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Kinetic Hydropower
» Conventional
Hydropower
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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 .
- 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.
- 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.
- 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.
- Outflow - Used water is carried through pipelines, called tailraces , and re-enters the river downstream.
The water in the reservoir is considered stored energy . When the gates open, the water flowing through the penstock becomes kinetic energy because it's in motion.
The generator, as you might have guessed, generates the electricity.
The basic process of generating electricity in this manner is
to rotate a series of magnets inside coils of wire. This process
moves electrons, which produces electrical current.
Each generator is made of certain basic parts:
- Shaft
- Excitor
- Rotor
- Stator
As the turbine turns, the excitor sends an electrical current
to the rotor. The rotor is a series of large electromagnets that
spins inside a tightly-wound coil of copper wire, called the stator.
The magnetic field between the coil and the magnets creates an
electric current.
Hydropower plants take advantage of a naturally occurring, continuous
process -- the process that causes rain to fall and rivers to
rise
The hydrologic cycle is important to hydropower plants because
they depend on water flow. If there is a lack of rain near the
plant, water won't collect upstream. With no water collecting
up stream, less water flows through the hydropower plant and less
electricity is generated.
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