Power plant workers begin by heating the fossil fuel. Because coal is the cheapest to burn, it is used most often. Natural gas and petroleum may also be used as fossil fuels in power plants, but they are typically used less often because they are more expensive.
The burning fossil fuel heats water, turning it into steam. The steam travels into a turbine with thousands of blades. When the steam pushes these blades, the turbine shaft rotates at high speeds. The generator, a collection of highly wound coils, lies at one end of the turbine shaft. The rotation of the turbine causes the coils to turn, creating an electromagnetic field. Electrons begin to move; this flow of electrons is electricity.
When energy is first generated, operators transform it into the higher voltages (around 4,000 volts) used for economic transmission. When the energy approaches domestic areas, it is transformed down to a safer 100-250 voltage system.
