This document discusses various renewable energy sources including solar energy, wind energy, bio energy, geothermal energy, water energy, and tidal energy. It provides details on how each type of energy is harnessed, examples of applications, and advantages and disadvantages. For solar energy, it describes how solar energy can be used for water heating, cooking, generating electricity via solar cells and panels, and water treatment. For wind energy, it discusses wind turbines and their use in India. Bio energy covers biomass and biogas production. Geothermal energy explains how heat from the earth can be tapped. Water energy captures the kinetic energy of moving water.

1. HARVESTING ENERGY
Sahil Khanna Samridhi Nanda
Prabhdeep Singh Pooja Khanna
Shaminder Saini Shareen Aulakh
8L

2. Contents
• Introduction
• Energy Forms
• Solar Energy
• Wind Energy
• Bio Energy
• Geothermal Energy
• Water Energy
• Tidal Energy

3. Introduction
The Real Scenario

4. Consequences
Yes, It Can Happen

5. What If?
• We have been meeting up our daily needs with the help of
various non-renewable sources like
coal, petroleum, nuclear energy and many more but have
you ever imagined what will happen if they all go extinct.
 Will it be able to satisfy our next generations with
minimum resources?
 Will we have enough electricity or petrol to run our
houses/industries and cars?
 Will it be possible to survive in such surroundings which
will be full of poisonous gases and smoke?
 Will basic necessities like potable water and shelter would
be available in abundance?

6. But Yes, There is a Solution
• Energy from SUN, WATER,
WIND, BIOMASS,
GEOLOGY and TIDES can
help us to tackle the
increasing energy
problems in the world.
Because they are:
 Free
 Non Polluting
 Never Ending
 Lifetime Services in return
of a small investment.

7. Solar Energy
• Solar energy,
radiant light and heat
from the sun, has
been harnessed by
humans since ancient
times.
• Solar energy is widely
available, free and
pollution free.

8. How much Solar Energy?
The surface receives about 47% of the total solar
energy that reaches the Earth. Only this amount is
usable.

9. Putting Solar Energy to Use
Solar Energy can be utilized in various ways which
includes:
 Water Heating
 Cooking
 Solar Cells & Panels
 Water Treatment

10. Water Heating using Solar Energy
• Two methods of heating
water: passive (no moving
parts) and active (pumps).
• In both, a flat-plate collector
is used to absorb the sun’s
energy to heat the water.
• The water circulates
throughout the closed system
due to convection currents.
• Tanks of hot water are used
as storage.

11. Heating Water: Active System
Active System uses antifreeze so that the liquid does
not freeze if outside temp. drops below freezing.

12. Cooking with Solar Energy
• Solar cookers use
sunlight for cooking and
drying .
• Three types: Box
cookers, panel cookers
and reflector cookers.
• Solar cookers use no
fuel, which means that
their users do not need
to fetch or pay for
firewood, gas, electricity,
or other fuels.

13. Solar Cells & Solar Panels
• A solar cell (also called photovoltaic cell or photoelectric cell) is a solid
state electrical device that converts the energy of light directly
into electricity by the photovoltaic effect.
• A solar panel is a packaged interconnected assembly of solar cells, also
known as photovoltaic cells.
• The solar panel can be used as a component of a larger photovoltaic
system to generate and supply electricity in commercial and residential
applications.
• They are widely used in Calculators, watches, Traffic lights and
spacecrafts(SKYLAB Space Laboratory and International Space Station).

14. Water Treatment
• Solar distillation can be used to
make saline or brackish water potable.
• Solar water disinfection (SODIS) involves
exposing water-filled plastic polyethylene
terephthalate (PET) bottles to sunlight for
several hours.
• Exposure times vary depending on weather
and climate from a minimum of six hours to
two days during fully overcast conditions.
• Solar energy may be used in a water
stabilisation pond to treat waste
water without chemicals or electricity.

15. Advantages & Disadvantages
Advantages:
• Non polluting: no noise, no harmful or unpleasant emissions or smells.
• Very reliable: most solar panels have a 25 year warranty and even a
longer life expectancy (the theory is they could last 100 to 125 years).
• Solar modules over their lifetime produce more power per gram of
material than nuclear power but without the problem of large volumes
of environmentally hazardous material.
• Solar Power is a renewable energy source. It is a resource that cannot
be used up by us using it.
Disadvantages:
• Sun does not shine consistently.
• Solar energy is a diffuse source. To harness it, we must concentrate it
into an amount and form that we can use, such as heat and electricity.
• Addressed by approaching the problem through:
1) collection, 2) conversion, 3) storage.

