Page 85 - SST Class 05
P. 85
Electricity has become a common commodity now. It has numerous applications in our
daily life. Right from trimmers and blowers to fans and computers to refrigerators and
elevators, electricity is used widely. Even cars, buses and trains run on electricity
today. If there is no electricity for a few hours, people feel restless. Electricity poles in
towns and villages are the mark of progress and modern life today. It has become so
important in life that people have installed generators and inverters to get a
continuous flow of electricity in homes, offices, shops and other places.
Electricity is classified on how it is produced.
u Thermal electricity is produced by burning coal, mineral oil and gas.
u Hydroelectricty is produced from running water, by which turbines are turned.
u Nuclear energy is produced by nuclear power.
Clean Sources of Energy
Electricity is produced from different sources, like coal or water. We can classify
sources of energy into two types : conventional sources and non-conventional sources.
1. Conventional sources of energy use coal, mineral oil, natural gas and electricity.
This has certain serious limitations :
u The quantity of coal, mineral oil and natural gas is limited on the earth. We
cannot use them infinitely.
u These sources of energy cause a lot of environmental pollution.
2. Non-conventional sources of energy are also called alternative sources of energy .
They are clean sources of energy, like water, wind, sunlight etc. These sources have
the following characteristics :
u We can produce as much energy from these sources as we may want. For this,
we have to build dams, river projects, windmills and solar panels etc.
u The capacity to produce energy from wind, sunlight (solar energy) and tides
(tidal energy) is limited. It also depends on the natural factors, like presence of
rivers, seas and wind.
Gobar gas (biogas) energy is becoming viable on a limited scale now.
A gobar gas plant A windmill Solar panels Waves in the sea.
Sources of Energy 85
