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Published online 8 February 2008 | Nature | doi:10.1038/news.2008.564
News: Briefing
Ship kites in to port
As a the SkySails cargo ship finishes its maiden voyage, Nature News looks at the logic behind towing a ship with a kite.
Is it a bird? Is it a plane?
No, it’s a giant kite towing a cargo ship. What's more, it helps to save engine power and fuel.
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I wonder if the idea to use Kites on top of already existing wind farms has been thought of yet.
This is the worst kind of politically correct impractical faddy nonsense! There was a very good reason why sailing ships were abandoned, even high-tech steel-hulled steel-masted steel-cable-stayed clipper ships with multiple masts and multiple sails, even in exchange for coal-powered sidewheel steamers! The equation does not even come close to being balanced! Saved 10 - 15% fuel with the wind running favorably? That must drop to about 1 - 3 % when 50 degrees off the wind. The real technology of a square-rigger is operating efficiently from the lightest breeze to a full force hurricane, which was done by modular sails that can be furled in sequence as the wind increased. To make the kite-sail work, you would need about 20 of them, to be furled in sequence for different wind speeds. This would require a crew, that requires food and wages, not to mention the price of purchase, maintenance, and repair of the gear. And you'd have to divert your course to follow the trade winds, like the square-riggers of old did. (London to New York via Spain, Azores, then westbound in the tropical easterlies to the Caribbean, Florida, the Carolinas, to New York) As long as oil continues to bubble out of the ground FOR FREE, it will be cheaper to burn the fuel and go straight line! The kite-sail will only make economic sense when oil goes to $500 per barell.
Steven, with respect, your comments presuppose that we can continue to burn oil as it bubbles out of the ground for free (hmm). However, as it's generally accepted that we require energy sources that will not add carbon to the atmosphere, it would be useful to arrive (or not) at that starting point before educating us on efficiency of sails vs coal-powered steamers.