons of fuel, and 56 million tons of carbon.

The UK-based company offers a wide range of rotor sail options, making standard sizes suitable for most ship types.‘Our cleverly engineered core design is easily scalable so we are able to tailor the Rotor Sail size based on individual vessel designs in order to optimize performance’, the team explains. ‘Having this flexibility means Anemoi Rotor Sails are suitable for almost all commercial vessel types, including all sizes of Bulk Carriers, Tankers, Gas Carriers, RoRos and Ferries.’

easy deployment

For vessels with complex cargo operations, Anemoi has developed a patented rail system that allows sails to be moved along the ship’s deck so that cranes can load and unload effectively and without obstruction. Depending on the deck layout, the sails can be moved either from side to side or along the length of the ship. This system ensures that the mechanism has no impact on the ship’s operation.

If air draft and cargo operations both come into consideration, Anemoi also offers a Folding Deployment System. Rotors Sails fitted with this system can be lowered from vertical to horizontal, to allow the vessel to pass under low bridges and/or avoid impact to cargo loading and unloading. Both the Rail and Folding Deployment Systems require minimal crew input and take only 10 minutes to complete operation.

the UK-based company offers a wide range of rotor sail options, making standard sizes suitable for most ship types

Seamless installation, easy operation, and minimal maintenance

The number of rotor sails on a ship is determined by factors such as ship size and deck space. Rotor sails can be installed on new ships or retrofitted on existing ships. For retrofits, installation is performed during standard or special surveys, and rotor sails are hoisted on board within a few hours.

As part of the equipment delivery, the company offers a customer service package and comprehensive crew training. Anemoi rotor sails have a 25-year service life and require minimal maintenance. All required maintenance is timed to coincide with typical vessel maintenance activities to ensure vessel operations are not impacted.

when a wind current hits the spinning rotor sails, a pressure difference is created