This dissertation deals with fossil fuels: coal, petroleum and natural gas. It covers the information on their reserves, explains the process of their extraction and the process of generating electric energy from them. The dissertation includes the data on the quantity of electrical energy generated in the years 1980, 2002 and 2012. It presents countries with largest consumption and largest production of electrical energy from fossil fuels. Coal is the most abundant fossil fuel and also the largest source of energy for the generation of electricity. The reserves of petroleum and natural gas are approximately the same. Natural gas is more commonly used for the generation of electricity than petroleum, which is mainly used as motor fuel.