Site selection, Classification of hydroelectric power station, Construction, Environmental issues

1. HYDRO POWER PLANT
Presented By:SuryaPrakash N (161EE523)
Bannari Amman Institute of Technology,
Sathyamangalam, Erode, Tamil Nadu, India
Saturday, March 17,
2018
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2. Contents
 Site selection
 Classification of hydroelectric power
station
 Construction
Environmental issues
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2018
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3. Define Hydro-electric
Power Station
A generating station which utilises the
potential energy of water at a high level
for the generation of electrical energy is
known as a hydro-electric power station.
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2018
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4. Selection of Site
Availability of water
Water storage
Cost and type of land
Transportation facilities.
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5. Availability of water
 Availability of huge quantity of water,
such plants should be built at a place
(e.g.,river,canal) Enough water is
available at a good head.
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2018
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6. Storage of water
 Wide variations in water supply from a river or canal
during the year. To store water by constructing a dam
in order to ensure the generation of power
throughout the year.
 The storage helps in equalising the flow of water so
that any excess quantity of water at a certain period
of the year can be made available during times of
very low flow in the river Enough facilities for
erecting a dam and storage of water.
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2018
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7. Cost and type of land
 The land for the construction of the
plant should be available at a reasonable
price.
 Further, the bearing capacity of the
ground should be Enough to withstand
the weight of heavy equipment to be
installed.
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2018
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8. Transportation facilities
 The site selected for a hydro-electric
plant should be accessible by rail and
road so that necessary equipment and
machinery could be easily transported.
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9. Schematic Arrangement of
Hydro-electric Power Station
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10. Reservoir
 A reservoir is employed to store water which
is further utilized to generate power by
running the hydroelectric turbines.
 Catchment area gets its water from rain and
streams.
 The level of water surface in the reservoir is
called Head water level.
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2018
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11. Pressure tunnel
 It is a passage that carries water from the reservoir
to the surge tank.
Inlet valve
 Water from the penstock flows to the turbine
through the inlet valve. The valve may be partially
closed or open there by regulating the pressure of
water flowing to the turbine.
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2018
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12. Surge Tank
 When there is a sudden close or decrease in
pressure due to control valve then there is a
back flow of water. This creates a high pressure
zone in the penstock due to which it may burst .
This effect is known as WATER HAMMERING
EFFECT .
 To avoid this a tank is attached to the penstock
which stores water in it . This tank is called as
Surge Tank.Saturday, March 17,
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13. Surge Tank
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14. Penstock
 Penstock is the connecting pipe between the dam & the
turbine house.
 Low pressure penstock may be a canal a steel pipe.
 High pressure penstock consists of thick steel pipe.
 Each turbine separate penstock.
 Small size plants have penstocks of concrete.
 The water in the penstock possesses kinetic energy
due to its motion and potential energy due to its
height.
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15. Turbine & Generator
• Turbine & Generator is the most important part of any power
plant
• This combination is known as THE HEART OF THE POWER
PLANT.
• TURBINE :- Turbine is a very light fan like structure having
many number’s of blades . It has an ability to rotate on its axis
when water passes through it.
• GENERATOR :- Generator is a device in which when there is
rotation of coil between the strong Magnetic Field then it
produces an Alternating Current.
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16. Electrical equipments
 The electrical equipment of a hydro-electric power
station includes alternators, transformers, circuit
breakers and other switching and protective devices.
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17. Working
catchments area to turbine house
 Initially the water of the river is in Catchments Area.
 From catchments area the water flows to the dam.
 At the dam the water gets accumulated . Thus the potential
energy of the water increases due to the height of the dam .
 When the gates of the dam are opened then the water moves
with high Kinetic Energy into the penstock.
 Through the penstock water goes to the turbine house.
 Since the penstock makes water to flow from high altitude to
low altitude, Thus the Kinetic Energy of the water is again
raised.Saturday, March 17,
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18. turbine house to power house
• In the turbine house the pressure of the water is controlled by
the controlling valves as per the requirements.
• The controlled pressurized water is fed to the turbine.
• Due to the pressure of the water the light weight turbine
rotates.
• Due to the high speed rotation of the turbine the shaft
connected between the turbine and the generator rotates .
• Due to the rotation of generator the ac current is produced.
• This current is supplied to the powerhouse .
• From powerhouse it is supplied for the commercial purposes.
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19. Classification of hydroelectric power
station
 Classification on head.
 High head plant ( > 300 m.)
 Medium head plant. (60m to 300 m.)
 Low head plant. ( < 60m.)
 Classification on water condition
 Flaw of water plant.
 Storage of water plant.
 Pump storage water plant.
 Classification on operation.
 Manual plant.
 Automatic plant.
 Classification on type of load.
 Base load plant.
 Peak load plant.
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2018
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20. Advantages
(i) no fuel as water is used for the generation of electrical energy.
(ii) neat and clean as no smoke or ash is produced.
(iii) very small running charges because water is the source of
energy which is available free of cost.
(iv) simple in construction and requires less maintenance.
(v) not require a long starting time like a steam power station. In
fact, such plants can be put into service instantly.
(vi) It is robust and has a longer life.
(vii) Such plants serve many purposes. In addition to the generation
of electrical energy, they also help in irrigation and controlling
floods.
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2018
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21. Disadvantages
(i) It involves high capital cost due to construction of dam.
(ii) There is uncertainty about the availability of huge amount
of water due to dependence on weather conditions.
(iii) Skilled and experienced hands are required to build the
plant.
(iv) It requires high cost of transmission lines as the plant is
located in hilly areas which are quite away from the
consumers.
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2018
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22. Environmental Issues
• Land use – inundation and displacement of people
• Impacts on natural hydrology
• Altering river flows and natural flooding cycles
• fish, plants,
• Water chemistry changes
• Bacterial and viral infections
• Structural dam failure risks
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