|The components of the SkySails system. Click to enlarge.|
The SkySails towing-kite propulsion system uses offshore wind power (a kind of “wind hybrid” propulsion assistance) to cut a ship’s fuel consumption by up to 50%, thereby also reducing emissions.
The SkySails technology is ready for market entry exactly at the right time. The rising and continuously high price of oil is a matter that ship owners are already dealing with in order to be competitive in the present and future market. Furthermore, significantly tightened emission regulations, through which increasing costs will accrue, are being put into place.
Offshore wind energy is an unbeatable cost-effective propulsion source available in large quantities, and we expect to gain a considerable competitive advantage by using the innovative SkySails system as a pioneer in this field. We are convinced that the SkySails system will revolutionize the cargo shipping industry.—Niels Stolbergs, captain and managing partner of the Beluga Group
The first SkySails system (SKS 160) will be installed on the newly built 140m multipurpose-heavy cargo freighter MS Beluga SkySails, with the first demonstration cruises using the new system taking place in 2007.
With the proof-of-concept provided by the MS Beluga SkySails, SkySails hopes to begin regular sales in 2008.
The SkySails system consists of a large towing kite similar to a paraglider of up to 5,000 m2 in area, which is connected to the ship via a towing rope, and managed by a fully automatic control pod. Route optimization software helps chart a course designed to maximize the wind power benefit.
The cross-sectional profile of the aerofoil is adjustable via the use of compressed air to achieve optimal aerodynamic properties at all wind speeds and under various weather conditions. At very high wind speeds the performance of the aerofoil can be reduced without having to reduce the area. (No “hauling in” sails.)
The lift of the aerofoil offsets its lateral pull on the ship, thereby eliminating the potential danger of heeling present with conventional sail systems, according to the company.
A traveller car takes up the towing line from the kite, and leads it to a winch. The traveller car moves on a traveller fixed circumferentially along the outside of the hull. The traveller takes up and transmits the strain of the towing kite. The location of the traveller car—and hence the point of attachment of the kite to the ship— is dependent on the ship’s course and the wind direction.
The towing kite is designed to be flown between 100 to 500 meters of altitude.
|SkySails can boost speed or decrease fuel consumption.|
By using the SkySails technology ship owners can either increase speed of the ship or reduce fuel consumption to reduce the ship’s operating costs.
A study from the University of Delaware in 2003 found that the world shipping fleet (including military vessels) consumes approximately 289 million tons of fuel (about 2 billion barrels, or about 5.5 million barrels per day) annually, with 80% of that represented by heavy fuel oil (HFO). That’s a figure about twice what was earlier thought, and hence with twice the emissions load.
Emissions from cargo ships are disproportionately damaging to the environment because they run on low-grade, high-sulfur fuel oil. Lloyd’s Register Quality Assurance estimate that shipping traffic is responsible for more than 7% (10 million tons) of the total worldwide output of sulphur dioxide.
SkySails calculates that the use of its technology worldwide could reduce carbon dioxide emissions by more than 146 million tons (about 0.6% of the entire global energy-related emissions of CO2).
Skysails estimates the potential upgrade market for its system at more than 40,000 ships. Through 2013, the company is targeting less than 1% of that market—about 400 ships.
”Updated emissions from ocean shipping”; Corbett, J. J., and H. W. Koehler; J. Geophys. Res., 108 (D20), 4650; doi:10.1029/2003JD003751,2003.