Sky Sails Promise Wind Energy for Fuel Reduction
by Jacob Gordon, Nashville, TN on 08.26.05
Commercial freight ships are among the largest vehicles ever made and are responsible for moving much of the world's transported goods. Ever since we got off using sailing ships, we've been using diesel. One of 100 technologies selected for the Eco-Tech awards at the World Expo in Aichi, Japan, Sky Sails is a system that puts giant sail kites on freight ships to use high-altitude winds to help pull them across the ocean. A computer autopilot controls the sails, determines optimal shipping routes, and even packs and unpacks the sails (no heave…ho!). The sails themselves have up to 5,000 sq meters (45,000 sq ft) of surface area, and contain giant compressed air compartments that keep them rigid. Getting up high is the key to catching those strong winds. The makers of the Sky Sails claim they go up to 500 meters (1,640 ft) high where they can catch strong air currents even in areas typically considered doldrums...
The cable to which the sail is attached moves around the hull of the ship on a track, a feature designed to eliminate heeling (tipping), that is the common behavior of sailing ships. The advantage of these contraptions, of course, is that ships can either go faster, or use less fuel (freighters use diesel). The company claims they can realize as much as 50% fuel savings. Sky Sails at this point are in their "virtual" stages, but the German company has recently acquired a more than 15 ton vessel for use as a prototype. Keep your eyes open next time you’re on a plane over the ocean. If you see one, don't be too shocked if it's got an ad on it. ::Sky Sails
Now if only it had solar panels on it, and a cable running down to the ship!
Kite surfing... for tankers! Thats really cool. I love sailing, I wish more commercial boats would use some kind of sail to increase efficiency.
This is one of those occasions where I'm scratching my head wondering why didn't anybody think of this before? One of the reasons might be materials. New materials make this idea viable. You're also talking about retraining what is usually no more than a ten man crew on these tankers who do little else than punch a few buttons. This will only work if again, the sail can be deployed and reeled back in easily and automatically. Quite a design challenge.
Wow! What a great idea. Let's hope this one actually pans out.
Oh, and on a petty nitpicky note: You write "Ever since we got off using sailing ships, we've been using diesel." Did you forget about coal? Sailing ships were first replaced by coal-powered steamships that ruled the seas for the later half of the 19th century and were stilled largely used during early 20th century.
cos the idea has been around for a while and not got past prototyping. It has many practical challenges and this is an industry that is very conservative about making changes: I asked a big shipping mogul I know & he reckons it'll never fly.
Just one question; how does one get the sail up into the sky especially if it's not windy at sea level?
Making the sail with cavities filled with helium holding it up like an air ship would solve some problems.
The videos they have on there site make it look like a real expensive kite and not much of a tug since like a kite they have little or no control maybe what they should be working on is a larger one with 100's of small wind turbines to produce electricity maybe at thouse hights enough energy could be produced to lower a decent percent of the disel they net to use to run course bringing them back down with the turbines might be a problem depending on the trubines materials and designs also solor panels on the top was a good idea and no reason the tug of the boat still would work when in the right conditions