16. WIND ENERGY
• All renewable energy (except tidal and geothermal power), ultimately
comes from the sun
• The earth receives 1.74 x 1017 watts of power (per hour) from the sun
• About one or 2 percent of this energy is converted to wind energy(which is
about 50-100 times more than the energy converted to biomass by all
plants on earth
• Differential heating of the earth’s surface and atmosphere induces vertical
and horizontal air currents that are affected by the earth’s rotation and
contours of the land to WIND.~ e.g.: Land Sea Breeze Cycle

17. Why we need wind energy?
Cost Competitiveness
Environmental
Awareness/
Government Initiatives
Energy Security
Increased Electricity
Demand
• Cost per Kwh of wind generation decreased from US$ 0.38 in
early 80s to present US$ 0.03-0.06, at excellent wind sites (1)
• Rising Oil &Gas prices makes Wind Energy cost competitive
• Kyoto Protocol Implementation - Carbon-dioxide emission to
reduce by 5.2% of 1990s levels, by 2012
• Implementation of Renewable Portfolio Standard requires
minimum percentage of power generation from Renewable
Energy
• Price volatility of Oil &Gas have increased focus on Renewable
Energy
• Global Electricity Consumption expected to double between
2002 & 2030(2)
– higher growth in India and China
• Wind Energy’s contribution expected to increase from 0.2% in
2002 to 3% in 2030 (3)

18. Windmill
• A windmill is a machine which
converts the energy of wind into
rotational energy by means of
vanes called sails or blades .
• A Windmill captures wind energy
and then uses a generator to
convert it to electrical energy.
• When designing a windmill, one
must decide on the size of the
turbine, and the size of the
generator

19. Wind Turbines
 LARGE TURBINES:
• Able to deliver electricity at lower cost than smaller turbines, because
foundation costs, planning costs, etc. are independent of size.
• In areas where it is difficult to find sites, one large turbine on a tall tower
uses the wind extremely efficiently.
• Well-suited for offshore wind plants.
 SMALL TURBINES:
• Local electrical grids may not be able to handle the large electrical output
from a large turbine, so smaller turbines may be more suitable.
• High costs for foundations for large turbines may not be economical in
some areas.
• Landscape considerations

20. A Large Wind Turbine Small Wind Turbines scattered over a field

21. India Wind Energy Use
 The installed capacity of wind power in India is 13065.37 MW.
 Wind power accounts for 6% of India's total installed power
capacity, and it generates 1.6% of the country's power.
 Mainly spread across Tamil Nadu (4906.74 MW), Maharashtra
(2077.70 MW), Gujarat (1863.64 MW), Karnataka (1472.75
MW), Rajasthan (1088.37 MW), Madhya Pradesh (229.39
MW), Andhra Pradesh (136.05 MW), Kerala (27.75
MW), Orissa (2MW), West Bengal (1.1 MW) and other states
(3.20 MW).
 India is 5th largest wind energy producer in the world.

22. Advantages
• The wind blows day and night, which allows windmills to
produce electricity throughout the day. (Faster during the day)
• Energy output from a wind turbine will vary as the wind
varies, although the most rapid variations will to some extent
be compensated for by the inertia of the wind turbine rotor.
• Wind energy is a domestic, renewable source of energy that
generates no pollution and has little environmental impact.
Up to 95 percent of land used for wind farms can also be used
for other profitable activities including ranching, farming and
forestry.

23. Disadvantages
 Main disadvantage regarding wind power is down to the winds
unreliability factor. In many areas, the winds strength is too low to
support a wind turbine or wind farm.
 Wind turbines generally produce allot less electricity than the
average fossil fuelled power station, requiring multiple wind
turbines to be built in order to make an impact.
 Wind turbine construction can be very expensive and costly to
surrounding wildlife during the build process.
 The noise pollution from commercial wind turbines is sometimes
similar to a small jet engine. This is fine if you live miles away,
where you will hardly notice the noise, but what if you live within a
few hundred meters of a turbine? This is a major disadvantage.

24. Bio Energy
• Bioenergy is renewable energy
made available from materials
derived from biological
sources.
• It basically includes Biomass
which is any organic material
which has stored sunlight in
the form of chemical energy.
As a fuel it may include wood,
wood waste, straw, manure,
sugarcane, and many other
byproducts from a variety of
agricultural processes.

25. Solid Biomass
 Biomass is material derived
from recently living
organisms, which includes
plants, animals and their by
products. Manure, garden
waste and crop residues are all
sources of biomass. It is a
renewable energy source
based on the carbon
cycle, unlike other natural
resources such as
petroleum, coal, and nuclear
fuels.

