StatoilHydro, the Norwegian oil company, spent $60 million dollars to design and construct Hywind's tower and platform which rises almost 200 feet feet above the waves. The turbine sits atop a floating steel structure that extends 300 feet below the surface, is filled with ballast of water and rocks and is anchored to the ocean floor by three cables.
Here's a video on Hywind produced just before the 2.3 megawatt turbine went on line.
It's a very positive sign for the wind industry for many reasons. The winds blow stronger and more steadily offshore, and there are a host of siting advantages that floating wind farms will enjoy. One, for example, is that they can be positioned near load centers in deep water (much of the western coast of the United States will thus be open to floating wind farms). Another reason: They can be positioned beyond the horizon (approximately 12 miles out), where spinning turbines will no longer be visible, thus eliminating the "not in my backyard" ( NIMBY) problem. The siting of floating wind farms will also more readily accommodate local concerns about fishing and shipping lanes.
The east coast of the United States would likely be the first place that floating wind turbines would be installed. The wind resource is well-known there (it's been estimated that 300,000 megawatts of wind power are blowing off the mid-Atlantic coast), where off shore developers are already making headway in Delaware, New Jersey, Maryland, and Rhode Island. An undersea high voltage cable system, moreover, could link these offshore wind farms together and be used to ship power regionally. One developer in Europe, Eddie O'Connor, has been working on such an undersea high density transmission system, HVDC, which uses DC current to connect offshore wind farms across huge distances and thus eliminate the problem of intermittent power.
But, as StatoilHydro's Bratland observes, such a vision, if it is to occur, won't happen for another five to 10 years. "I'm more optimistic than I was two years ago," says Bratland, "but the supply chain must follow." By which Bratland means that wind turbine component manufacturers must decide to build the parts that will make the bigger, longer lasting turbines of the future.
Mark Svenvold, author of Big Weather: Chasing Tornadoes in the Heart of America, teaches at Seton Hall University, in South Orange, New Jersey.