Since 2013, we have operated with environmentally friendly hybrid technology. In 2020, we installed a rotor sail on M/V Copenhagen and in 2022 on M/V Berlin respectively, which operate on our route between Rostock in Germany and Gedser in Denmark. With that, we added environmentally friendly wind power technology to the list of green initiatives. With the rotor sail from Finnish Norsepower, we can further reduce CO2 emission from the hybrid ferries.
The rotor sail is based on the almost 100-year old concept of the Flettner rotor technology. It is a 30 metre tall, rotating cylinder, which by using the Magnus-effect contributes to pushing the ship forward. When the wind meets the spinning cylinder, the airflow accelerates on one side of the cylinder and decelerates on the opposite side of the cylinder. The change in the speed of airflow results in a pressure difference, which creates a lift force that pushes the ship forward perpendicularly to the wind flow direction.
A rotor sail has the optimum effect when it is windy and the wind comes from the side. The route between Gedser to the north and Rostock to the south is almost perpendicular to the prevailing wind from the west or the east. This gives us favourable conditions for using rotor sails on the crossing.
By installing a rotor sail, we expect to reduce the CO2 emission by four to five percent.