Fossil fuels are produced from animals and plants that were living 300 million years back. Oil, gas, and coal are the common examples of fossil fuels. The term "fossil fuel" is used to describe these fuels because their source dates back to the prehistoric period. These fuels are mostly obtained in the form of deposits under the earth. Fossil fuels have chemical energy stored within them. When these fuels are burnt, the stored energy gets released and serves the purpose. Fossil fuels are used to meet around 85% of the total energy requirement of the world.
Origin of Fossil Fuels: An Overview
The biogenic theory gives an idea about the origin of fossil fuels. Algae and zooplankton that settled under the water bodies like sea or huge lake in the prehistoric period are the main source of petroleum. Anoxic conditions are required for the formation of petroleum. On the other hand, terrestrial plants that died in prehistoric period are the main source of coal.
Use of Fossil Fuels
Fossil fuels assume huge importance in the energy scenario of the world. Oil alone meets around 40% of the total requirement of energy. The distillate fuels derived from crude oil are extensively used for transportation, cooking, industrial production and many other purposes. Heating oil, turbo-jet fuel, kerosene, and diesel are some of the examples of distillate fuels.
Fossil fuels constitute the chief sources of electrical energy. The thermal power plants make use of coal for power generation. The power plants that use coal contribute 50% of the total demand of energy across the world.
Supply Constraint of Fossil Fuels
Unlike the renewable forms of energy, the sources of fossil fuels are limited. Owing to the increased demand of fossil fuels, world is going to face fuel crisis in future. This is the reason as to why the demand for renewable energy is increasing over the years. Efforts are also on to reduce the use of fossil fuels in order to check the emissions of greenhouse gases.