The ability of a Flettner Rotor to exploit wind power is well known. Now a Finnish company is trialling the technology on a Maersk LR2 tanker
Norsepower Oy Ltd was established in 2012 and the aim of modernising the traditional Flettner Rotor, turning it into a commercially viable product. Now the group are spearheading a new project to trial the design on a commercial tanker.
Explaining its innovative solution, Norsepower Oy Ltd partner Jukka Kuuskoski said: “The rotors are made from composite materials, making them light and very strong,” and at 30 m tall, the carbon fibre sandwich Flettner Rotors impose a loading that means they are best suited to larger vessels.
The rotating sails have been installed onboard the product tanker Maersk Pelican and it is expected that the rotors will produce a reduction in fuel costs and associated emissions on typical shipping routes of between 7 and 10%. When wind conditions are favourable the main engines can be throttled back, saving fuel and reducing emissions, while maintaining speed and voyage time.
As well as the physical structure, Norsepower has updated the control mechanism to include automatic software-driven functions. The Flettner Rotors require a small amount of energy to spin, but the payoff is the additional forward energy. The speed of the spin and the direction of the Flettner Rotor is controlled by a variable speed electric motor requiring 15 to 35 kW, depending on the size of the rotor. The whole operation is fully automatic and requires no input from the crew.
“The use of wind propulsion technology onboard a product tanker vessel could take [the industry] to a new playing field”
Alongside Norsepower Oy, Maersk Tankers, Energy Technologies Institute (ETI) and Shell Shipping & Maritime are project partners on the installation of two Norsepower Rotor Sails onboard the Maersk Tankers Long Range 2 (LR2) product tanker vessel.
““This project is breaking ground in the product tanker industry,” said Maersk Tankers chief technical officer Tommy Thomassen. “While the industry has gone through decades of technological development, the use of wind propulsion technology onboard a product tanker vessel could take us to a new playing field.”
The product has now completed rigorous land testing, including thorough testing of various mechanical and performance criteria, and is the first Flettner Rotors design to be Class approved for use on a product tanker. Extensive measurement and evaluation of the effectiveness of the Flettner Rotors will now take place to test the long-term financial and technical viability of the technology. Independent experts from Lloyd’s Register’s Ship Performance team will analyse the performance data during the test phase to ensure an impartial assessment before technical and operational insights, as well as performance studies, are published.
ETI programme manager Andrew Scott said: “We commissioned this project to provide a unique opportunity to demonstrate the untapped potential of Flettner Rotors. Auxiliary wind propulsion is one of the few fuel-saving technologies that is expected to offer double-digit percentage improvements.”
Shell Shipping & Maritime vice-president Grahaeme Henderson added: “The shipping industry faces a major challenge in how it can economically ship the increasing amounts of goods and energy the world demands, whilst lowering its environmental impact. We see significant advantages in embracing, testing and driving innovative technologies that we believe show real promise in helping the shipping industry meet this challenge.”
Norsepower Oy’s Mr Kuuskoski noted that the rotors require deck space, making them suitable for tankers, but less so for container ships. Furthermore, they are better suited to vessels on long voyages, such as tankers that are crossing windier oceans.