Energy is required to perform various activities in every field. Heat and electricity are two different forms of energy. The most common sources of generating heat and electricity are firewood, coal, petroleum and natural gas. These sources are called conventional sources of energy.
Firewood is primarily used for cooking and heating. However, it is not a very convenient and eco-friendly source of energy. Collecting firewood and cooking with it is time consuming and also burning firewood releases carbon monoxide in the air. This results in air pollution and higher levels of greenhouse gases. Firewood is also the main cause of deforestation.
Fossils are remains of plants and animals that were buried under the earth for millions of years. Coal, petroleum and natural gas are fossil fuels as they are formed from fossils.
Coal however, has its own set of disadvantages. Apart from being bulky to transport, it is also a source of pollution. The major coal producing countries in the world are China, the USA, Germany, Russia, South Africa, and France. In India, the major coal producing areas are Raniganj, Jharia, Dhanbad and Bokaro in Jharkhand.
About 80% of coal is mined from the Damodar Valley.
Petroleum is another important conventional source of energy. The word petroleum means rock oil and is found between layers of rocks in the form of a thick black liquid.
In its raw form petroleum is called crude oil which is drilled from oil fields located in off-shore and coastal areas. The major petroleum producing countries in the world are Iran, Iraq, Saudi Arabia and Qatar.
A major advantage of petroleum is that it can be easily transported in tankers. Natural gas is another fossil fuel that is traditionally used as a source of energy. It is found with petroleum deposits and is released when the crude oil is brought to the surface.
Electricity is also generated from the energy of flowing water. The energy derived from flowing water is called hydropower. The electricity generated from hydro power is called hydroelectricity. Norway was the first country in the world to develop hydroelectricity. The leading producers of hydro power in the world are Paraguay, Norway, Brazil, and China.
The fossil fuels are limited in stock and hence it is important to conserve these fossil fuels.