HYDRO POWER PLANT

1. K.Sumalatha
Assistant professor
EEE department
KUCE&T
KU

2. Electricity by definition is electric current that is used as a power source!
This electric current is generated in a power plant, and then sent out
over a power grid to your homes, and ultimately to your power outlets.

3. GENERATION STATION
Bulk electrical power is produced by special plants known as
generating station (or) power plants.
To provide cheap, reliable and continous service
Importance of electrical energy
1.Convenient form
Ex. heater
bulb
motor
2.Easy control
3.Greater flexibility

4. Hydro Power PowerHydro Power Power

5. Definition of A Turbo MachineDefinition of A Turbo Machine
Turbines are energy developing machines. Turbines convert fluid energy intoTurbines are energy developing machines. Turbines convert fluid energy into
mechanical energy. The mechanical energy developed by the turbines is usedmechanical energy. The mechanical energy developed by the turbines is used
in running an electric generator, which is directly connected, to the shaft of thein running an electric generator, which is directly connected, to the shaft of the
electrical generator.electrical generator.
Earlier days method – wooden wheelEarlier days method – wooden wheel
Overshot WheelOvershot Wheel
 Had very good efficiency
 Could not handle large quantity of water
Undershot Wheel
 Low Efficiency

6. Hydropower to Electric PowerHydropower to Electric Power

7. Selection of siteSelection of site
• Location of Dam
• Choice of Dam
• Quantity of water available
• Accessibility of site (cost &type of land)
• Distance from the load center

8. Classification based on contractionClassification based on contraction
• Runoff river plant without pondage
 dam across river
 low head
 low capacity
• Runoff river plant with pondage
• Valley dam plant
 large storage capacity
 Power plant is located at toe of the dam
• Diversion canal plant
• High Diversion canal plant

9. Sizes of Hydropower PlantsSizes of Hydropower Plants
• Definitions may vary.
• Large plants : capacity >30 MW
• Small Plants : capacity b/w 100 kW to 30 MW
• Micro Plants : capacity up to 100 kW

10. How Hydropower Works!How Hydropower Works!
• Hydrologic cycle

11. How Hydropower Works! (ctd…)How Hydropower Works! (ctd…)
• 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.

12. Hydropower to Electric PowerHydropower to Electric Power
Potential
Energy
Kinetic
Energy
Electrical
Energy
Mechanical
Energy
Electricity

13. How Hydropower WorksHow 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.

14. General layout of Hydro-Power PlantGeneral layout of Hydro-Power Plant

15. General layout of Hydro-Power PlantGeneral layout of Hydro-Power Plant
a) Reservoir
Reservoirs ensure supply of water through out the year, by storing water
during rainy season and supplying the same during dry season.
b) Damb) Dam
The function of the dam is to increase the reservoir capacity and to increaseThe function of the dam is to increase the reservoir capacity and to increase
the working head of the turbine.the working head of the turbine.
c) Penstockc) Penstock
A pipe between dam and turbine is known as penstock. It will carry the waterA pipe between dam and turbine is known as penstock. It will carry the water
from dam to turbine. Penstock is commonly made of steel pipes covered withfrom dam to turbine. Penstock is commonly made of steel pipes covered with
RCC.RCC.

16. d) Surge tank/Forebayd) Surge tank/Forebay
When the rate of water flow through the penstock is suddenly decreased, theWhen the rate of water flow through the penstock is suddenly decreased, the
pressure inside the penstock will increase suddenly due to water hammerpressure inside the penstock will increase suddenly due to water hammer
and thereby damage the penstock.and thereby damage the penstock.
Surge tank/Forebay is constructed between the dam and turbine. It will actSurge tank/Forebay is constructed between the dam and turbine. It will act
as a pressure regulator during variable loads.as a pressure regulator during variable loads.
e) Turbinee) Turbine
Turbines convert the kinetic and potential energy of water into mechanicalTurbines convert the kinetic and potential energy of water into mechanical
energy to produce electric power.energy to produce electric power.
f) Generator and Transformer f) Generator and Transformer
Electric generator converts mechanical energy into electrical energy. A stepElectric generator converts mechanical energy into electrical energy. A step
up transformer will increase the voltage for loss free transmission.up transformer will increase the voltage for loss free transmission.

