The energy in the flowing water can be used to produce
electricity. Waves result from the interaction of the wind with the
surface of the sea and represent a transfer of energy from the wind
to the sea. Energy can be extracted from tides by creating a
reservoir or basin behind a barrage and then passing tidal waters
through turbines in the barrage to generate electricity.
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Slide 5
Although most energy in a country is produced by fossil-fuel
and nuclear power plants, hydroelectricity is still important to
the Nation, as about 7 percent of total power is produced by
hydroelectric plants. Nowadays, huge power generators are placed
inside the dams. Water flowing through the dams spin turbine blades
which are connected to generators. Power is produced and is sent to
homes and businesses.
Slide 6
Mostly, the fast moving water (kinetic energy) strikes the
turbines and they start moving (mechanical energy) and then this
energy is used to run electric generators. The transference of
energy takes place from one form to another. Now instead of water
wheels water falling from a vertical height is used which has
stored potential energy in it due to its position and the water is
then passed through the gate or vessels which take the water to the
turbines which convert potential energy into mechanical energy,
these vessels are called penstocks.
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Slide 8
Slide 9
The dam is made on a river to collect water. Whenever it rains,
the water is collected into the dam so it serves as a water
reservoir. The potential energy for further work is generated by
the water level difference between the dams and the turbines
because the water level in the dams is very high. Dams also control
the water flow through penstocks.
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Slide 11
The next step is to convert this kinetic energy of water into
mechanical energy. The water flows from a height throw the
penstocks which are the channeled vessels to the turbines which
have blades. The falling water has enough kinetic energy that when
they strike hard with the blades of the turbines, they start
spinning which means that the kinetic energy is converted into
mechanical energy. The turbines resemble a lot with the windmills
in which wind energy is used instead of water. But the turbines use
potential and mechanical energy of falling water to convert into
work.
Slide 12
The shafts of the turbines convert the mechanical energy into
electric energy. Basically, the generators work on the principle of
magnets which is that when you pass a magnet near a conductor,
electric current flows through it.
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Slide 14
The rotor having field pole rotates on a specific speed. When
it rotates it passes the field poles across the stator to make sure
that it has the same effect of electric field. The water should
keep on moving constantly to make sure that the amount of
electricity produced is great. Static water cannot generate
electricity.
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Slide 16
The electricity via power lines is transferred to substation
which provides it to the consumers. So, the process is of great
importance. It should be performed in a right manner to ensure the
great production of electricity. This process is not much costly as
no fuels are produced and not much health hazardous chemicals are
produced by it. But the research is still going on.
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Slide 18
As the water flows into the reservoir from catchment area, the
kinetic energy of flowing water changes to potential energy. When
the water from the reservoir falls into the intake, the
gravitational potential energy stored in the water is converted
into kinetic energy. As the water flowing at a high speed strikes
the blades of the turbine its kinetic energy changes to rational
kinetic energy of the turbine. As the turbine is coupled to the
shaft of generator, the rotational kinetic energy of turbines
changes to rotational kinetic energy of armature. As the coils of
armature rotate in magnetic field, the rotational kinetic energy of
armature changes to the electric energy in its coils.
Slide 19
The water required for generating Hydroelectric powers
available free of cost. Hydroelectric power stations are pollution
free. Compared to among others fossil fuels and nuclear energy,
hydroelectricity is much safer. There is no fuel involved.
Slide 20
For running a hydroelectric power station throughout the year,
a vast amount of water is required. This demands a vast reservoir.
Such a reservoir can be made only at a few places which are
geographically suitable and do not interfere with eco-system and
human habitation. The minimum height required to convert the stored
potential energy of water into electric energy is 34m. Between the
turbine and free surface of water in reservoir. This involves
massive investment on the construction of dams.