To the uninitiated, kite surfing is the sport of riding on a small surfboard propelled across water by a large kite to which the rider is harnessed. I was introduced to it when we wintered in Caberete, on the north shore of the Dominican Republic. The bay there is touted as being one of the world-class sites for kite surfing.
That is because on every sunny day, the air over the land is warmed and, as it rises, air is drawn off the water to take its place. This causes the consistent, steady onshore breezes that sweep in over the large open bay - perfect conditions for kite surfers. They begin appearing around 2 pm ready for hours of extreme sport. Besides jumping and stunts in the air, some kite boarders with the latest equipment and a good wind, can reach speeds of 80 to 90 km/hour and they can travel very long distances in a downwind.
With this background, I was intrigued to hear the following story, the truth of which I cannot verify but it does make for a good tale. It is about an entrepreneur from Marseille who used to windsurf for fun and exercise in the large bay there, The story goes that he was very happy with the sport until one day a couple of kite surfers showed up. Seeing their amazing speed and comparative lack of effort - a harness strapped around their waist is directly connected to the kite - he decided he had to try it for himself. It would not be inexpensive to take lessons and to rent or buy equipment but apparently it paid off for him. As he directly experienced through his body harness the powerful force of the wind in the kite, it suddenly dawned on him that that same power could be used to pull along the ships in his merchant fleet.
And so it came to be - huge new towing kite systems that capture the energy of the wind are now a reality and one kite can cut down on a ship’s fuel costs up to 20%. Considering that the cruise liner Queen Elizabeth II moves only six inches for each gallon of diesel it burns, the saving are worth a lot of investment.
Using sails to harness the power of the wind is an old story but it turns out that kites have several major advantages over sails. First the wind's speed near the surface is slowed down by friction with the water and there are much stronger winds higher up where a kite flies. The kite above a ship are in an unhindered position to capture the much greater energy accessible up there. Then important too, the kite is controlled by a computer that maintains the shape and position of the kite so that most of wind’s available energy is captured and is concentrated in pulling the ship straight ahead with an ‘even keel’ so it to slips through the water with least resistance.
Ship’s ‘sky kites’ are good news and hopefully we'll increasingly hear of more green ideas like this to help stop the pollution of our planet in time. Rie