Wind Power Technology for Ships Tested at Sea
Norsepower’s Rotor Sail Solution, a new wind propulsion technology for ships, has passed its sea trials with flying colors.
The Norsepower Rotor Sail Solution was installed on the 9,700 DWT Ro-Ro carrier MS Estraden, owned by Bore, a Finnish Ro-Ro shipping company. The ship operates in a continuous service between the Netherlands and the UK, sailing through the North Sea’s windy corridors at speeds of 16 knots.
The sea trials, verified by NAPA and supported by VTT Technical Research Centre of Finland, confirmed fuel savings of 2.6% using a single small Rotor Sail on a route in the North Sea, said Norsepower Oy Ltd. With these fuel savings, the technology has a payback period of 4 years.
“Based on the trials, Norsepower and Bore believe that a full system on Estraden with two rotors has the potential to deliver 5% efficiency savings on an ongoing basis. Norsepower forecasts savings of 20% for vessels with multiple, large rotors traveling in favourable wind routes,” the company said.
VTT Technical Research Centre of Finland collected data over a six-month period, during which both the Rotor Sail technology and automation system was operational 99% of the time.
The results confirmed that Norsepower’s rotor is able to produce large amounts of thrust force, which enables considerable fuel savings.
Reinforcing VTT’s findings, NAPA conducted a randomised trial that found clear and significant savings, despite largely calm weather conditions throughout the study. After establishing a baseline profile of the vessel in normal operation, the Rotor Sail was activated and de-activated at random intervals to verify that any measured effect was solely due to the sail, and that any benefit was measurable across the vessel’s operating profile. The average verified fuel savings during the trial in NAPA’s analysis was 2.6%.
The trial was conducted using ClassNK-NAPA GREEN, the vessel performance monitoring and verification software developed by NAPA and ClassNK, the world’s leading class society.
“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,” said Esa Henttinen, Executive Vice President, NAPA.
The Norsepower Rotor Sail Solution is a modernized version of the Flettner rotor – a spinning cylinder that uses the Magnus effect to harness wind power to propel a ship.
When the wind conditions are favourable, Norsepower Rotor Sails allow the main engines to be throttled back, saving fuel and reducing emissions while providing the power needed to maintain speed and voyage time. Rotor sails can be used with new vessels or can be retrofitted on existing ships without off-hire costs.
“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,” says Jose Maria Figueres, Chairman, Carbon War Room.