|The MV Beluga Skysails at christening. Click to enlarge.|
The MV Beluga SkySails is equipped with a towing kite measuring 160 square meters for the first phase of operations. The company anticipates that in this first phase the ship will consume 10-15% less bunker fuel. Later, when the sail is scaled up to 320 square meters in the course of the coming year in order to increase efficiency on the high seas, potential savings of 20-30% are “definitely feasible and realistic,” according to the company.
Beluga is equipping two larger multi-purpose heavy-lift project carriers of the Beluga P1-series with SkySails systems in the near future; the two ships are currently under construction. On these, kites having a sail area of as much as 600 square meters will be used. The company anticipates fuel savings of up to ten tons daily.
|The SkySails system. Click to enlarge.|
The SkySails system consists of a large towing kite similar to a paraglider connected to the ship via a towing rope, flown between 100 to 500 meters of altitude, and managed by a fully automatic control pod. At an altitude of 100m the average wind speed is between 10% and 20% higher than at an altitude of 10m. 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 SkySails.
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.
SkySails plans a product range of towing kite propulsion systems with a nominal propulsion power of up to 5,000 kW (about 6,800 HP). On annual average, fuel costs can be lowered between 10-35% depending on actual wind conditions and actual time deployed. Under optimal wind conditions, fuel consumptions can temporarily be reduced up to 50%, according to SkySails.