A new rotor sail wind power technology for ships was successfully tested by Norsepower Oy Ltd and Bore Ltd. The Norsepower Rotor Sail Solution was verified by NAPA and financed by VTT Technical Research Center of Finland. In a test sail across the North Sea, using a single small Rotor Sail, nearly 2,6% fuel savings were achieved. Results show that the new technology has a 4-years payback period.

Norsepower Rotor Sail on the ramp house of mv Estraden

Image: Norwsepower

After the trials, Norsepower and Bore engineers believe that the full two-rotor system on MV Estraden has a potential to achieve 5% fuel savings, increasing significantly the system efficiency. Norsepower expectations are for 20% fuel savings after the new technology is applied on board vessels with multiple, large rotors and sailing on tailwind routes.

At the moment, Norsepower Rotor Sail Solution is installed on board MS Estraden. The vessel is 9,700 DWT Ro-Ro carrier of Finish Bore, which is the country’s leading Ro-Ro shiping company. MS Estraden operates on a regular service between the UK and Netherlands, sailing across the North Sea windy corridors, reaching an approximately 16-knots speed.

Norsepower wind sensors at the aft mast

Image: Norsepower

Tuomas Riski, the Norsepower Chief Executive Officer, said:

“The successful trials of our wind technology are a ground-breaking moment not only for Norsepower, and also the wider development of wind propulsion technology for shipping. The results suggest that when Norsepower technology is implemented at scale, it can produce up to 20% net savings in fuel costs with a payback period of less than four years at current fuel prices, confirming that wind technologies are commercially-viable solutions that reduce fuel and carbon emissions in the industry.”

While the new technology trials were measured and analysed, there was an ongoing monitoring system. It was achieved by using measurements from maritime data analysis, software and service provider, Finland’s VTT Technical Research Centre and NAPA.

Lifting of Norsepower Rotor Sail on the vessel

Image: Norsepower

It took about 6 months for the data to be collected by VTT Technical Research Center, while both, the Rotor Sail technology and automation system were operating 99% of the time.

The final results showed that Norsepower Rotor has a capability of significant increase of fuel savings, achieved after a large amount of thrust force was produced.

The Rotor Sail was activated and deactivated at random intervals, after the vessel’s baseline profile in normal operation was established. The main purpose was to verify that any measured effect was solely due to the sail, and that any benefit was measurable across the vessel’s operating profile. NAPA’s analysis, during the trial, showed an average verified fuel savings of about 2,6%. The experimental survey was conducted using ClassNK-NAPA GREEN. It is a software for monitoring and verification of the vessel’s performance, developed by NAPA and ClassNK, which are two of the leading class societies in the world.

Esa Henttinen, NAPA’s Executive Vice President said:

“As impartial data analysis and verification is vital for charterers and shipowners looking to retrofit efficiency technology onto vessels, we used both randomised trialing and advanced statistical modeling to ensure objective results. The Rotor Sail offered clear savings against this criteria and adds to a growing list of innovative eco-efficiency technologies that have proved themselves through robust data collection and advanced analytics.”

Jörgen Mansnerus, Bore’s Vice President said that their company was proud to be the first shipowner to install the Norsepower Rotor Sail and first to demonstrate that wind propulsion technology had verifiable 5% fuel savings on a yearly basis. Also that it can be retrofitted without any off-hire costs, and is extremely easy to use in practice. He said that their goal was to find ways to establish sustainable shipping with minimal impact on the environment.

The new Rotor Sail Solution of Norsepower is an improved version of the Flettner rotor, which is a spinning cylinder using the Magnus effect to harness wind power to propel a ship. In good weather conditions with favourable winds, Norsepower Rotors sails allow the main engines to be throttled back. This leads to fuel saving and emission reduction, at the same time, the power needed to maintain vessel’s speed is provided without any voyage delays.

The new technology can be used onboard newbuild ships or can be retrofitted onboard existing vessels without off-hire costs. The installation process of Rotor Sail Solution was completed in two stages: first the required foundations were installed during a normal dry-dock stay and later, the 18-metre-high rotor was installed in an ordinary stay for seven hours in the harbor.

Norsepower is a member of a joint program of Carbon War Room and UCL Energy Institute. Together with several other technology companies, Norsepower is working on fast track adoption of emerging wind-propulsion technologies by the shipping industry.

Jose Maria Figueres, Carbon War Room Chairman said:

“Modern wind systems are demonstrating measurable and meaningful fuel savings for ships. As wind propulsion, air bubble systems and other ground-breaking technologies are increasingly adopted and become mainstream, the industry will reap the rewards of lower fuel costs—more sustainable than those from short-term price decreases, and be able to stay ahead of external pressures”