Sources of energy


Energy is everything that we see and feel on the planet because, as the saying goes energy can neither be created nor be destroyed,  energy is present in some of the other forms in all the living and non-living entities. Some of the areas of focus in this section are, what is energy, from where the energy is produced and how it is transferred. One should also understand is energy visible? Is there energy crisis in the world? Why a single form of energy cannot be used for all the purposes (for example electric current for every purpose). If energy can neither be created nor be destroyed why do we need to worry? and why there is a crisis? 


Sources of energy across the world 

Energy can be derived from many sources such as petrol, diesel, sunlight, coal, etc (see an example of a chart showing energy sources by percentage across the world). The largest source of energy that is freely available in the sunlight and in fact it is the least used source too. Following image shows the percentage distribution of various energy sources in India.

On a day to day basis, energy is used for a number of purposes. Our body needs it for biological processes such as digestion, respiration, cardiac activity, metabolism, and excretion. Country`s economy relies upon how well the energy sources are used for commercial and industrial purposes. Countries like India depends predominantly on various energy sources for agriculture. In addition to these, domestic purposes like cooking, washing, ironing, grinding require a lot of energy. In the outdoor setup, it is also used for lighting, transport, running machines etc. Different forms and levels of energy are needed for different purposes. Some of the characteristics of a good source of energy are enlisted below. 

  1.  A source should yield a maximum amount of energy per unit volume or mass.

  2. It must be easily convertible to various forms.

  3. Affordable, cheap and easily available.

  4.  It must be very safe to handle.

  5. It must not cause serious effects on our environment.

  6. It should be easy to store and transport.

  7. It must be less combustible.

There are two major sources of energy, namely the conventional sources of energy and the Non-Conventional sources of energy. Let’s discuss each in detail.


Renewable and non-renewable energy forms

Renewable energy

Non-renewable energy

This source can be used again and again and it won’t get over.

This is a form of  limited source and cannot be used again and again

These are non –conventional or not traditional forms so, lots of technology needed to use them.

They are usually traditional forms or the conventional sources of energy that are being used from ancient times.

Examples – Energy from the sea, Geothermal energy, Nuclear energy. Solar energy and Wind energy are Renewable sources but are Conventional sources.

Examples – Fossil fuels like coal and petroleum, biomass like wood. Wood can be considered a renewable resource if grown in proper quantity though it is a conventional resource.


The exploitation of  energy sources

The world is witnessing a never seen shortage of energy. This is closely linked to a lack of regulatory control over the usage of resources. Many of us are exploiting the sources for commercial purpose for the greedy and self- gain. Everyone should understand the fact that natural resources are not limitless and over-usage can bring a state of irreversible loss.


Energy  crisis in India

1. With over a billion population, the consumption of energy in India is very high when compared to many developed economies. With the advent of many technological innovations, new machinery, and new production units the demand for energy has further escalated high. Apart from domestic usage, commercial usage is increasing because of urbanization and industrialization. Currently, India generates more than 65% of its total electricity by using non-renewable sources of energy such as coal, gas, and oil which means, we are not using non-replenished and natural sources such as solar energy properly.

2. In our country, commercial energy makes up about 38.5%,. Oil constitutes 71.2% in household sector, 83.99% in transport, 61.8% in agriculture, coal (44.5%) and electricity (47.6%).

3. India has good reserves of coal energy but it is not being used for domestic purposes at present.






Course List