Page 83 - SST Class 05

13 Sources of Energy

Energy and I

We need food as a source of energy for our body; much in a like manner, many of our machines need
energy. The sources of this energy are several, but as they cause pollution, there is need to find clean
sources of energy, so that we can enjoy the bounties of nature without causing risk to the environment
and our health.

We need energy in different ways. We need electricity to run the grinder or fan at
home. Vehicles run on petrol or diesel. Some machines run on coal. All these are
different sources of energy. Let us discuss their different types.

Coal

The first effective use of energy was found in the steam engine. It ran on coal or wood.
However, it gave a lot of smoke and pollution. Moreover, manpower was needed to
feed coal or wood to the engine continuously. This was the reason that need was felt
for more efficient types of fuel.

Even today, coal is used in
several industrial applications.
Thermal energy is also made
from it. It is found deep below the
surface of the earth from where it

is mined. The quantity of coal is
limited on the earth, so there is
need to conserve it. Also, it causes
a lot of environmental pollution A coalmine A factory chimney
in the form of smoke and dust.

Mineral Oil and Natural Gas

Petroleum was first discovered in America in 1857. Gottlieb Daimler saw it burn
brightly, and he thought that it could be used as a fuel. He invented an engine in 1885
which ran on petrol. Today, petrol is widely used in a variety of vehicles.

Sources of Energy 83