1. POOJA S NATHAN
S1 BT(2014 BATCH)
SCET KODAKARA

2. Energy
HydroHydro powerpower
Nucl ea
r
f uel s
Re ne wable
e ne rg y
Ocean
energy
No n Re ne wable
Ene rg y
Sol ar
energy
Wi nd
energy
Fos s i l
f uel s

3. WHAT IS RENEWABLE
ENERGY?
Renewable energy is energy generated from
natural resources—such as sunlight, wind,
rain, tides and geothermal heat—which
are renewable (naturally replenished).
Renewable energy technologies range
from solar power, wind power,
hydroelectricity/micro hydro, biomass and
biofuels for transportation.

4. Introduction
• Hydroelectric power (hydropower) systems
convert thekinetic energy in flowing water
into electric energy.
• Falling or flowing water turnsapropeller like
piececalled aturbine.
• Theturbineturnsametal shaft in an electric
generator which produceselectricity.

6. Selection of site
• The site for Hydraulic power plant is selected
considering the following factors
 Water available.
 Storage of water.
 Head of water.
 Distance from load center.
 Accessibility of the site.
 The land of site should be cheap and rocky.

9. Components of hydel scheme
Theprincipal componentsare:
1.Forebay
2.Intakestructure
3.Penstocks
4.Surgetank
5.Turbines
6.Power house
7.Draft tube
8.Tail race

10. Dams
• A Dam is a structure of masonry built at a
suitable location across a river.
• The primary function of the dam is to provider the
head of water.
• Dams are classified based on
 Function
 Shape
 Construction materials
 Design

11. • Dams - Classification
DAM
Functions
Shape
Construction
material
Design
Storage Dams
Diversion Dams
Arch Dam
Trapezoidal
Stone masonry
RCC
Structural
Hydraulic
Overflow
Non-overflow
Buttress
Earth
Rock fill
Arch
Gravity

12. Forebay
• Forebay acts as a regulating reservoir
temporarily
• The forebay has the following parts
 Entrance bay
 Spillway
 Flushing sluice
 Screens
 Valve chamber
 Penstock inlet

13. Forebay
• Enlarged body of water provided in front of
penstock.
• Provided in caseof run off river plantsand
storageplants.
• Main function to storewater which isrejected
by plant.
• Power houselocated closed to dam penstock
directly takewater from reservoir, reservoir
act asforebay.

15. Intake structure
• Water conveyed from forebay to penstocks
through intakestructures.
• Main componentsaretrash rack and gate.
• Trash rack prevent entry of debris.

16. Trash rack
• It is provided for preventing the debris from
getting into the intakes from dam or from the
forebay
• Trash rack is made up of steel bars
• The spacing of bars depends upon the following
factors
 Type of turbine
 Size of floating material
 Velocity of flow through trash rack.

17. Waterway
• A waterway is used to carry water from the dam to
powerhouse.
• It includes canal, penstock and tunnel
• Tunnel is the passage by cutting mountain to reduce
the length of waterway to reservoir and the power
house.
• The tunnel is either circular or horse shoe shaped.
• A canal is an open structure constructed on earth or
rock.
• The canal should be located on the economically short
route. ……….

18. • Penstock is a pipe which carry the water from
reservoir to turbine house.
• Penstock is made up of steel or reinforced concrete
or wood.
• Penstock should be sloping towards the powerhouse.
• Sharp bends should be avoided and require special
anchorages .
• The intake of the penstock should be at a low level to
provide adequate water seal under all conditions

19. Surge tank
• additional storage for near to turbine, usually
provided in high head plants.
• located near the beginning of the penstock.
• Astheload on theturbinedecreasesor during
load rejection by theturbinethesurgetank
providesspacefor holding water.

20. • surgetank over comestheabnormal pressure
in theconduit when load on theturbinefallsand
actsasareservoir during increase of load
on theturbine.

21. Turbines
• turbinesareused to convert theenergy water
of falling water into mechanical energy.
• water turbineisarotary engine that takes
energy from moving water.
• flowing water isdirected on to thebladesof a
turbinerunner, creating aforceon theblades.

22. • Sincetherunner isspinning, theforceacts
through adistancen thisway, energy is
transferred from thewater flow to theturbine.
• Theprincipal typesof turbinesare:
1) Impulseturbine
2) Reaction Turbine

23. Draft tube
• A Draft tube connects the
runner exit to tail race.
• Draft tube provides a
negative head at the
runner outlet by which it is
possible to attach a turbine
above the tail race.
• The outlet velocity of
water is reduced and a
gain in pressure head i.e.
the net working head of
turbine is increased.

25. Power house
• Power housecontainstheelectro mechanical
equipment i.e. hydro power turbine, Generator,
excitation system, main inlet valves,
transformers, Switchyard, DC systems,
governor, busduct, step up transformers, step
down transformers, high voltagesswitch gears,
control metering for protection of systems.

