Wind turbines may be one of the best renewable energy solutions, but as turbines get larger they also get noisier, become more of an eyesore, and require increasingly larger expanses of land. One solution: ocean-based wind turbines.
While offshore turbines already have been constructed, they've traditionally been situated in shallow waters, where the tower extends directly into the seabed. That restricts the turbines to near-shore waters with depths no greater than 50 meters -- and precludes their use in deeper waters, where winds generally gust at higher speeds.
An alternative is placing turbines on floating platforms, says naval architect Dominique Roddier of Berkeley, California-based Marine Innovation & Technology. He and his and colleagues have published a feasibility study of one platform design -- dubbed "WindFloat" -- in the latest issue of the Journal of Renewable and Sustainable Energy, which is published by the American Institute of Physics (AIP).
By testing a 1:65 scale model in a wave tank, the researchers show that the three-legged floating platform, which is based on existing gas and oil offshore platform designs, is stable enough to support a 5-megawatt wind turbine, the largest turbine that currently exists. These mammoth turbines are 70 meters tall and have rotors the size of a football field. Just one, Roddier says, produces enough energy "to support a small town."
The next step, says Roddier, is building a prototype to understand the life-cycle cost of such projects and to refine the economics models. The prototype, which is being built in collaboration with electricity operator Energias de Portugal, "should be in the water by the end of summer 2012," he says.
The Journal of Applied Physics is the American Institute of Physics' (AIP) archival journal for significant new results in applied physics; content is published online daily, collected into two online and printed issues per month (24 issues per year). The journal publishes articles that emphasize understanding of the physics underlying modern technology, but distinguished from technology on the one side and pure physics on the other. See: http://jap.aip.org/
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.
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The article, " Windfloat: a Floating Foundation for Offshore Wind Turbines" by Dominique Roddier et al will appear in the Journal of Renewable and Sustainable Energy. See: http://jrse.aip.org/