17. Advantages of hydraulic power plants
 Operating cost is very low
 Less Maintenance cost and less manpower required
 Pollution free
 Quick to start and easy to synchronize
 Can be used for irrigation and flood control
 Long plant life.
Disadvantages of Hydraulic Power Plants
 Initial cost of total plant is comparatively high
 Power generation depends on availability of water
 Cost of transmission is high since most of the plants are in remote areas
 Project duration is long.
Advantages and Disadvantages of HPPAdvantages and Disadvantages of HPP

18. 1) Hydraulic Efficiency – due to hydraulic losses
Power developed by the runner
Net power supplied at the turbine entrance
SI Unit: kW
Metric Unit : Horse Power/Water Horse Power (W.H.P)
2) Mechanical Efficiency – Due to mechanical losses ( bearing friction)
Power available at the turbine shaft (P)
Power developed by the runner
Efficiencies of Hydraulic TurbinesEfficiencies of Hydraulic Turbines

19. 3) Volumetric Efficiency – due to amt of water slips directly to the tail race
Amount of water striking the runner
Amount of water supplied to the turbine
4) Overall Efficiency
Power available at the turbine shaft (P)
Net power supplied at the turbine entrance
Cont…Cont…

20. Classification of TurbinesClassification of Turbines
Turbines are classified according to several considerations as indicated below.Turbines are classified according to several considerations as indicated below.
i) Based on working principlei) Based on working principle
a) Impulse turbinea) Impulse turbine
b) Reaction turbineb) Reaction turbine

21. Impulse Turbine: (pressure less)
The pressure of liquid does not change while flowing through the rotor of the
machine. In Impulse Turbines pressure change occur only in the nozzles
of the machine.
One such example of impulse turbine is Pelton Wheel.
Reaction Turbine:
The pressure of liquid changes while it flows through the rotor of the
machine. The change in fluid velocity and reduction in its pressure causes
a reaction on the turbine blades; this is where from the name Reaction
Turbine may have been derived.
Francis and Kaplan Turbines fall in the category of Reaction Turbines.
Cont…Cont…

22. Cont…Cont…
ii) Based on working mediaii) Based on working media
a) Hydraulic turbinea) Hydraulic turbine
b) Steam turbineb) Steam turbine
c) Gas turbinec) Gas turbine
d) Wind Turbined) Wind Turbine
iii) Based on headiii) Based on head
Head is the elevation difference of reservoir water level and D/S water level.Head is the elevation difference of reservoir water level and D/S water level.
a) Very High head turbinea) Very High head turbine (500 m &above)(500 m &above) Pelton TurbinePelton Turbine
b) High head turbineb) High head turbine ( 70-500 m)( 70-500 m) Francis Turbine (or )PeltonFrancis Turbine (or )Pelton
b) Medium head turbineb) Medium head turbine (15– 70 m)(15– 70 m) Kaplan (or)Kaplan (or) Francis TurbineFrancis Turbine
c) Low head turbinec) Low head turbine (Below 60 m)(Below 60 m) Kaplan TurbineKaplan Turbine

23. iv) Based on specific speediv) Based on specific speed
Turbines can be classified based on Specific Speed. Specific speed is definedTurbines can be classified based on Specific Speed. Specific speed is defined
as the speed in rpm of a geometrically similar turbine, which is identical inas the speed in rpm of a geometrically similar turbine, which is identical in
shape, dimensions, blade angles and gate openings with the actual turbineshape, dimensions, blade angles and gate openings with the actual turbine
working under unit head and developing unit power. Specific speed is used toworking under unit head and developing unit power. Specific speed is used to
compare the turbines and is denoted by Ns.compare the turbines and is denoted by Ns.
Specific speedSpecific speed Ns = N √P / H5/4
a) Low specific speeda) Low specific speed (8.5 – 30)(8.5 – 30) - Pelton Turbine- Pelton Turbine
b) Medium specific speed (50 – 340)b) Medium specific speed (50 – 340) - Francis Turbine- Francis Turbine
c) High specific speedc) High specific speed (255 – 860)(255 – 860) - Kaplan Turbine- Kaplan Turbine
Cont…Cont…

24. v) Based on disposition of turbine main shaftv) Based on disposition of turbine main shaft
a) Horizontal shafta) Horizontal shaft
b) Vertical shaftb) Vertical shaft
vi) Based on flow through the runnervi) Based on flow through the runner
a) Radial flowa) Radial flow
1. Inward1. Inward
2. Outward2. Outward
b) Axial flowb) Axial flow - Kaplan Turbine- Kaplan Turbine
c) Mixed flowc) Mixed flow - Francis Turbine- Francis Turbine
d) Tangential flowd) Tangential flow - Pelton Turbine- Pelton Turbine
Cont…Cont…

25. Pelton Wheel TurbinePelton Wheel Turbine
Design of Pelton Wheel Turbine
 It has a circular disk with cup shaped blades/buckets,
 Water jet emerging from a nozzle is tangential to the circumference of the
wheel.

