Page 110 - Science - 5

Tidal Energy : This energy Depends upon the harnessing
the rise and fall of sea level due to tidal action. Dams are
constructed across a narrow part of sea and turbine
converts tidal energy into electricity.

Wave Energy : Kinetic energy of the waves of the sea are
used to rotate turbines. These turbines generate electricity.
Wind energy : A windmill uses moving air or wind to
produce wind energy.

Above sources of energy are present in plenty in nature.
We must use more of these sources of energy to meet our
energy demands. We don’t have to pay for these sources of
energy. The best part or quality is that these forms of

energy don’t cause any pollution.
Non-renewable Sources
Non-renewable SourcesNon-renewable Sources
Non-renewable sources are the sources which are present
in definite quantities in nature. Once they are used, they

can’t be reproduced or take a very long period of time

in reproducing. Petroleum, coal and other natural gases are non-renewable
sources and are called fossil fuels .
Petroleum is the most common source of energy. It is used to produce fuels

like petrol, kerosene, diesel etc. It is also a source of many other useful
products. Coal is also used extensively as a source of energy and heat. It is

used to create steam to produce electricity or to drive machinery. Natural gas
is used as a fuel for cooking and heating.
We should try to prevent these non-renewable sources from being wasted

uselessly.
Thermal Power Plants : Thermal power plants use coal, petroleum and

natural gas to produce thermal electricity. Energy transmission in this very
efficient. The system produce by burning the fuel run the turbine to generate

electricity.
CONSERVATION OF ENERGY

The economical use of sources of energy is called
energy conservation. The amount of energy
remains constant and energy is neither created nor

destroyed. Energy can be converted from one form
to another (e.g. : potential energy can be converted

to kinetic energy) but the total energy within the
domain remains fixed.

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