[ti:Bladeless Wind Generator Safe for Birds]
[ar:Jonathan Evans]
[al:Science in The News]
[by:www.21voa.com]
[00:00.00]Wind turbines are tall structures with large blades used to produce electricity. 
[00:06.75]They are useful sources of low-cost, renewable energy. 
[00:11.59]But they can also be deadly to birds and bats. 
[00:16.47]The turbines' large blades turn quickly in the sky. 
[00:21.79]Birds and bats sometimes fly into them and are killed.
[00:27.44]But a new type of wind generator may offer an answer to that problem.
[00:33.31]In 2002, Spanish inventor David Yanez saw a short film 
[00:39.63]about the Tacoma Narrows Bridge in the U.S. 
[00:43.58]Strong winds caused the bridge to collapse in 1940. 
[00:49.57]That incident was an example of the powerful vibrations wind 
[00:54.81]can create when it blows past a long pole, 
[00:58.18]like a car antenna or a stick of light wood. 
[01:01.52]It gave Mr. Yanez the idea for a new type of wind-energy generator. 
[01:06.77]He said he wanted it to include all the desired qualities.
[01:11.50]He said it should be as low-cost as possible 
[01:14.89]and need as little maintenance as possible. 
[01:17.94]He also said he wanted it to quick to set up.
[01:22.06]Mr. Yanez and his friend Raoul Martin 
[01:25.74]took the idea to an engineering business. 
[01:28.71]But they were told their idea would never work. 
[01:32.20]So, Mr. Yanez and Mr. Martin built a small wind tunnel 
[01:37.62]to experiment on their own.
[01:39.59]They built a large working model of the generator 
[01:43.03]in a field near their workspace. 
[01:45.43]They called the equipment Vortex.
[01:47.93]Mr. Yanez described how the Vortex generator works.
[01:52.78]He said there is a mast that serves like a blade on turbines. 
[01:59.48]It is made from the same material as other generators. 
[02:02.92]Wind causes the mast to oscillate, or move back and forth. 
[02:07.46]It does not spin around. So it creates no risk to birds and bats.
[02:12.62]The Vortex generator creates about 30 percent 
[02:16.87]less energy than a wind turbine with blades. 
[02:20.25]But it is lighter and less costly to build and maintain. 
[02:24.60]It is made mostly of plastic and has very few moving parts. 
[02:30.29]The generator also does not create noise.
[02:34.21]The current prototype works at wind speeds 
[02:37.41]ranging from 1.5 to 7 meters per second.
[02:41.66]The inventors say the next step is building a 12.5-meter-tall bladeless generator 
[02:48.51]that could power small businesses or individual homes. 
[02:53.12]They add that the generator could also provide additional power 
[02:57.55]to a larger power supply system.
[03:00.03]Mr. Yanez expects the Vortex bladeless generator 
[03:03.90]to be ready for general sale by 2017.
[03:07.77]I'm Jonathan Evans.
[03:10.04]Words in this Story
[03:12.72]blade 每 n. a flat long turning part 
[03:17.01]that is used on some machines to push air or water
[03:20.99]generator 每 n. a machine that produces electricity
[03:26.26]vibration 每 n. a continuous slight shaking movement : a series of small, 
[03:33.20]fast movements back and forth or from side to side
[03:36.79]maintenance 每 n. the act of keeping property or equipment in good condition 
[03:43.39]by making repairs, correcting problems, etc.
[03:47.52]mast 每 n. a tall pole that supports or holds something
[03:53.34]oscillate 每 v. to move in one direction and then back again many times
[03:59.64]prototype 每 n. an original or first model of something from 
[04:05.56]which other forms are copied or developed
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