Types and sources of energy

05 Sources of energy

Energy is the ability of a system to do work or to make things happen.
Energy can neither be created nor destroyed but it can be converted from one form to another.
The sources of energy are varied: electrical, chemical, mechanical, heat or thermal, nuclear and energy in the form of electromagnetic radiation, i.e. light.
Such sources of energy are tapped by living organisms for their survival.
Example, chemical energy is stored in the form of food which is converted to energy in the body.
A candle is a similar reservoir of chemical energy that has to burnt for useful energy.
Thus burning is a process of conversion of chemical energy to heat energy or light.
Energy is also a crucial component of economic infrastructure as it is the basic input that is required to sustain the economic growth.

A good source of energy is the one which would do a large amount of work per unit mass (or per unit volume), is cheap and easily available, is easy to store and transport, is safe to handle and use, and which does not cause environmental pollution.
Also, a good source of energy is economical

Sources of energy are of divided into two types
- Renewable sources of energy/Non-Conventional sources of energy.
- Non-Renewable sources of energy/Conventional sources of energy.

The sources of energy which have accumulated in nature over a very, very long time and cannot be quickly replaced when exhausted or consumed are called non-renewable sources of energy.
They are affected or exhausted by human activity. Non-renewable sourced of energy are dug out from the earth. They cause pollution as well.
There are different type of conventional source of energy
- Fossil Fuels
- Thermal Power Plants
- Hydro Power Plants
- Bio Mass
- Wind Energy

Those sources of energy which are being produced continuously in nature and are inexhaustible.
Such resources can be renewed or replaced and do not cause pollution to the environment.
They are not affected by human activity.
The renewable sources of energy are:
- Solar energy
- Tidal energy
- Sea-wave energy
- Ocean Thermal Energy
- Geothermal energy
- Nuclear Energy

Natural resources have continued to provide sources of energy since ancient times.
Wood was used during Stone Age extensively as fuel and coal in the Iron Age.
Similarly, petroleum is a major source of energy in the modern times.

Conventional	Non-conventional
The resources which have been in use for a long time.	The resources which are yet in the process of development over the past few years.
These resources are exhaustible.	These resources are inexhaustible.
These resources cause pollution as they emit smoke and ash.	These resources are usually pollution free.
These resources are very expensive to be maintained, stored and transmitted.	These resources are less expensive due to local use and can easily be maintained.
Examples- coal, natural gas, petroleum, and water power.	Examples- solar, biomass, wind, bio gas, and tidal, geothermal.