this presentation contain all kind of information about solar cell, geothermal energy and energy from the sea.

1. SOLAR CELL
GEOTHERMAL ENERGY
ENERGY FROM THE SEA

2. WHAT IS A SOLAR CELL ?
A solar cell is a device which
directly converts solar energy into
electrical energy.
In a solar cell, it is the light energy
present in solar energy which gets
converted into electrical energy.
So, a solar cell is also called a solar
photo voltaic (SPV) cell.
The radiant heat present in solar
energy doesn’t change into
electrical energy.
Solar cells are usually produced

4. PHOTO VOLTAIC EFFECT:
 This is a phenomenon due to
which light energy directly
changes into electrical energy
when light falls on certain light
sensitive materials like silicon ,
gallium, etc.

6. STRUCTURE OF A SOLAR CELL:-
A solar cell consist of a 4cm square
of a semiconductor silicon, in fact
it consist of a very thin sandwich
of n-type and p-type wafer of
silicon in which is placed a U-
shaped metal grid.

8. WORKING OF A SOLAR CELL:
When exposed to sunlight, the solar
radiations fall on a solar cell, the n-type
water produces a large number of
electrons.
These electrons drift towards p-type
wafer thereby generating an electric
potential.
A single cell of 4cm² silicon develops a
voltage of 0.5-1V and can produce about
0.7W of electricity when exposed to sun .
Presently, the best designed solar cell has
a maximum efficiency of about 25% i.e.
only 25% of the solar radiations falling on

9. SOLAR CELL PANEL:
A single cell can produce only a small
amount of electricity and low voltage.
To obtain a large potential difference
and more electric power, a large
number of solar cell are connected in
series and some in parallel. This
arrangement is called a solar cell
panel
The group of solar cells connected in
specific pattern to produce desired
potential difference or magnitude of
current (electric power) is called a

11. WORKING OF SOLAR CELL PANEL:
 Solar cells in the solar cell are connected by wires
made up of silicon so it increases the efficiency of
the solar panel.
 A solar panel is mounted on a tall supporting pole or
installed on a specially designed inclined roof tops so
that more solar energy is incident over it.
 The solar energy falling on the solar cells of the solar
cell panel gets converted into electricity .
 The electricity so produced flows to storage battery,
where the electricity is stored in the form of
chemical energy.
 This charged storage battery can supply electricity
whenever required.

13. ADVANTAGES OF SOLAR
CELLS/SOLAR CELL PANEL :
1. Solar cell have no moving parts, are easy to
construct, and require little maintenance.
2. Solar cell panel can be installed on remote
and very less populated areas in which
laying a power transmission line may be
expensive and not commercially viable.
3. Solar cell and solar cell panel are renewable
source of energy because both derive their
energy from solar radiations, which is a
renewable source of energy and also
inexhaustible.
4. Solar cells and solar cell panels do not cause
any environmental pollution.
5. Use of solar cells can enable us to save
usage of fossil fuels as solar cells require

14. DISADVANTAGES OF SOLAR CELL
PANELS:
1. Expensive manufacturing: the entire
process of manufacturing is
expensive because of use of
expensive components.
 (a) Special grade silicon required
for making solar cell is limited in
nature. So, it is very expensive.
 (b) Silver is used for
interconnecting various cells in a
solar cell panel is also expensive.
 (c) It is costly to store electricity
in a storage battery .

15. 2. Low efficiency: the efficiency of the
energy conversion is low as
compared to other methods of
generating electricity. The maximum
efficiency of solar cell is 25% which
is very low .It means it can convert
only about 25% of light energy
falling on them, into electricity.
3. Conversion problem: the electricity
produced in the solar panel is direct
current which is stored in DC
(direct current) batteries. Only DC
devices can be operated by DC
batteries. Now most of our electric
appliances operate on alternating
current (AC). To operate any AC
devices, we need to convert DC

16. USE OF SOLAR PANELS:
 In spit of the high cost, low efficiency and
conversion problem, solar cells are used for many
scientific and technological applications. Some of
them are:
o Artificial satellites and probes, like mars orbits,
use solar cells as the main source of energy
o Radio broadcasting or TV relay stations in remote
areas use solar cell panels as for its transmission.
This is because in remote areas, we may not find
power transmission line as it is expensive and
commercially viable.
o Traffic signals, electric watches, calculators and
many toys are fitted with solar cells.
o solar cell panels are being used to produce
electricity for the proposes of street lighting,
operating water pumps, for domestic and
agricultural works in remote/rural areas.

21. WHAT IS GEOTHERMAL ENERGY:
The heat inside the earth that can be
utilized as a source of energy under
favorable conditions is called
geothermal energy.
“geo” means earth and “thermal” means
heat.
Geothermal energy is the source of
energy that doesn’t derive its power,
directly or indirectly from the sun.
In other words, suns energy does not
power the flow of geothermal energy.

23. IMPORTANT INFORMATION:
The interior of the earth is very
hot. In the molten core lying deep
inside the earth, the temperature is
as high as 4000º C
Due to geological changes, molten
rocks called magma formed in the
deeper hot region of the earth’s
core get pushed upwards and
trapped in certain regions called hot
spot.

24. These hot spots are found at some
depths below the earth’s surface .
It is a tremendous source of heat.
When underground water seeps
down and comes in contact with the
hot spot, it boils and forms steam.
The steam so formed gets
compressed to very high pressure.
This steam has the ability to do
work.

