Sources of energy

4. WAVE ENERGY

9. Tidal Energy
 This is another unlimited and
inexhaustible source of energy.
The Gulfs of Kutch is preferably
suited to build up electricity
from the energy produced by
high and lofty tides entering into
slender creeks.

10. Tidal Energy

14. Ocean thermal energy conversion (OTEC) is a way of getting useful energy from the world's oceans.
The sun shines on the oceans of the world and in the hot parts near the equator the water at the sea's surface
can be quite warm, sometimes as high as 30°C.
Many oceans are very deep and the water at depths of 1,000 meters can be around 5 °C.
If a pipe is put down into the ocean we can bring the cold water to the surface where we also have warm water
available.
The difference in temperature between the warm surface water and the cold deep water may only be around 15
°C. But we can build a machine called a heat engine, which can use this difference to generate power that can
be used by people that live in that place. A machine which can do this is called an OTEC machine which stands
for ocean thermal energy conversion.
Because the difference in temperature is small we will need to get large quantities of warm and cold water to go
through the machine to get a useful amount of work, but large quantities are available in the ocean.
It has been estimated that OTEC could give amounts of energy that are 10 to 100 times greater than the other
ocean energy source, wave power.

18. Geothermal energy
Geothermal energy is energy
obtained by tapping the heat of the
earth itself, both from kilometers deep
into the Earth's crust in volcanically
active locations of the globe or from
shallow depths, as in geothermal
heat pumps in most locations of the
planet. It is expensive to build a
power station but operating costs are
low resulting in low energy costs for
suitable sites. Ultimately, this energy
derives from heat in the Earth's core.

21. Nuclear Energy

22. How is Nuclear energy generated?
 It is generated by a process called nuclear fission.
(similar process is used in nuclear weapons)
 The nucleus of a heavy atom (ex: uranium, plutonium) is bombarded with low-energy
neutrons they split into lighter nuclei, this releases a tremendous amount of energy
X 10,000,000
This energy can be used to produce steam and further generate electricity

23. Another method of producing Nuclear
Energy
• Nuclear fusion is a safer method than nuclear fission
• Fusion means joining lighter nuclei to form heavier nucleus and energy
• It is difficult to use this method as it requires extreme conditions i.e, millions of
degrees of temperature and millions of pascals of pressure

24. Nuclear power in India
Despite India having many nuclear power plants, it
has capacity of only around 3% of total electricity
generation of our country
Some other industrialised countries
meet more than 30% of their
electrical power needs with this
method

25. Hazards of nuclear
power generation
 The major hazard is the storage and
disposal of spent or used fuels
 Improper disposal leads to
environmental contamination
 There is also a risk of accidental
leakage of nuclear radiation
The high cost of installation, high risk
of environmental contamination and
limited availability of uranium makes
large scale use of Nuclear Energy
prohibitive