ABC's of Electricity
What is electricity? Nobody
knows the full answer. But we do know that electricity occurs
naturally. Electricity happens when an outside force upsets the
balancing force between protons and electrons (basic elements of
every atom). Electrons in the atoms transmit an electrical charge
through solid matter, such as metal, to produce an ELECTRIC
You can't store electricity. Once you generate it, you have to
use it right away or it disappears.
How does an electric power plant
operate? Electricity is generated inside a power plant.
The power plant burns a fossil fuel, such as coal, natural gas or
oil, to produce a lot of heat. The heat is used to boil water. The
steam from the boiling water is used to spin a big fan called a
turbine. The turbine turns a big magnet inside a generator to
create and electrical charge. The electrical charge is captured in
wires that carry the power to your home or school.
Some power plants use the pressure of falling water to spin the
turbine, which turns the generator. This process is called
hydroelectric power. Still another way to make electricity is
called nuclear energy. Instead of burning fossil fuels, a nuclear
plant uses a material called uranium. When split into microscopic
pieces, uranium releases a large amount of energy, which is used to
boil the water to make steam.
How is power delivered?
(Transmission) Electricity leaves the generator as a high voltage
current and passes through a transformer, which steps up voltage
even higher, depending on the distance it must be transmitted. It
then enters a transmission station, which is a mat or grid
interconnected to many other transmission lines to create a network
of power. Next, it flows to a substation transformer where the
current is stepped down to lower voltage, for use by local areas.
From there, it travels from the substation to your neighborhood
through distribution lines. Finally it reaches the pole transformer
where it is again stepped down to 120-140 volts and flows into your
home on demand.
How is electricity measured?
Electricity is not easy to measure. It passes through electrical
appliances in a circuit or closed loop. If you have no electrical
appliances on in your home, very little power passes through the
circuit. As electrical devices are turned on, current must pass
through your home to drive them. Power companies measure the flow
of electricity in terms of a kilowatt hour. A kilowatt hour is an
amount of force (1,000 watts) passing through your meter over a
period of an hour.
Electrical pressure is measured in volts. Transmission wires
operate at high voltages - up to 500,000 volts - to help
electricity travel over long distances.