Different sources of energy on Earth

All the forms of energy that we use everyday are stored in different ways in the energy sources. We need energy for all our activities from baking our favourite cakes to sending astronauts into space. The substance which produce heat on burning in air are called "Fuels". There are different forms of energy like mechanical, heat, chemical, electrical, light, sound, nuclear and so on.

Classification of Sources of Energy

The sources of energy can be classified on the basis of its occurrence, availability and physical state.

Classification on the basis of occurrence

Natural sources: Natural energy resources are those which are taken up by us from the nature. Eg: solar energy, wind energy, energy from water etc.

Synthetic energy: Man-made material used as sources of energy like chemical energy stored in the form of batteries that are used in calculators, remotes etc.

On The Basis Of Physical State

Solid: Firewood, charcoal, coal fall under the categories of solid fuels.

Liquid: A very commonly used fuel in our homes is kerosene. Other familiar liquid fuel are petrol and diesel.

Gas: Petroleum gas commonly known as LPG and natural gas used as CNG are two of the best known gases.

On the basis of availability

Renewable: A renewable sources of energy is one of which can be used over and over again. Wind, sun, biomass from plants and hydro power from water are all renewable sources of energy. These are inexhaustible natural resources.

Non-renewable: Energy sources, which gets used up and cannot be recreated in a short period of time is called a non-renewable sources of energy. These are also called exhaustible natural resources, and include fossil fuels like petroleum, natural gas and coal.

Fossil Fuel

Petroleum , natural gas and coal are called fossil fuel because they are formed over a period of millions of year by the action of heat from the earth's core and pressure on the remains of dead plants and animals.


Coal is a readily combustible black rock. Coal is one of the fuels used for cooking food. It produces lot of smoke and foul-smelling gases which causes air pollution.

Formation of coal: Coal are formed from plant remains buried under the earth's crust.


It is a dark coloured, viscous and foul-smelling liquid commonly called crude oil. It is found in rock formations in the earth. It is found at the moderate depth between the two layers of impervious rock.

Formation: With the help of giant rigs a hole is drilled in the earth's crust. When the hole reaches the rock cap, the natural gas comes out first with a giant pressure. After that petroleum starts flowing out.

Natural Gas

Natural gas is a fossil fuel that is found with petroleum in oil wells. It burns easily to produce heat and light.


For energy needs we must look for alternative such as solar energy, tidal energy, geothermal energy, wind energy etc. as the population is increasing and other fossil fuels are decreasing.


Author: stephin01 Jul 2012 Member Level: Bronze   Points : 0

This is very helpful to students . If you include more points about each it would be more helpful to students.

Author: Syed Musaddiq01 Dec 2012 Member Level: Gold   Points : 4

That is a very good and helpful article for students. And i appreciate your CONCLUSION "For energy needs we must look for alternative such as solar energy, tidal energy, geothermal energy, wind energy etc. as the population is increasing and other fossil fuels are decreasing". Yes there is an immediate need to look after the alternative sources of energy as there is a day to day net decrease in the fuel because of over population i.e. more demand an less supply and that is also the reason for the prices hikes.
So to cope up with this, we have to go for the alternative source like olar energy, tidal energy, geothermal energy, wind energy etc.

Author: Jagdish Patro22 Nov 2013 Member Level: Diamond   Points : 6

Nature has gifted mankind various forms of energy. The population growth, high standard of living and urban industrialization are the main reasons for the depletion of natural resources of energy leading to a necessary attempt for alternate energy resources like solar energy and geothermal energy. The environmental degradation, global warming, urban air pollution and acid rains have caused the depletion of natural energy resources like fossil fuel

The non-conventional sources of energy like wind, tidal, solar etc. were used in propelling ships, driving windmills for grinding corn and pumping water, etc. Thus these natural energy resources have helped the mankind before the advent of science and technology.
The exploration of alternate energy resources is very much required to meet the challenges of depleting energy conservation in India.
This article has well presented these natural energy resources .

Author: Dhruv06 Nov 2014 Member Level: Diamond   Points : 7

A very useful article indeed by the author. From this article I was able to brush up my knowledge on energy. To imagine a world devoid of energy resources is kind of nightmarish. Suppose one bad day all power sources suddenly come to a stop, then what will happen to our lifestyle? A lifestyle which has got so much used to modern amenities which all work due to one or the other energy resource. Simply unimaginable, is not it?

Its high time we start respecting our limited sources of energy, whether it is petroleum, coal or hydro-power. These sources can never be replenished and one day they are likely to come to an end. So we should not be extravagant in their use.

As everyone of you have mentioned about alternate sources of energy, its high time we devote our time and money in developing renewable sources of energy. Already solar and wind power are getting due importance. But there`s more to be done. Our country is blessed with bountiful of coastlines. Such places are ideal for setting up more and more windmills. Vast regions in Rajasthan and Gujarat are ideal for setting up solar plants.

Even households, offices and schools can give a push to solar power by installing solar plants on their rooftops. Still a long way to go friends, to secure our energy future.

Author: Hakimuddin Kuwakhedawala03 Apr 2017 Member Level: Gold   Points : 2

This is a very useful article. Sun is the ultimate source of energy. Energy is neither created nor destroyed, energy can only be converted from one form to another form. World is facing the problem of energy crises and to protect energy resources we must use alternative sources of energy.

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