Power: Harnessing the wind: New schemes may provide solutions to the age-old problem of building efficient wind machines

Wind energy presents many advantages. It is clean, free, renewable, and domestically produced. And now, with the aid of modern technology, it could be used to a greater extent than ever before to offset U.S. dependence on imported oil. As much as 20 to 40 percent of the nation's total energy supply could be provided by wind-energy generating systems.