Hydroelectric power plants convert the potential energy of flowing water into electricity, with their output dependent on the flow and head of water. They play a crucial role in energy generation, particularly in India, where they contribute to over a quarter of the total electricity generation capacity. Various types of turbines and classification methods exist, with benefits including low operational costs and environmental advantages, though high initial capital costs and dependency on water availability are notable disadvantages.

1. HYDRO ELECTRIC POWER PLANT

2. WHAT IS HYDRO POWER?
The objective of a hydropower scheme is to convert the
potential energy of water, flowing in a stream with a
certain fall to the turbine (termed the "head"), into electric
energy at the lower end of the scheme, where the powerhouse
is located. The power output from the scheme is proportional
to the flow and to the head.

3. HYDRO-POWER PLANT
• It plays very important role in the development
of country.
• It provides power at cheapest rate.
• About 20% of the total world power is
generated using hydro power plants.

4.  4% of the total hydel energy potential in world
is in India.
 In India 25.32% of total electricity generation
capacity is produced by hydel power plant.
 As per records of March-2000 23,816 MW
electricity was generated by hydel power plant.
 It is increasing day by day because of the
institutes like National Hydro Power
Corporation Limited(NHPCL).
HYDRO-POWER PLANTHYDRO-POWER PLANT

5. DAM TURBINE
POWER HOUSE
INTAKE
GENERATOR
PENSTOCK
RESEVOIR
POWER LINE
TRANSFORMER

7. HOW A HYDROELECTRIC POWER SYSTEM WORKS
Flowing water is directed at a
turbine (remember turbines
are just advanced
waterwheels).
The flowing water causes the
turbine to rotate, converting
the water’s kinetic energy
into mechanical energy.
A control mechanism to
provide stable electrical
power. It is called governor.

8. The mechanical energy produced by the turbine is converted into
electric energy using a turbine generator. Inside the generator, the shaft
of the turbine spins a magnet inside coils of copper wire. It is a fact of
nature that moving a magnet near a conductor causes an electric
current.
HOW A HYDROELECTRIC POWER SYSTEM WORKS

9. 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.

10. Classification of Hydro electric power station.
• CLASSIFICATION BASED ON HEAD.
A. High head plant ( < 300 m.)
B. Medium head plant. (60m to 300 m.)
C. Low head plant. ( > 60m.)
• CLASSIFICATION BASED ON WATER CONDITION.
A. Flow of water plant.
B. Storage of water plant.
C. Pump storage water plant.

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

12. HYDRO POWER PLANT
• Head
– Water must fall from a higher elevation to a lower one to
release its stored energy.
– The difference between these elevations (the water levels in
the forebay and the tailbay) is called head.
• Dams: Are of three categories.
– high-head (800 or more feet)
– medium-head (100 to 800 feet)
– low-head (less than 100 feet)
• Power is proportional to the product of
head x flow
12

13. Element of Hydro power station,
1. Reservoir.
2. Catchments area.
3. Dam.
• (a) Earthen dam.
• (b) Masonry dam.
• (c) Concrete dam.
• 4. Spill ways.
• 5. Screen.
• 6. Fore bay or Intake.

14. Element of Hydro power station,
• 7. Tunnel.
• 8. Penstock or pipe line.
• 9. Surge tank.
• 10. Draft tube.
• 11. Tail race.
• 12. Fish passes.
• 13. Turbine.

15. Different type of turbine use in hydro
power station
• 1.High head schemes. (Impulse turbine, pelton wheel)
• 2.Medium head schemes. (reaction turbine )
• 3.Low head schemes. (propeller turbine )

16. Micro Hydro Example
Used in remote locations in northern Canada

17. Pumped Storage Schematic

18. Cabin Creek Pumped Hydro
18
• base load capacity
– Water flows downhill during day/peak periods
• Typical efficiency of 70 – 85%Completed 1967
• Capacity – 324 MW
– Two 162 MW units.
• Purpose – energy storage
– Water pumped uphill at night
• Low usage – excess

19. ADVANTAGES OF PUMPED STORAGE PLANT
• There is substantial increase in peak load
capacity of plant at comparatively low capital
cost.
• There is an improvement in the load factor of
plant.
• Load on hydro-electrical plant remains
uniform.

