VOA常速英语:Bird-friendly Bladeless Wind Turbine Mimics Nature

Energy created by conventional three-blade wind turbines is cheap, sustainable and pollution-free. But according to current estimates, the devices' fast-moving blades kill up to 300,000 birds annually in the U.S.

That could change with a bladeless wind converter called Saphonian, designed by Tunisian engineer Anis Aouni. He studied ancient sailboats and the movements of birds and fish to develop a parabolic dish that rotates in a peculiar pattern while catching the wind like a ship’s sail.

“It's like a big 'eight' in space," Aouni said. "It's a movement that we can find in nature. ... We find the same movement in fish tails when they are moving, or in birds' wings.”

The bladeless converter creates less noise than traditional wind turbines and does not suffer from the gyroscopic effect, which makes it easier to adjust to changes in wind direction. The prototype is a little more than 1 meter in diameter, but computer models show it is scalable to bigger sizes.

Aouni hopes it eventually will be able to turn 80 percent of wind energy into electricity.

“In practice, we reached 1.7 times the performance of a traditional wind turbine," he said. "Economically, it is a machine that costs much less than an equivalent wind turbine.”

Tunisian company Saphon Energy, which developed the prototype, has won several awards for the new turbine, including support from Microsoft’s initiative to help African startup companies.