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标题: Using Water to Produce Electricity [打印本页]

作者: 李武军    时间: 2011-6-29 10:19     标题: Using Water to Produce Electricity

[audio]http://www.51voa.com/path.asp?url=/voasp/special200405040041.mp3[/audio]

This is the VOA Special English Agriculture Report.
The power of flowing water can be used to produce electricity. This can be done anywhere there is water and a hill for it to flow down rapidly.
Micro-hydro systems produce electric power from water. These small water-powered systems can produce up to fifteen kilowatts of electrical power. This is enough to provide electricity for a village of fifty to eighty houses to use to power lights and small motors. It does not provide enough power for industrial uses. Micro-hydro systems are important for villages that are near water and do not have electric power.
Before you begin the project, you should make sure that people living near you approve. People protest if there is less water for them to use for their crops or for washing clothes.
Building or buying a micro-hydro system requires planning. First, someone has to estimate the amount of electrical power the falling water can produce. It is a complex process. It is necessary to find out how far the water drops and to measure the amount of water that flows past an area each second. These numbers can show how much electrical power can be produced. Then you can buy or build a micro-hydro system of the right size.
Next you need to decide if falling water needs to flow inside a pipe or can flow freely. A long pipe costs more, but the water is easier to control. Even if the water flows freely, it must enter a piece of pipe just before it flows into a machine called a turbine. The water flowing through the pipe turns a large wheel in the turbine around. The turbine sends the power to a generator that creates electricity.
Heavy rain can cause a problem for a micro-hydro system. The rain carries grass, leaves and other material into waterways. This can cause the turbine to stop turning. The problem can be prevented by placing steel bars in the pipe before the water flows into the turbine. These steel bars catch the material before it can damage the machine.
People who can use flowing water to produce electricity have a free supply of energy. You can get more information about projects like this from the group Volunteers in Technical Assistance. VITA is on the Internet at vita.org.
This VOA Special English Agriculture Report was written by Gary Garriott.





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