26. Bio Gas
 A mixture of methane and carbon dioxide.
CH4
CO2
Methane or ‘swamp gas’, produced
naturally in swampy ponds

27. How is Biogas Made?

28. Bio-Energy Uses
Biogas is a fuel used as an energy source
for light, heat or movement

29. Advantages and Disadvantages
ADVANTAGES
 help to manage the marsh gas
pollution
 improve the air quality
 recycle rubbish
 no greenhouse emission
 reduction of air pollution and acid
rain
DISADVANTAGES
 storage problem (for recycled
material)
 cost for transporting and
transferring

30. Geothermal Energy
• Geothermal energy- energy that
comes
from the ground; power extracted
from
heat stored in the earth
From hot springs, geothermal energy
has been used for bathing since
Paleolithic times and for space
heating since ancient Roman times,
but it is now better known for
electricity generation.
Worldwide, about 10,715 megawatts
(MW) of geothermal power is Online
in 24 countries.

31. Why we use geothermal energy?
• It is renewable
• It doesn’t cause pollution
• Owners of buildings using geothermal have cut 25 to 50
percent off their utility bills.
• No cooling towers, rooftop units, or individual room air
conditioning units are needed, so buildings and schools using
geothermal systems look better.
• There is no fire hazard and no outside equipment that could
potentially hurt kids.

32. Categories of Geothermal
Resources
• Hot Water Reservoirs: geothermally heated
underground water.
• Natural Steam Reservoirs: Instant steam but
they are very rare
• Geopressurized Reservoirs
• Normal Geothermal Gradient
• Hot Dry Rock
• Molten Magma

33. How geo thermal works?

34. Conventional Uses of
Geothermal Energy
• A Tourist Attraction - come
sit in our hot springs with
people you don't know
• As a direct source of space
heating
• As an instant steam
generating facility to spin a
turbine
• There are production sites in
New Zealand, Iceland and, of
course, California

35. Geothermal energy in India
 India has reasonably good potential for geothermal; the potential
geothermal provinces can produce 10,600 MW of power.
 But yet geothermal power projects has not been exploited at all, owing to
a variety of reasons, the chief being the availability of plentiful coal at
cheap costs.
 Potential Sites:
• Puga Valley (J&K)
• Tatapani (Chhattisgarh)
• Godavari Basin Manikaran (Himachal Pradesh)
• Bakreshwar (West Bengal)
• Tuwa (Gujarat)
• Unai (Maharashtra)
• Jalgaon (Maharashtra)

36. Advantages
• When a power station harnesses geothermal power in the
correct manner, there are no by products, which are
harmful to the environment. Environmentalists should be
happy about that!
• There is also no consumption of any type of fossil fuels. In
addition, geothermal energy does not output any type of
greenhouse effect. After the construction of a geothermal
power plant, there is little maintenance to contend with. In
terms of energy consumption, a geothermal power plant is
self-sufficient.
• Another advantage to geothermal energy is that the power
plants do not have to be huge which is great for protecting
the natural environment.

37. Disadvantages
• There are several disadvantages to geothermal energy.
First, you cannot just build a geothermal power plant in
some vacant land plot somewhere. The area where a
geothermal energy power plant would be built should
consist of those suitable hot rocks at just the right depth for
drilling. In addition, the type of rock must be easy to drill
into. It is important to take care of a geothermal site
because if the holes were drilled improperly, then
potentially harmful minerals and gas could escape from
under ground. These hazardous materials are nearly
impossible to get rid of properly.
• Pollution may occur due to improper drilling at geothermal
stations. Unbelievably, it is also possible for a specific
geothermal area to run dry or lose steam.

38. Water Energy
• Water energy is a renewable energy
source because it relies on the
supply of water, a product on our
planet that we have infinite supply
of. When water flows or falls, it
creates water energy, and this
energy source is quickly becoming
the most widely used form of
renewable energy. While most dams
are created to prevent flooding and
to provide irrigation, there are some
dams that are mainly used for water
energy purposes.

39. How It Can Be Done?
Capturing runoff from
rooftops
Capturing runoff from local
catchments
Capturing seasonal
floodwaters from local
streams
Conserving water through
watershed management

40. How Can Water Harvesting Help?
• Provide drinking water
• Provide irrigation water
• Increase groundwater recharge
• Reduce storm water discharges, urban floods
and overloading of sewage treatment plants
• Reduce seawater ingress in coastal areas.

41. How water can be harvested?
Rural scenario
Our ancestors had learnt to harvest water in number of ways:
They harvested the rain drop directly. From rooftops, they
collected water and stored it in tanks built in their courtyards.
From open community lands, they collected the rain and stored
it in artificial wells.
They harvested monsoon runoff by capturing water from swollen
streams during the monsoon season and stored it various forms
of water bodies.
They harvested water from flooded rivers.

