Conventional Sources of Energy:
1. Coal: Coal is one of the most important sources of energy and is being used for various purposes such as heating houses, as fuel for boilers and steam engines, and for the generation of electricity by thermal plants.
Coal has also become a precious source of production of chemicals of industrial importance of coal. It’ll continue to be the mainstay of power generation in India. It constitutes about 70% of the total commercial energy consumed in the country.
2. Oil: Like coal, petroleum is also derived from plants and also from dead animals that lived in the remote pasts. The exploitation of oil on a large scale started after 1960, the year when the first commercial well is reported to have come into existence. In India, efforts made by the Oil Corporation since the late 1950s have led to the identification of a number of oil deposits both offshore and onshore.
3. Natural Gas: Natural gas is also emerging as an important source of energy in India’s commercial energy scene in view of the large reserves of gas that have been established in the country. It has also been produced in the earth’s crust by a similar process as petroleum. It is also a combustible fuel. Natural gas also makes a significant contribution to the household sector.
4. Atomic Power: Atomic power involves the use of exothermic nuclear processes from radioactive elements like uranium generating huge amounts of heat. Atomic energy is produced by atoms. The term was denoted by Ernst Rutherford (1903). It is the source of nuclear power, which uses sustained nuclear fission to generate heat and electricity.
Non-Conventional Sources of Energy:
1. Solar Energy: Solar energy involves the harnessing of heat energy in a photovoltaic cell. It is the most readily available energy. Most of the renewable energy is ultimately “Solar energy” that is directly collected from sunlight. Energy is released by the Sun as electromagnetic waves.
2. Wind Energy: The origin of wind energy is Sun. When the sun’s ray falls on the earth, their surface gets heated up, and as a consequence, uneven winds are formed. The kinetic energy in the wind can be used to run wind turbines but the output power depends upon the wind speed. Turbines generally require wind in the range of 20km/hr.
3. Water Power: The power that is derived from the energy of falling water. Energy in the water can be harnessed and used in the form of motive energy. Since water is about 1000 times heavier than air, even a slow-flowing stream of water can yield a great amount of energy.
4. Small Hydropower: This is a non-conventional and renewable source and is easy to tap. Quantitatively small volumes of water with large falls and quantitatively not too large volumes of water with small falls can be tapped. This force of flowing and falling water is used to run water turbines to generate electricity.
5. Geothermal Energy: geothermal energy is generated and stored on the earth. Approximately 20% of the geothermal energy originates from the formation of the planet, while the rest 80% comes from the radioactive decay of minerals.
Geothermal energy is a very clean source of power. It comes from radioactive decay in the core of the earth, which heats the earth from the inside out. Thus the energy/power can be extracted owing to the temperature difference between hot rock deep in the earth and relatively cool surface air or water. It is required for this purpose that the hot rock should be relatively shallow, so it is site-specific and can only be applied in geologically active areas.