How Hydropower Plants Work (Bahasa Inggris Teknik)

How Hydropower Plants Work (Bahasa Inggris Teknik)

   11:06 AM       Unknown

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The Power of Water

 

When watching a river roll by, it's hard to imagine the force it's carrying. If you have ever been white-water rafting, then you've felt a small part of the river's power. White-water rapids are created as a river, carrying a large amount of water downhill, bottlenecks through a narrow passageway. As the river is forced through this opening, its flow quickens. Floods are another example of how much force a tremendous volume of water can have. 

Hydropower plants harness water's energy and use simple mechanics to convert that energy into electricity. Hydropower plants are actually based on a rather simple concept -- water flowing through a dam turns a turbine, which turns a generator.

Here are the basic components of a conventional hydropower plant: 

• Dam - Most hydropower plants rely on a dam that holds back water, creating a large reservoir. Often, this reservoir is used as a recreational lake, such as Lake Roosevelt at the Grand Coulee Dam in Washington State.
• Intake - Gates on the dam open and gravity pulls the water through the penstock, a pipeline that leads to the turbine. Water builds up pressure as it flows through this pipe.
• Turbine - The water strikes and turns the large blades of a turbine, which is attached to a generator above it by way of a shaft. The most common type of turbine for hydropower plants is the Francis Turbine, which looks like a big disc with curved blades. A turbine can weigh as much as 172 tons and turn at a rate of 90 revolutions per minute (rpm), according to the Foundation for Water & Energy Education (FWEE).
• Generators - As the turbine blades turn, so do a series of magnets inside the generator. Giant magnets rotate past copper coils, producing alternating current (AC) by moving electrons. (You'll learn more about how the generator works later.)
• Transformer - The transformer inside the powerhouse takes the AC and converts it to higher-voltage current.
• Power lines - Out of every power plant come four wires: the three phases of power being produced simultaneously plus a neutral or ground common to all three. (Read How Power Distribution Grids Work to learn more about power line transmission.)
• Outflow - Used water is carried through pipelines, called tailraces, and re-enters the river downstream.

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