- Coal is a chemical substance resulting from the remains of plant material which were buried hundreds of millions of years ago; hence, it falls into the category of a fossil fuel. Coal is mostly made of the element carbon, but it also contains other elements including hydrogen, oxygen, nitrogen and traces of sulfur. There are several different types of coal, depending on the amount of carbon they contain and their physical characteristics, such as hardness.
- The coal used to generate electricity is known as steam or thermal coal. It is mined and trucked to the power plant where it is first pulverized into a powder made of fine particles. This step gives the coal a very large surface area so it burns more rapidly and efficiently. After being pulverized, the coal is fed into a special chamber and is burned. This burning process releases a very large amount of heat. The power plant uses this heat to boil water into steam.
- The steam turbine helps in the process of turning the heat energy of steam into electrical energy. This device is made of a rotating shaft known as a rotor, fitted with a large number of propeller blades which project outward from it. The very hot steam, moving at 1,000 mph, enters a chamber holding the turbine and hits the blades. The force of the steam pushing on the blades turns the rotor and starts it spinning very quickly.
- The end of the steam turbine rotor is attached to a large coil of wire which sits inside a huge magnet. As the rotor spins, it also turns this coil of wire inside the magnetic field. Due to a scientific principle known as Faraday's Law, the motion of the wire inside the magnetic field induces a very strong electric current inside the wire. This electric current is the output of the power plant and the end result of thermal energy derived from burning the coal.