Flettner Rotor Trial Delivers Real-World Fuel Savings

Maersk Pelican (image courtesy Norsepower)

Published Oct 25, 2019 11:53 PM by The Maritime Executive

Wind propulsion company Norsepower announced this week that a trial of its advanced Flettner rotors aboard a product tanker produced exceptional results: an 8.2 percent reduction in fuel use from September 2018 to September 2019. The outcome falls neatly within the predicted 7-10 percent range of fuel consumption savings that Norsepower expected at the start of the trial.

In partnership with Maersk Tankers, Energy Technologies Institute and Shell, Norsepower installed two of its rotor sails aboard the LR2 tanker Maersk Pelican in August 2018. After one year in operation, the aggregated total fuel saved came to about 8.2 percent, equivalent to about 1,400 tonnes of CO2. Over the course of the test, the tanker operated in conditions ranging from tropical to arctic conditions, voyaging between Europe, the Middle East, Asia and Australia.

 The savings were confirmed by comparing detailed ship performance information to a baseline established with full scale measurements and computational analysis done for the vessel prior to the rotor sail installation. Independent experts from Lloyd’s Register’s (LR’s) Ship Performance Group have analyzed and validated the performance data, and Norsepower says that technical and operational insights for performance studies will be published soon. 

Norsepower's rotor sails are large, cylindrical mechanical sails that spin to create a pressure differential, the Magnus Effect, whicl propels the vessel forward. When wind conditions are favorable the main engines can be throttled back, saving fuel and reducing emissions, while maintaining speed and voyage time. Based on simulations, Norsepower estimates that applying its rotor sail technology to the entire global tanker fleet would reduce annual CO2 emissions by more than 30 million metric tonnes. 

“During the one-year trial period on Maersk Pelican, crew and operators have reported positively on the usability, safety and performance of the Rotor Sails in all conditions,” says Tommy Thomassen, CTO at Maersk Tankers. "We will closely follow the development around the financial and commercial viability of the technology for potential future installations on some of our other larger vessels, while we have decided that Maersk Pelican will continue to sail with the Rotor Sails.” 

“With the Maersk Pelican, there are three vessels in daily commercial operation using Norsepower’s Rotor Sails," said Tuomas Riski, CEO at Norsepower. "Each of these cases represents a very different vessel type and operational profile, demonstrating the widespread opportunity to harness the wind through Rotors Sails across the maritime industry.”