Tuesday, October 11, 2005

Highly Focused Wind

Wind power is one of the most competitive alternative energy technologies, but it suffers from two important drawbacks: The air currents powering wind turbines are much less reliable than the rivers tapped by hydroelectric dams. They are also sufficiently diffuse to require a large number of turbines, dispersed across a wide area, to generate as much electricity as a coal- or gas-fired power plant. Cyclones and hurricanes clearly pack a lot of power, but they are unpredictable and uncontrollable. Now someone has come up with a novel way of overcoming both of these limitations at once: artificial tornadoes.

Tell me this doesn't sound like something out of a 1950s sci-fi movie: you use solar power and steam to spin up your own storm, contained within a high circular wall and driving a set of turbines hard enough to generate 200 megawatts of power. An extension of the solar chimney concept, the whole thing sounds a bit nutty, but not nutty enough to keep it from being picked up by a prestigious international journal like The Economist.

Granted, this idea is a long way from becoming a practical reality. It's got at least as many public relations problems as the flying windmills I mentioned earlier this year. Despite that, though, it represents precisely the kind of thinking we need more of just now. Meeting our long-term future energy needs while reducing our dependence on fossil fuels leads us inexorably down one of two broad avenues: creating our own highly concentrated energy sources using nuclear fission or fusion, and finding ways to tap the densest energy flows in our environment, including ocean currents, high-velocity winds, dry-rock geothermal energy, or sunlight above the earth's atmosphere. We are swimming in energy; tapping it effectively is the trick.

That doesn't mean that low-density sources such as photovoltaics and conventional wind turbines won't be important contributors along the way, but they simply can't displace the 86% of global primary energy supplied by coal, oil and natural gas, without some serious help from something a lot more concentrated. Are pocket storms the answer? Unlikely. But could something come out of this initiative that, when combined with other concepts, unlocks a new, practical high-energy-density source? I wouldn't discount the possibility.

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