In earlier days, this was widely used in steam locomotives and the small coal nuggets were used as fuel for domestic water heating. Its primary objective is to generate heat through combustion. When this commodity undergoes a process during electricity generation, it is pulverized and burned in a furnace. The thermodynamic efficiency of the it to produce electricity by converting boiled water to steam and then further turning the turbines to generate electricity, has significantly improved. Almost 40% of the electricity produced in the world today is generated from Steam Coal.