Use it

4. Hydroelectric Power
•Hydro means "water". So, hydropower is "water
power" and hydroelectric power is electricity
generated using water power. Potential energy
(or the "stored" energy in a reservoir) becomes
kinetic (or moving energy). This is changed to
mechanical energy in a power plant, which is
then turned into electrical energy. Hydroelectric
power is a renewable resource.

5. Hydroelectric Power
• The damming of streams and rivers has been an
integral part of human civilization from its early
history. Controversy paralleled this use because
impounding and diverting water for upstream users
affects those who live downstream, and also modifies
the local habitats of plants and animals. Dams are
built to control floods, improve navigation, provide a
drinking-water supply, create or enhance recreational
opportunities, and provide water for irrigation and
other agricultural uses. A small percentage of re used
to generate power.

6. Components Of The Plant And Their
Role In Its Working
Functioning of a hydroelectric power plant
 Hydroelectricity is produced in a hydroelectric power
plant. In this plant, the water is released from a high
location. The potential energy present in the water is
converted into kinetic energy, which is then used to
rotate the blades of a turbine. The turbine is hooked to
the generator which produces electricity.

7. Components Of The Plant And Their Role
In Its Working
 Here are the basic components of a conventional
hydropower plant:

8. The main components of hydroelectric
power plant
• a) The reservoir: Water from a natural water body like
a river is stored in the reservoir. This reservoir is built at
a level higher than the turbine.
• b) The dam: The flow of water stored in the reservoir is
obstructed by huge walls of the dam. This prevents the
water from flowing and helps us harness the energy
present in it. The dam consists of gates present at its
bottom, which can be lifted to allow the flow of water
through them.

9. The main components of hydroelectric
power plant
• Most hydropower plants rely on a dam that holds back
water, creating a large reservoir.
• c) The penstock: This connects the reservoir with the
turbine propeller and runs in a downward inclined manner.
When the gates of the dam are lifted, the force of gravity
makes the water flow down the penstock and reach the
blades of the turbine. As the water flows through the
penstock, the potential energy of water stored in the dam is
converted into kinetic energy.
• d) The turbine: The kinetic energy of the running water
turns the blades of the turbine. The turbine can be either a
Pelton Wheel Model or a Centrifugal type. The turbine has
a shaft connected to the generator.

10. The main components of hydroelectric
power plant
• 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).
• e) The generator: A shaft runs from the turbine to the
generator. When the blades of the turbine rotate, the
shaft turns a motor which produces electric current in
the generator.

11. The main components of hydroelectric
power plant
 Giant magnets rotate past copper coils, producing
alternating current (AC) by moving electrons. (You'll
learn more about how the generator works later.)
 f) Power lines: The power produced in the generator
is sent to various power distribution stations through
the power lines.

12. The main components of hydroelectric
power plant
 The Generator
The heart of the hydroelectric power plant is the generator.
Most hydropower plants have several of these generators.

13. Environmental Impact and Drawbacks
• Large hydroelectric dams have a number of negative
impacts on the local environment and human society.
Dams disrupt river ecosystems and migrations, killing
aquatic life that gets caught in turbine blades. Dams
also create artificial reservoirs, which floods farmland
and forests, and displaces wildlife and people.
Hydroelectric projects are also susceptible to
fluctuations in river flows and rainfall. Ghana, which
depends on energy from the Volta River Dam, has
suffered severe energy shortages in recent years because
of lack of rainfall.

14. Environmental Impact and Drawbacks
 Large dams and reservoirs in tropical regions are
important sources of greenhouse gases. According to
Brazil's National Institute for Space Research (INPE),
each year the world's dams give off over 100 million
metric tons of methane. INPE scientists are developing
ways to produce energy by burning this methane.

15. Advantages of Hydroelectric Power
Production and Usage
 1. Hydroelectricity is a renewable energy source.
Hydroelectricity uses the energy of running water,
without reducing its quantity, to produce electricity.
Therefore, all hydroelectric developments, of small or
large size, whether run of the river or of accumulated
storage, fit the concept of renewable energy.

16. Advantages of Hydroelectric Power
Production and Usage
 4. Hydroelectricity contributes to the storage of
drinking water.
Hydroelectric power plant reservoirs collect
rainwater, which can then be used for consumption or
for irrigation. In storing water, they protect the water
tables against depletion and reduce our vulnerability
to floods and droughts.

17. Advantages of Hydroelectric Power
Production and Usage
• 9. Hydroelectricity means clean and cheap energy
for today and for tomorrow.
With an average lifetime of 50 to 100 years,
hydroelectric developments are long-term investments
that can benefit various generations. They can be
easily upgraded to incorporate more recent
technologies and have very low operating and
maintenance costs.

18. Hydropower and the Environment
 Hydropower is nonpolluting, but does have
environmental impacts
 Hydropower does not pollute the water or the air.
However, hydropower facilities can have large
environmental impacts by changing the environment
and affecting land use, homes, and natural habitats in
the dam area.