26. Impulse TurbinesImpulse 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

27. Pelton TurbinePelton Turbine

28. Turgo TurbineTurgo Turbine

29. ReactionReaction
TurbinesTurbines
• 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.

30. Working Principle of Pelton Turbine
 Water jets emerging strike the buckets at splitter.
 Stream flow along the inner curve of the bucket and leave it in the direction
opposite to that of incoming jet.
 The high pressure water can be obtained from any water body situated at
some height or streams of water flowing down the hills.
 The change in momentum (direction as well as speed) of water stream
produces an impulse on the blades of the wheel of Pelton Turbine. This
impulse generates the torque and rotation in the shaft of Pelton Turbine.
 Horizontal shaft - Not more than 2 jets are used and
Vertical shaft - Larger no. of jets (upto 6) are used.
 Iron/Steel casing to prevent splashing of water and to lead water to the tail
race.

31. Classification based on contractionClassification based on contraction
• Runoff river plant without pondage
 dam across river
 low head
 low capacity
• Runoff river plant with pondage
• Valley dam plant
 large storage capacity
 Power plant is located at toe of the dam
• Diversion canal plant
• High Diversion canal plant

32. TECHNOLOGYTECHNOLOGY

33. TechnologyTechnology
Hydropower
Technology
Impoundment Diversion
Pumped
Storage

34. Impoundment facilityImpoundment facility

35. Dam TypesDam Types
• Arch
• Gravity
• Buttress
• Embankment or Earth

36. Arch DamsArch Dams
• Arch shape gives
strength
• Less material (cheaper)
• Narrow sites
• Need strong abutments

37. Concrete Gravity DamsConcrete Gravity Dams
• Weight holds dam in
place
• Lots of concrete
(expensive)

38. Buttress DamsButtress Dams
• Face is held up by a
series of supports
• Flat or curved face

39. Dams ConstructionDams Construction

40. Diversion FacilityDiversion Facility
• Doesn’t require dam
• Facility channels portion
of river through canal or
penstock

41. PumpedPumped
StorageStorage
• During Storage, water
pumped from lower
reservoir to higher one.
• Water released back to
lower reservoir to
generate electricity.

42. Pumped StoragePumped Storage
• Operation : Two pools of Water
• Upper pool – impoundment
• Lower pool – natural lake, river
or storage reservoir
• Advantages :
– Production of peak power
– Can be built anywhere with
reliable supply of water
The Raccoon Mountain project

43. Sizes of Hydropower PlantsSizes of Hydropower Plants
• Definitions may vary.
• Large plants : capacity >30 MW
• Small Plants : capacity b/w 100 kW to 30 MW
• Micro Plants : capacity up to 100 kW

44. Large Scale Hydropower plantLarge Scale Hydropower plant

45. Small Scale Hydropower PlantSmall Scale Hydropower Plant

46. Micro Hydropower PlantMicro Hydropower Plant

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

48. Generating TechnologiesGenerating Technologies
• Types of Hydro Turbines:
– Impulse turbines
• Pelton Wheel
• Cross Flow Turbines
– Reaction turbines
• Propeller Turbines : Bulb turbine, Straflo, Tube
Turbine,
Kaplan Turbine
• Francis Turbines
• Kinetic Turbines

49. Impulse TurbinesImpulse 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.
• No suction downside, water flows out through turbine housing
after hitting.
• High head, low flow applications.
• Types : Pelton wheel, Cross Flow

50. Pelton WheelsPelton Wheels
• Nozzles direct forceful
streams of water against a
series of spoon-shaped
buckets mounted around the
edge of a wheel.
• Each bucket reverses the
flow of water and this
impulse spins the turbine.

51. Pelton Wheels (continued…)Pelton Wheels (continued…)
• Suited for high head, low
flow sites.
• The largest units can be up
to 200 MW.
• Can operate with heads as
small as 15 meters and as
high as 1,800 meters.

52. Cross Flow TurbinesCross Flow Turbines
• drum-shaped
• elongated, rectangular-
section nozzle directed
against curved vanes on a
cylindrically shaped runner
• “squirrel cage” blower
• water flows through the
blades twice

53. Cross Flow Turbines (continued…)Cross Flow Turbines (continued…)
• First pass : water flows from the outside of the
blades to the inside
• Second pass : from the inside back out
• Larger water flows and lower heads than the
Pelton.