20. FIRST ELEMENT :-
DAMS
DAM TYPES
1. Arch
2. Gravity
3. Buttress
4. Embankment or
Earth

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

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

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

24. Turbine Ranges of Application
24
Boyle, Renewable Energy, 2nd
edition, Oxford University Press, 2003

25. Turbine Design Recommendations
Head Pressure
High Medium Low
Impulse Pelton
Turgo
Multi-jet Pelton
Crossflow
Turgo
Multi-jet Pelton
Crossflow
Reaction Francis
Pump-as-Turbine
Propeller
Kaplan

26. Turbine Classified

27. Turbine Design Ranges
• Kaplan
• Francis
• Pelton
• Turgo
2 < H < 40
10 < H < 350
50 < H < 1300
50 < H < 250
(where H = head in
meters)

28. LIST OF VARIOUS FACTORS WHICH DESCRIBE THE
SELECTION OF TURBINE
• Specific speed; high specific speed is essential where head is
low.
• Rotational speed;
• Efficiency;
• Part of load operation;
• Cavitations;
• Disposition of turbine shaft;
• Head;

29. Types of Hydropower Turbines

30. • REACTION TURBINES
– Derive power from pressure drop across turbine.
– Totally immersed in water.
– Angular & linear motion converted to shaft power.
– Propeller, Francis, and Kaplan turbines
• IMPULSE TURBINES
– Convert kinetic energy of water jet hitting buckets.
– No pressure drop across turbines.
– Pelton, Turgo, and crossflow turbines

31. 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.
• No suction downside, water flows out through turbine
housing after hitting.
• High head, low flow applications.
• Types : Pelton wheel, Cross Flow

32. 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.

33. Chain Turbine

34. Advantages of Chain Turbine
• It is run-of-river power plant.
• Do not worry about the turbidity of water.
• There is no danger of cavitations.
• It is simple to construct, repaired and
maintenance.

35. Disadvantages of Chain Turbine
• The slow rotation of chain turbine leads to
high speed ratios when connect to
generator at 600 rpm – 1500 rpm.
• This chain turbine operation is very noisy.
• Structure of turbine is very big.

36. Pelton Wheel Turbine

37. Pelton 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.

38. Pelton Wheels
• 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.

39. Francis Turbine Cross-Section

40. Kaplan Turbine Schematic

41. View of penstock &draft tube in Hydro
power plant.

42. “used for conveying water from the intake to the power
house”.
The water in the reservoir is considered as stored energy.
When the gate opens, the water flowing through the
penstock strikes the turbine.
PENSTOCK

43. Function of surge tank
• Its function is to prevent sudden increase of pressure in the
supply line or in the penstock. It is placed as near as possible
to the turbine.
• Water hammer
• Due to the variation in the demand of water supply according
to load, the turbine gates get closed suddenly which cause
increase in pressure. This is known as water hammer.

44. TRASH RACK
Almost all small hydroelectric plants have a trash rack
cleaning machine, which removes all material from water
in order to avoid entering in plants intake water.

45. After passing through the turbine the water returns to
the river trough a short canal called a tailrace.
Tailraces:-Tailraces:-

46. Function of spillway is to discharge the excess amount of water
during floods and keep the level of water to the head of reservoir.
During the lifetime of a dam different flow conditions will be
experienced and a dam must be able to safely accommodate high
floods that can exceed normal flow conditions in the river. For this
reason, carefully passages are corporated in the dams as a part of
structure. These passages are known as spillways.
What is the function of Spill ways?What is the function of Spill ways?

47. Advantage of Hydro power station.
1. The plant is simple in construction ,robust and required
low maintenance.
2. It can be put in the service instantly.
3. It can respond to changing loads without any difficulty.
4. There are no stand by losses.
5. The running charges are very small.
6. No fuels is burnt.
7. The plant is quite neat and clean.
8. The water after running the turbine can be used for
irrigation and other purpose.

48. Disadvantage of Hydro power station.
1. The capital cost of generators, civil engineering work etc is
high.
2. High cost of transmission lines.
3. Long dry seasons may effect the delivery of power.

49. Selection of site for Hydro electric power
station.
1. sufficient quantity of water at a reasonable head should be
available.
2. The site should allow for strong foundations with minimum
cost.
3. There should be no possibility of future source of leakage of
water.
4. The selected site should be accessible easily.
5. There should be possibility of stream diversion during
construction period.
6. The reservoir to be constructed should have large catchments
area, so that the water in it should never fall below the
minimum level.

50. Benefits…
• Environmental Benefits of Hydro power plant.
• No operational greenhouse gas emissions.
Non-environmental benefits
– flood control, irrigation, transportation, fisheries
and tourism.

51. Hydropower Calculations
HQP
HQgP
×××≅
×××=
η
η
10
• P = power in kilowatts (kW)
• g = gravitational acceleration (9.81 m/s2
)
• η = turbo-generator efficiency (0<n<1)
• Q = quantity of water flowing (m3
/sec)
• H = effective head (m)