26. Tail race
• tail racetunnel or channel areprovided to
direct theused water coming out of draft tube
back to theriver.
• important criteriaof designing thetail raceis
kind of draft tube, thegrosshead and
geographical situation of thearea.
• Tail raceisdesigned in such away that water
hammer isminimizeswhen water leavesthe
draft tube.

27. Theamount of electricity that can begenerated by a
hydropower plant dependson two factors:
• flow rate - thequantity of water flowing in agiven
time; and
• head - theheight from which thewater falls.
Thegreater theflow and head, themoreelectricity
produced.
Flow Rate= thequantity of water flowing
Head = theheight from which water falls
Power generation

28. Power= theelectric power in kilowattsor kW
Head = thedistancethewater falls(measured in feet)
Flow = theamount of water flowing (measured in cubic feet per
second or cfs)
Efficiency = How well theturbineand generator convert thepower
of falling water into electric power. Thiscan rangefrom 60%
(0.60) for older, poorly maintained hydroplantsto 90% (0.90) for
newer, well maintained plants.
11.8 = Index that convertsunitsof feet and secondsinto kilowatts
A standard equation for calculating energy production:
Power = (Head) x (Flow) x (Efficiency)
11.8

29. Hydroelectric power (often called hydropower)is
considered a renewable energy source. A
renewable energy source is one that is not depleted
(used up) in the production of energy. Through
hydropower, the energy in falling water is converted
into electricity without “using up” the water.

30. Hydropower energy is ultimately derived from the
sun, which drives the water cycle. In the water
cycle, rivers are recharged in a continuous cycle.
Because of the force of gravity, water flows from
high points to low points. There is kinetic energy
embodied in the flow of water.

31. Kinetic energy is the energy of motion. Any moving
object has kinetic energy.

32. Humans first learned to
harness the kinetic energy in
water by using
waterwheels.
A waterwheel is a revolving
wheel fitted with blades,
buckets, or vanes.
Waterwheels convert the
kinetic energy of flowing
water to mechanical
energy.

33. Mechanical energy is a form of kinetic energy, such as in a
machine. Mechanical energy has the ability to do work. Any
object that is able to do work has mechanical energy.

34. Hydroelectric power (hydropower) systems convert the
kinetic energy in flowing water into electric energy.

35. 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.
How a Hydroelectric Power System Works - Part 1

36. 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 – Part 2

37. 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.
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.

38. Disadvantages
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.
5. The building of large dams can cause serious geological
damage. For example, the building of the Hoover Dam in
the USA triggered a number of earth quakes and has
depressed the earth’s surface at its location.

39. SIGNIFICANCE
Hydropower stands as the most significant
renewable energy source. It uses the single but
very powerful energy force of moving water. By
some comparison, it competes with the energy
produced by fossil fuels and nuclear power, but
is considered much cleaner and more simplistic.
Hydropower remains popular even in third-world
countries, which do not have the resources to
build expensive nuclear generating stations.
Hydropower does not pollute the atmosphere or
environment.

40. Facts
• Hydropower uses the energy of moving water for a
variety of useful applications.
• Hydroelectricity generates electricity by harnessing the
gravitational force of falling water.
• In 2006, hydroelectricity supplied around 20% of the
world’s electricity.
• Most hydroelectric power stations use water held in
dams to drive turbines and generators which turn
mechanical energy into electrical energy.
• The largest hydroelectric power station in the world is the
Three Gorges Dam in China.

41. Environmental Impacts
• Hydroelectric power includes both massive
hydroelectric dams and small run-of-the-river
plants. Large-scale hydroelectric dams continue
to be built in many parts of the world (including
China and Brazil), but it is unlikely that new
facilities will be added to the existing U.S. fleet in
the future.
• Instead, the future of hydroelectric power in the
United States will likely involve increased
capacity at current dams and new run-of-the-
river projects. There are environmental impacts
at both types of plants.

42. • The IHA (International Hydropower Association)
Working Group on Environmental Impact
Assessment (EIA) calls for impact assessment
to be an integral part of the multidisciplinary
planning approach, and to include a strong
element of public consultation. EIAs should
cover both positive and negative impacts both
upstream and downstream of a proposed
project.

43. Economic Impacts
Large dams have long been promoted as providing
"cheap" hydropower and water supply. Today,
we know better. The costs and poor
performance of large dams were in the past
largely concealed by the public agencies that
built and operated the projects. Dams
consistently cost more and take longer to build
than projected. In general, the larger a hydro
project is, the larger its construction cost overrun
in percentage terms.

44. SOCIAL ISSUES
• Relocating people from the reservoir area is the
most challenging social aspect of hydropower,
leading to significant concerns regarding local
culture, religious beliefs, and effects associated
with inundating burial sites. While there can
never be a 100 percent satisfactory solution to
involuntary resettlement, enormous progress
has been made in the way the problem is
handled.