Electricity, which can be aptly termed as the “back-bone” of our modern society, can be harnessed from a number of sources. These resources are further classified into two categories, namely, renewable and non-renewable. As the name denotes the non-renewable energy resources can be exploited only for a limited period of time. After a certain time period these resources will get exhausted or completely used up. On the other hand, the renewable sources can be utilized for generating electricity for an infinite time period, which means that these resources will never get depleted even if we use them for an indefinite period of time.

Non-renewable resources: These energy sources are actually obtained from the land in the form of oil, coal, and natural gas. Also termed as fossil fuels, these resources were produced from the remains of the prehistoric animals and plants in a natural fashion. These resources were produced by a natural process that lasted for a million years; they cannot be replenished once they are totally exhausted by mankind.

Renewable resources: Like their name implies, these resources can be renewed naturally even if they are utilized constantly for producing electricity. For example, the wind power, hydroelectric energy, biomass and solar energy are resources that cannot be completely exhausted by mankind. Moreover, unlike the non-renewable sources, these resources are not harmful and they do not produce any dangerous emissions when they are utilized for power generation.