Some look like trees. Others, a flight of birds. A new "flock" of turbines is coming, thanks to vertical axis technology.
There is no single design for these upended wind catchers, but all share one key aspect: the blades turn around an axis that points skyward. And unlike their horizontal brethren, the components and associated generators of a vertical turbine are placed at its base, giving it a lower center of gravity. Most are also relatively small, and unlike horizontal units, they can be grouped very closely together to optimize efficiency.
In many large cities, including New York, San Francisco, Boston and Chicago, city officials and scientists have been studying vertical axis turbines and contemplating their use. Paris has embraced the notion with enthusiasm, even allowing two giant turbines of this type to be installed within the steel latticework of the Eiffel Tower, which might someday generate enough electricity to power the ground floor of the tourist attraction. Some private firms worldwide have begun integrating vertical axis turbines into architectural plans for commercial buildings.
But vertical turbines have also attracted a sizable number of skeptics and naysayers.
“You can make a [vertical axis wind turbine] that will produce electricity,” says Robert Preus, a researcher at the National Renewable Energy Laboratory in Colorado who helped develop certification criteria for small wind turbines in the U.S. “The question is whether or not you can do so competitively.”