Maritime Journal –
The French company Omega Sails has introduced a kite system for boat propulsion that is claimed to give considerable savings in fuel.
The kites are a unique round conical shape that is held open with an inflatable tube.
The designers claim that the kites are easy to deploy and stow and in their present form they are available in sizes for boats up to 20m in length. In their stowed form the kites fit into a container mounted on the foredeck.
For the larger sizes the kite line is operated by a small electric or hydraulic winch that allows the height of the kite to be controlled remotely from the wheelhouse.
On deployment, the small diameter tube the gives the kite its shape is inflated and then the kite is launched with the boat heading downwind.
Once launched, the kite can operate effectively over an arc of 60° either side of the downwind line, thus allowing the kite to be effective over a considerable range of wind directions.
The Omega Sails kite has been tested on a number of different vessels including on one Atlantic voyage from the Canaries to Guadeloupe when the kite was the only means of propulsion used.
On this voyage, the 10m power catamaran averaged close to 5 knots.
Omega Sails is claiming that the kite can maintain a speed of 5 to 6 knots when the wind is blowing at between 15 to 30 knots.
A more demanding application has been found on 20m fishing boats operating from the Brittany coastline.
Here the fishermen have found that they could use a kite of an effective size of 200 square metres for about 40% of the time and this has led to fuel saving of between 15% and 25%.
With the sail costing in the region of €20,000, this means that it could be possible for the cost of the kite to be recovered in just over one year with this sort of intensive use.