Wind farms are universally recognized as a clean, sustainable source of energy.  But like any other power plant, windmills are big, noisy and hard on the eyes.  People approve of them in theory, but not in their backyards -- or, in the highly publicized case of a proposed Cape Cod wind farm, in the shallow seas beside their vacation homes.

Enter Paul Sclavounos, an MIT engineer who's spent three decades designing gargantuan oceanic oil rigs that make the present generation of offshore windmills look like bathtub play.  Rather than anchoring them close to shore, Sclavounos wants to float windmills in the deep waters of the open ocean. 

"The good thing about going offshore is that you can't see them," said Sclavounos.  "If they can be pushed fifty miles offshore, there's plenty of real estate." 

Better sightlines aren't the only virtue of deep-sea windmills.  Winds at sea are stronger than those on land, and therefore generate more energy.  Because deep-sea windmills would be built in shipyards, floated out, and raised upright by adjusting their buoyancy, they could dwarf their grounded counterparts, which must be driven cross-country and erected with cranes.

Sclavounos believes offshore U.S. wind farms could annually produce a terawatt of energy -- some seven percent of all the energy used in the world.  Over the last two years, he's collaborated with the Department of Energy's National Renewable Energy Laboratory to model a floating system tethered by steel cables to the ocean floor.

"We don't have any more science engineering or development to do.  We've reached the stage of building one and testing it.  It's simply a matter of funding," said Sclavounos. 

The turbine, outfitted with stabilizers normally found in skyscrapers, would stand almost as tall as the Washington Monument, with rotors spanning the length of a football field.  Its five megawatt output would more than double that of a land-based windmill, and improve by almost half the production of standard shallow-water units, which sit on towers embedded in the ocean floor. 

Once in place, the windmill would be tested against the powerful waves, salt water and unforeseen circumstances of the real world.  Insights gleaned from the prototype's performance would make the first generation of floating wind farms lighter, cheaper and more reliable. 

Walt Musial, an offshore energy expert at the National Renewable Energy Laboratory, noted that traditional wind power costs fell from forty cents per kilowatt hour in the 1980s to just five cents per kilowatt hour today.  He believes offshore generation will follow a similar path, but cautioned against expecting too much too quickly.

"It's very difficult to do things at sea," said Musial.  "It's the right way to go, but it's not going to work the first time.  It's not going to be economical."  Musial said that new and expensive technologies must be developed before floating wind farms are technically feasible and competitively priced. 

Sclavounos hopes that energy companies, confronted by shrinking oil reserves and an environmentally aware public, will invest in his project, and is more optimistic than Musial in the immediate possibilities of offshore power. 

"It's not pie in the sky.  It's not that we've built something new and unproven.  The oil indsutry builds structures that float in severe weather all the time," Sclavounos said.  "The time from here to reality is more a matter of funding than taking significant technological risks."

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Posted on Sep 22, 2006 at 3:35 PM
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