42. How water can be harvested?
Urban scenario
The total amount of water that is received in the form of rainfall
over an area is called the rainwater endowment of the area. Out
of this, the amount that can be effectively harvested is called the
water harvesting potential.
Water harvesting potential = Rainfall (mm) x Collection efficiency
The collection efficiency accounts for the fact that all the
rainwater falling over an area cannot be effectively
harvested, because of evaporation, spillage etc. Factors like
runoff coefficient and the first-flush wastage are taken into
account when estimated the collection efficiency.

43. Rainwater harvesting from rooftop
catchments
• Rooftop catchments: In the most basic form of this
technology, rainwater is collected in simple vessels at the
edge of the roof. As the rooftop is the main catchment area,
the amount and quality of rainwater collected depends on the
area and type of roofing material. Reasonably pure rainwater
can be collected from roofs constructed with galvanized
corrugated iron, aluminum or asbestos cement sheets, tiles
and slates, although thatched roofs tied with bamboo gutters
and laid in proper slopes can produce almost the same
amount of runoff. Roof catchments should also be cleaned
regularly to remove dust, leaves and bird droppings so as to
maintain the quality of the product water.

44. Rainwater Harvesting from rooftop catchments

45. Rainwater harvesting from
collection devices
Storage tanks: Storage tanks for
collecting rainwater harvested using
guttering may be either above or
below the ground. Precautions
required in the use of storage tanks
include provision of an adequate
enclosure to minimize contamination
from human, animal or other
environmental contaminants, and a
tight cover to prevent algal growth and
the breeding of mosquitoes. Open
containers are not recommended for
collecting water for drinking purposes.

46. Rainwater Harvesting from collection devices

47. Advantages
• Makes use of a natural resource and reduces
flooding, storm water runoff, erosion, and
contamination of surface water with pesticides,
sediment, metals, and fertilizers
• Excellent source of water for landscape irrigation,
with no chemicals such as fluoride and chlorine, and
no dissolved salts and minerals from the soil
• Home systems can be relatively simple to install and
operate May reduce your water bill Promotes both
water and energy conservation

48. Disadvantages
• Limited and uncertain local rainfall
• Can be costly to install.
• Requires some technical skills to install and provide
regular maintenance.
• Certain roof types may seep chemicals, pesticides,
and other pollutants into the water that can harm
the plants.
• Rainwater collected during the first rain season is
generally not needed by plants until the dry season.
Once catchment is full, cannot take advantage of
future rains.

49. Tidal Energy
• Tidal energy, is a form of
hydropower that
converts the energy of
tides into electricity or
other useful forms of
power.
• Tidal power has
potential for future
electricity generation as
tides are more
predictable than wind
energy and solar power.

50. Tides
• Tides generated by the combination
of the moon and sun’s gravitational
forces
• Greatest affect in spring when
moon and sun combine forces
• In order to be practical for energy
production, the height difference
needs to be at least 5 meters
• Only 40 sites around the world of
this magnitude
• Overall potential of 3000 gigawatts

51. How Tidal Energy Works?

52. Generating Method
• Tidal stream generator
Tidal stream generators (or TSGs) make use of the
kinetic energy of moving water to power
turbines, in a similar way to wind turbines that use
moving air.
• Dynamic tidal power
Dynamic tidal power (or DTP) is a theoretical
generation technology that would exploit an
interaction between potential and kinetic energies
in tidal flows. It proposes that very long dams be
built from coasts straight out into the sea or
ocean, without enclosing an area. Tidal phase
differences are introduced across the dam, leading
to a significant water-level differential in shallow
coastal seas – featuring strong coast-parallel
oscillating tidal currents such as found in the
UK, China and Korea.
The world's first commercial-scale and
grid-connected tidal stream generator –
SeaGen – in Strangford Lough.

53. • Tidal barrage
Tidal barrages make use of
the potential energy in the
difference in height (or
head) between high and
low tides. Barrages are
essentially dams across the
full width of a tidal estuary.

54. Advantages
• No pollution
• Renewable resource
• More efficient than wind because of the density of water
• Predictable source of energy vs. wind and solar
• Second generation has very few disadvantages
 Does not affect wildlife
 Does not affect silt deposits
 Less costly – both in building and maintenance
• Tidal energy does not depend on the weather.

55. Disadvantages
Presently costly:
Expensive to build and maintain.
A 1085MW facility could cost as much as 1.2 billion
dollars to construct and run
Technology is not fully developed
Barrage style has environmental affects
Such as fish and plant migration
Silt deposits
Local tides change- affects still under study

57. One day we will have to get up from our
slumber...and bear the consequences of our
present habits …. That would be the day we
will realize the importance of the non-
renewable resources.
So Let the day be today than tomorrow!
To avoid their depletion
Promote Use Of the renewable sources of
energy and harvest them in a better way
which can prove to be helpful not only to us
but also to the coming generations.