By
Rebecca Gibson |
How is wind power harnessed to propel a ship using a Flettner rotor?
In layman’s terms, there is a pressure difference or imbalance between the sides of the rotor, which in turn generates thrust. Once captured, the wind energy is converted to supplement and compliment the power needed to propel the ship. Wind assisted propulsion is viable as the wind captured provides a renewable power alternative that is clean, abundant and 100% carbon neutral.
What makes Norsepower’s technology different to other Flettner rotors that have been around for years?
Norsepower has developed a modernised version of the Flettner rotor, a spinning cylinder that uses the Magnus effect to harness wind power to propel a ship. The Norsepower Rotor Sail Solution is currently the only proven technology on the market that captures significant amounts of renewable energy while the vessel is moving. Each rotor sail is made using lightweight composite sandwich materials, which ensure the rotor remains well balanced, offering a simple, robust, and high-tech, low maintenance solution.
Slow steaming has been widely used to reduce fuel costs in recent years. However, dropping service speed, particularly in the cruise and ferry market where passenger schedules have to be maintained, is not always an option. With Norsepower’s rotor sails, the main engines can be throttled back, provided that wind conditions are favourable. This not only reduces fuel consumption and emissions, but it also provides the power needed to maintain speed and voyage time. Essentially, it provides net fuel cost and emission savings, without impacting scheduling.
Norsepower’s Rotor Sail Solution is fully automated and senses whenever the wind is strong enough to deliver fuel savings, at which point the rotors start automatically, minimising crew time and resources. It can be fitted and installed as a retrofit on existing ships without off-hire costs, or during a newbuild project. The solution is typically delivered as a full-service solution that includes both delivery and maintenance of the hardware and software components.
Do you have any data to support these claims?
The first commercial application of Norsepower’s technology is onboard MS Estraden, a 9,700DWT ro-ro carrier. The vessel was equipped with two of Norsepower’s smaller rotor sails, which produce wind-assisted propulsion, and this has reduced fuel consumption by 6.1%. This saving was measured and independently verified by NAPA, a leading maritime data analysis, software and services provider. Working with NAPA, Norsepower has collected more than 18 months’ data to give our customers the assurance and proof that the technology can perform. To date, independent data analysis indicates that up to 20% fuel savings per year can be achieved on windy routes, with sufficient sized rotors, and appropriate service speed.
Is the technology suitable for the cruise and ferry market?
Norsepower rotor sails are particularly suited to cruise vessels and ferries, as well as the tanker, ro-ro, general cargo and bulk carrier markets. The sails are available in three different heights (18, 24 or 30 metres) with the main requirements for installation being deck space and electrical connections to the ship. What is very exciting for us is that our technology has received interest from the cruise and ferry market, and it is highly feasible that our rotor sails will be installed on a few newbuild vessels in the near future.
What does Norsepower’s technology mean for the future of wind-assisted propulsion?
There is no denying that renewable energy is the future of shipping and that it’s here to stay. We are proud to be the first company to use renewable energy on a large commercial vessel while it is in motion. With the data collected from MS Estraden, we have the confidence to project up to 20% average fuel savings for vessels using Norsepower’s rotors. As we expand commercially, we’ll be able to develop larger rotor sails, which will equate to more fuel savings for shipowners and cargo owners paying for the fuel. We’re very excited to be breaking ground for returning to the natural way of shipping. The technology is proven, and we now encourage the shipping industry to embrace it.