April 5, 2010 | 9
The problem with generating electricity by harnessing the wind is that it doesn’t always blow (though it may seem that way at times). And, typically, consumers remain intolerant of power interruptions.
But there may be a way to ensure a steady supply of wind, according to a new study in the April 5 Proceedings of the National Academy of Sciences. The key? Sea breezes (and a lot of expensive wiring).
Willett Kempton, director of the University of Delaware’s Center for Carbon-Free Power Integration, and his colleagues analyzed wind patterns from 11 sites on the U.S. East Coast, along the 2,500 kilometers from Maine to Florida. By wiring together hypothetical offshore wind turbines along this coastline, the researchers found that they could guarantee a steady supply of electricity. In fact, according to their model, there would never be a time when the wind wasn’t producing some electricity—and previous research by Kempton has shown that offshore wind power alone could supply the needs of coastal states.
Of course, no offshore wind turbines exist anywhere off the U.S. East Coast—and reactions from coastal residents have been as mercurial as the wind, depending on whether one resides in Cape Cod or Cape Hatteras—so this exercise remains entirely theoretical. As it stands, the roughly 2 gigawatts of offshore wind turbines proposed along the East Coast are largely planned to operate independently. And the longest (and most expensive) high-voltage direct current cable ever laid spans just 580 kilometers. The researchers estimate the cost of the cable alone for this plan at $1.4 billion (though that is only 15 percent of the cost of all the offshore wind turbine installations).
But should this abundant resource be tapped, a unified grid of offshore turbines could help make wind power reliable. After all, as Kempton et al. wrote: "There is almost always a pressure gradient somewhere, and cyclonic events move along the coast."
Image: Courtesy of Hans Hillewaert