With steady increase in human population, urbanisation, industrialisation, research & development, demand for global energy has risen. The top five types of energy – oil, coal, natural gas (called fossil fuels), nuclear power and the renewable energy have been used to meet the energy demands.
However, oil has been the largest source of energy of the world with its dominance in the transport sector. In India hydroelectricity, natural gas and renewable sources too have been in use with oil leading the contribution.
Energy sources can be classified into two types viz, non-renewable and renewable.
