Hydroelectric Power Plant

1. HYDROELECTRIC POWER PLANT

2. Hydropower to Electric Power
Potential
Energy
Kinetic
Energy
Electrical
Energy
Mechanical
Energy
Electricity

3. Hydropower to Electric Power

4. How Hydropower Works
 Water from the reservoir
flows due to gravity to
drive the turbine.
 Turbine is connected to a
generator.
 Power generated is
transmitted over power
lines.

5. How Hydropower Works (2)
 A water turbine that cover the energy of flowing
or falling water into mechanical energy that
drives a generator, which generates electrical
power. This is a heart of hydropower power plant.
 A control mechanism to provide stable electrical
power. It is called governor.
 Electrical transmission line to deliver the power
to its destination.

6. Sizes of Hydropower Plants
 Pico hydroelectric plant
 Up to 10kW, remote areas away from the grid
 Micro hydroelectric plant
 Capacity 10kW to 300kW, usually provided power
for small community or rural industry in remote
areas away from the grid
 Small hydroelectric plant
 Capacity 300kW to 1MW
 Mini hydroelectric plant
 Capacity above 1MW
 Medium hydroelectric plant
 15 - 100 MW usually feeding a grid
 Large hydroelectric plant
 More than 100 MW feeding into a large electricity
grid

7. Micro Hydropower Systems
 Many rivers are permanent, they never
dry up, and these are the most suitable
for micro-hydro power production
 Micro hydro turbine could be a waterwheel
 Newer turbines : Pelton wheel (most
common)
 Others : Turgo, Crossflow and various
axial flow turbines

8. Turbine Classified

9. Impulse Turbines
 Uses the velocity of the water to move
the runner and discharges to atmospheric
pressure.
 The water stream hits each bucket on the
runner.
 High head, low flow applications.
 Types : Pelton turbine, Turgo turbine

10. Pelton Turbine

11. Turgo Turbine

12. Reaction Turbines
 Combined action of pressure and moving
water.
 Runner placed directly in the water stream
flowing over the blades rather than striking
each individually.
 Lower head and higher flows than
compared with the impulse turbines.

13. Francis Turbine

14. Kaplan Turbine

15. Chain Turbine
 It is a gravity machine
 It is built up of two
parallel chain systems
joint together at the
chains with a series of
buckets.
 The flow rater entering
the buckets is controlled
by the water valve
through a motor to open
or close the valve.
 Buckets fill full of water
go down to bring to rotary
sprocket system.

16. Governor
 To maintain the generator at a constant 50Hz
frequency, it is necessary to maintain the generator
shaft at a constant rotational speed.
 In the independent hydroelectric power plant, the
rotational speed of the micro hydro power generator
can be change when loads are added or subtracted
from the electrical system.
120
0 pN
f



17. Governor (2)
 The system frequency can be maintained constant by eliminating the
mismatch between generator and load.
 Governor is to receipt the frequency signal from the output of generator.
 And it is compared with standard frequency signal.
 From these results, governor output signal is coming-out to control the
valve of water at the entrance to the turbine.

19. Governor Discussion
 This governor effectively eliminate the
frequency deviations due to load
disturbances for different nominal
loadings of the system
 It is importance as the saved water can
be used for irrigation.

21. ADVANTAGES
1. Once a dam is constructed, electricity can
be produced at a constant rate.
2. If electricity is not needed, the sluice
gates can be shut, stopping electricity
generation. The water can be saved for
use another time when electricity demand
is high.
3. Dams are designed to last many decades
and so can contribute to the generation of
electricity for many years / decades.
.

22. 4. The lake that forms behind the dam can
be used for water sports and leisure /
pleasure activities. Often large dams
become tourist attractions in their own
right.
5. The lake's water can be used for
irrigation purposes.
6. The build up of water in the lake means
that energy can be stored until needed,
when the water is released to produce
electricity.
7. When in use, electricity produced by dam
systems do not produce green house
gases. They do not pollute the atmosphere

23. DISADVANATGES:
1. Dams are extremely expensive to build and
must be built to a very high standard.
2. The high cost of dam construction means that
they must operate for many decades to become
profitable.
3. The flooding of large areas of land means that
the natural environment is destroyed.
4. People living in villages and towns that are in
the valley to be flooded, must move out. This
means that they lose their farms and businesses.
In some countries, people are forcibly removed
so that hydro-power schemes can go ahead.

24. 5. The building of large dams can cause
serious geological damage.
6. Dams built blocking the progress of a
river in one country usually means that
the water supply from the same river in
the following country is out of their
control. This can lead to serious problems
between neighbouring countries.
7. Building a large dam alters the natural
water table level