The various energy sources are classified into two main groups.
a) Non-conventional or renewable energy sources.
b) Conventional or non-renewable energy sources.
1.1 Non-Conventional or Renewable Energy Sources
These energy sources are available abundantly in nature and can be reused again.
The various non-conventional energy sources are as follows.
i) Solar energy ii) Wind energy
iii) Hydraulic energy iv) Tidal energy
v) Wave energy vi) Geothermal energy
vii) Ocean thermal energy viii) Biogas energy
ix) Biomass energy x) Fuel cells
1.1.1 Advantage of Non-conventional energy sources
The leading advantage of non-conventional energy sources are
1) They are abundantly available in nature.
2) They do not pollute the atmosphere.
3) They are available in large quantities.
4) They are well suited for decentralized use.
5) The plants using these sources have very less (theoretically no) maintenance cost.
1.1.2 Disadvantages of Non-conventional energy sources
The Disadvantage of non-conventional energy sources are
1) They are available at very low intensities are
2) These sources are available in nature during particular periods which is uncertain.
3) Less efficiency of the power plants.
4) High initial cost.
1.2 Conventional or Non-renewable Energy Sources
These are the energy sources which once used can not be recovered any more. They are depleting in nature.
The various non-renewable energy sources are
i) Thermal energy from a) Coal coke b) Petroleum products like petrol, Diesel, Kerosene etc. c) Natural gas.
ii) Nuclear Energy.
1.2.1 Advantages of Conventional Energy Sources
Following are the advantages of conventional energy sources.
1) Their efficiency is more.
2) Their initial cost is comparatively less.
3) Their intensities are high.
1.2.2 Disadvantages of Conventional Energy Sources
The disadvantages of Conventional energy sources are
1) Their running and maintenance cost is high.
2) They are depleting in nature.
3) They cause pollution to atmosphere by different means.
Comparison between renewable and non-renewable energy sources