Conventional energy directly mean the energy source which is fixed in nature like oil, gas and coal. In other words conventional energy is also termed as non-renewable energy sources. Their use leads to increased greenhouse gas emissions and other environmental damage. Natural gas is a fossil fuel used as a source of energy for heating, cooking, and electricity generation. It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals. It is a non-renewable resource.