Coal is used as a fuel in thermal power plant. Coal contains Chemical energy. Upon burning coal releases heat energy. This heat energy is used in thermal power plant to generate electricity. Problems associated with this type of power generation are:
Air pollution caused due to burning of coal: Burning of coal emits gases like carbon dioxide, sulphur oxide and nitrogen oxide which are harmful & toxic to health of living beings
Release of soot particles in the environment: Along with the gases released due to burning of coal, soot particles are released in the environment which can cause fatal respiratory problems such as asthma.
Coal is non-renewable source of energy. So, this method of power generation will put a limit on the availability of coal in future.