54. Reaction TurbinesReaction 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.

55. Propeller Hydropower TurbinePropeller Hydropower Turbine
• Runner with three to six blades.
• Water contacts all of the blades
constantly.
• Through the pipe, the pressure is
constant
• Pitch of the blades - fixed or
adjustable
• Scroll case, wicket gates, and a
draft tube
• Types: Bulb turbine, Straflo, Tube
turbine, Kaplan

56. Bulb TurbineBulb Turbine
• The turbine and
generator are a sealed
unit placed directly in the
water stream.

57. Others…Others…
• Straflo : The generator is attached directly to the perimeter of
the turbine.
• Tube Turbine : The penstock bends just before or after the
runner, allowing a straight line connection to the generator
• Kaplan : Both the blades and the wicket gates are adjustable,
allowing for a wider range of operation

58. Kaplan TurbineKaplan Turbine
• The inlet is a scroll-shaped tube
that wraps around the turbine's
wicket gate.
• Water is directed tangentially,
through the wicket gate, and
spirals on to a propeller shaped
runner, causing it to spin.
• The outlet is a specially shaped
draft tube that helps decelerate the
water and recover kinetic energy.

59. Francis TurbinesFrancis Turbines
• The inlet is spiral shaped.
• Guide vanes direct the water
tangentially to the runner.
• This radial flow acts on the runner
vanes, causing the runner to spin.
• The guide vanes (or wicket gate)
may be adjustable to allow
efficient turbine operation for a
range of water flow conditions.

60. Francis Turbines (continued…)Francis Turbines (continued…)
• Best suited for sites with
high flows and low to
medium head.
• Efficiency of 90%.
• expensive to design,
manufacture and install,
but operate for decades.

61. Kinetic Energy TurbinesKinetic Energy Turbines
• Also called free-flow turbines.
• Kinetic energy of flowing water used rather than potential
from the head.
• Operate in rivers, man-made channels, tidal waters, or ocean
currents.
• Do not require the diversion of water.
• Kinetic systems do not require large civil works.
• Can use existing structures such as bridges, tailraces and
channels.

62. Hydroelectric Power Plants in IndiaHydroelectric Power Plants in India
Baspa II Binwa

63. Continued …Continued …
Gaj Nathpa Jakri

64. Continued…Continued…
Rangit Sardar Sarovar

65. ENVIRONMENTAL IMPACTENVIRONMENTAL IMPACT

66. Benefits…Benefits…
• Environmental Benefits of Hydro
• No operational greenhouse gas emissions
• Savings (kg of CO2 per MWh of electricity):
– Coal 1000 kg
– Oil 800 kg
– Gas 400 kg
• No SO2 or NOX
• Non-environmental benefits
– flood control, irrigation, transportation, fisheries and
– tourism.

67. DisadvantagesDisadvantages
• The loss of land under the reservoir.
• Interference with the transport of sediment by the dam.
• Problems associated with the reservoir.
– Climatic and seismic effects.
– Impact on aquatic ecosystems, flora and fauna.

68. Loss of landLoss of land
• A large area is taken up in the form of a reservoir in case of
large dams.
• This leads to inundation of fertile alluvial rich soil in the
flood plains, forests and even mineral deposits and the
potential drowning of archeological sites.
• Power per area ratio is evaluated to quantify this impact.
Usually ratios lesser than 5 KW per hectare implies that the
plant needs more land area than competing renewable
resources. However this is only an empirical relation.

69. Methods to alleviate the negativeMethods to alleviate the negative
impactimpact
• Creation of ecological reserves.
• Limiting dam construction to allow substantial free flowing
water.
• Building sluice gates and passes that help prevent fishes
getting trapped.

70. Favorable impactFavorable impact
• Enhanced fishing upstream.
• Opportunities for irrigated farming downstream.
• With the flooding of the forest habitat of the Tsetse fly, the
vector of this disease, the problem of Sleeping Sickness has
been substantially reduced.

71. Technological advancementsTechnological advancements
• Technology to mitigate the negative environmental impact.
– Construction of fish ways for the passage of fish
through, over, or around the project works of a
hydro power project, such as fish ladders, fish
locks, fish lifts and elevators, and similar physical
contrivances
– Building of screens, barriers, and similar devices
that operate to guide fish to a fish way

72. Continued…Continued…
• Evaluating a new generation of large turbines
– Capable of balancing environmental, technical,
operational, and cost considerations
• Developing and demonstrating new tools
– to generate more electricity with less water and
greater environmental benefits
– tools to improve how available water is used
within hydropower units, plants, and river systems
• Studying the benefits, costs, and overall effectiveness of
environmental mitigation practices