25. HARNESSING OF GEOTHERMAL
ENERGY:
From natural geysers: At some
places, steam and hot water trapped
inside layers of rocks sometimes
force their way to surface through
cracks in the rocks. They gush out in
the form of huge fountains called
geysers.
These natural sources of steam in
form of natural geysers are used to
turn the turbines and generate

27. By drilling pipes : At some places,
steam trapped inside layers of
rocks is brought to the earth’s
surface by sinking pipes through
holes drilled up to the hot spots.
The steam which comes out at high
pressure through holes is utilized
to turn the turbines of an electric
generator to produce electricity.

29. ADVANTAGES OF
GEOTHERMAL ENERGY:
Geothermal energy is a renewable
source of energy. Since the interior
of the earth is going to remain hot
for millions of years, geothermal
energy is inexhaustible form of
energy.
It is a clean source of energy as it
does not cause any environmental
pollution.
The cost of production of electricity
is not much, i.e. the electricity
produced is inexpensive and
economical.

30. LIMITATIONS OF
GEOTHERMAL ENERGY:
 Only few sites have the potential of Geothermal
Energy.
 Most of the sites, where geothermal energy is
produced, are far from markets or cities, where it
needs to be consumed.
 Total generation potential of this source is too
small.
 There is always a danger of eruption of volcano.
 Installation cost of steam power plant is very high.
 There is no guarantee that the amount of energy
which is produced will justify the capital expenditure
and operations costs.
 It may release some harmful, poisonous gases that
can escape through the holes drilled during
construction.

32. TIDAL ENERGY:
 The alternate rise and fall in the water
level of the oceans and seas is known as
tides. The tides are caused due to the
gravitational force pull of mainly the
moon on the water and on the earth
itself.
 The energy obtained from the tidal waves
is known as tidal.
 The rise of ocean water is called high
tide.
 The fall of ocean water is called low tide.
 The tides can keep very huge amount of
water in movement and therefore they
provide a source of energy.

34. ADVANTAGES OF TIDAL ENERGY:
It is an inexhaustible and renewable
source of energy.
It does not cause any environmental
pollution .
It is not affected due to uncertainty
of rainfall.
It does not produce any harmful
waste .
It saves our valuable fossil fuels as it
does not require any fuel for its
production.
Once the tidal power plant is
established, it has low maintenance

35. LIMITATIONS OF TIDAL WAVE
ENERGY:
 Limited scope: Tidal dams cannot be established
everywhere. There are very few sites around
the world which is suitable for building tidal
dams to harness tidal energy.
 Small scale power generation: The rise and fall
of sea water during tides is not enough to
generate electricity on a large scale.
 High maintenance cost: The sluice gates and
blades of the turbines are exposed to salty
sea-water, so they need a high level of
maintenance , so the cost incurred in its
maintenance is high.
 Valuable output: There is variation in the tides
during the daytime so the power generation is

38. SEA-WAVE ENERGY:
 The energy associated with the sea waves
is known as sea wave energy.
 The waves are generated by the strong
winds blowing across the sea. It actually
happens when the strong winds travel
across the sea, the surface of the sea
causing waves.
 These fast moving huge waves have a lot
of kinetic energy in them.
 The kinetic energy possessed by the huge
waves near the sea-shore can be trapped

39. DEVICES TO TRAP WAVE ENERGY FOR GENERATING
ELECTRICITY:
 Oscillating water column
 Wave capture devices
 Wave profile devices
 These are the three main devices to trap energy for
generating electricity.

43. ADVANTAGES OF WAVE ENERGY:
No costs for energy
No waste products
Significant amount of energy can be
produced
Low running cost
Help to reduce reliance on non
renewable resources.

44. DISADVANTAGES OF WAVE
ENERGY:
 Variable energy supply
 Suitable location, where strong wave occurs
required
 Could be noisy
 Equipment should be strong to stand against
rough weather
 High initial capital costs
 Visual effect it near land, this could affect
tourism as well
 Can harm the marine ecosystem
 More expensive for the average consumer
compared to energy generated from non

45. OCEAN THERMAL ENERGY:
The energy available due to the
difference in the temperature
between the water at the
surface and water at depths is
called ocean thermal
energy(OTE)

47. WORKING OF THERMAL ENERGY
POWER PLANT:
 It can be operational when the temperature
difference between the water at the surface
and water at depths up to 2km is 20ºC or more .
The warm water of the sea is used to boil a liquid
like ammonia or a chlorofluorocarbon (CFC) in the
evaporator of OTEC plant to obtain its vapor.
 The resulting vapors of the ammonia liquid are
used to rotate the blades of the turbines. The
rotating turbine rotates the armature of the
generate electricity. The cold water from the
depth of the ocean is pumped up to the
condenser of the OTEC power plant. This cold
water is used to condense ammonia vapor into
liquid ammonia. The liquid ammonia is again taken
back to the evaporator and the process is

48. ADVANTAGES OF OTEC:
It is same as tidal energy and
wave energy, i.e. it is an
inexhaustible and renewable
source of energy, doe not cause
any harmful waste product,
saves valuable fossil fuels and
has low maintenance cost.

49. DISADVANTAGES OF OTEC:
It is same as tidal energy and
wave energy, i.e. it involves
investment, produces electricity
in small scale, high maintenance
cost and high cost of electricity
production.

50. GROUP MEMBERS:
 HANIYA HEDAYTH
 MALAVIKA RAJESHKUMAR
 SUMBAL BAHADUR
 SALMA DAULAT
 FATHIMA IRSHANA