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Fuel
Producing electricity starts with fuel, such as coal, oil, or natural gas. In fossil power plants, fuel
is burned to create heat. Uranium is used as the fuel in nuclear power facilities to create heat by
splitting uranium atoms inside a reactor vessel. And the forceful power of falling water is used in
hydroelectric plants. Regardless of what fuel is used, the process of producing electricity is basically
the same.
Power Stations
To produce electricity, an extremely hot fire is created by burning fuel inside a large furnace known as
a boiler. Water runs through the boiler in a series of pipes. As the water heats, it is turned into
steam under intense pressure. The pressurized steam is fed into a turbine where it spins a series of blades,
similar to a large fan. Spinning at speeds of up to 3,600 rpm or 1,000 mph, the blades are used to spin a
rotor inside a generator, which is a cylinder of copper wires. Magnets spinning inside the coil of wire
produce the electrical current that is transported to customers.
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Once electricity is produced, an extensive transmission and distribution system is used to ship it to homes
and businesses.
Transmission System
Transmission generally refers to the movement of electricity at high voltages over long distances.
From a power plant, electricity first travels to a transformer in a substation at the plant that boosts the
voltage up to 69,000 volts or higher to efficiently transport large amounts of power over long distances.
The electricity then leaves the substation along high voltage transmission lines. These transmission lines
are supported by large steel, wood or concrete structures, which form the electrical grid that provides a
super highway for electricity.
Substations
Substations are located a numerous points along the grid. Substations are different sizes and generally consist
of a small building and a fenced-in yard containing various sizes of transformers. Inside a substation
are various switches, transformers, circuit breakers, lightning arrestors and other equipment used to adjust
the voltage of electricity, monitor circuits and protect the electrical system from short circuits, overloads
and surges caused by lightning.
Distribution System
Electricity leaves a substation along distribution lines. Distribution lines transport electricity at 13,200
or 4,000 volts to businesses and neighborhoods. Distribution lines are normally installed above ground and
are supported by wooden poles, but also can be carried by underground cables.
Before reaching individual customers, the voltage again is reduced through a transformer located on a pole,
or in the case of underground service, at a transformer located on a pad. The electricity now is at the proper
voltage to operate equipment and appliances. The electrical circuits in most homes operate at 240 volts for
large appliances like stoves and clothes dryers, and at 120 volts for lights, televisions and smaller appliances.
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