What is electricity ?
Electricity is a form of energy that starts with atoms. You can't see
atoms because they're too small, but they make up everything around us.
There are three parts to an atom: protons, neutrons and electrons.
Electricity is created when electrons move from atom to atom. There are a
number of ways to make electrons move, but most electricity is produced
at power plants.
How do power plants work ?
Power plants that use water to make electricity are built near rivers.Dams are built across rivers to hold back the water. The water is then
directed through big pipes and it falls against the blades of giant
turbines. The turbines have blades on them that turn when the water hits
them, just like the blades of a pinwheel turn when you blow on them.
Once the water hits the blades, it returns to the river.
The turbine blades are attached to a big metal rod, and at the end of
that rod are large magnets. When the blades turn, they make the rod and
the magnets spin very fast. The magnet end is surrounded by heavy coils
of copper wire, and the spinning magnets cause electrons in the wire to
begin to move, creating electricity.
What happens to the electricity after that ?
It moves through wires into what's called a power transformer. The
electrical voltage (the strength at which electricity flows) is fairly
high and the transformer makes it even higher to help it flow through
wires called transmission lines. Those wires are attached to wooden or
metal poles that you see along roads and throughout communities.
All the wires are made of metal – usually aluminum or copper. That's
because metal is a good conductor – electricity travels through it
easily. By the way, water is also a good conductor, and because our
bodies are mostly made of water, electricity can travel through us
easily. That's not something we want to happen though, because if we
have electricity going through us we'll likely be seriously hurt or even
killed. That's why grown-ups warn you to stay away from high voltage
sites and not to stick your fingers in a wall plug.
Electricity travels fast – about 310,000 kilometers per second! If you
moved that fast, you could probably make several trips around the world
in the time it takes to turn on a light!
Sometimes, when electricity has to travel a long way it gets a little
weaker as it moves along the lines. It needs a boost (like you need food
to replace the energy you've burned after playing outside all day).
That's where substations help. Substations are large box-like power
transformers that sit in fenced-in areas. You'll see signs on the fences
that say high voltage – stay away and it's really important that you
obey those signs (remember what you read about electricity being able to
travel easily through your body).
How does electricity get into my house ?
When wires reach your house, another transformer on the power pole
makes the electricity just the right voltage so you can use it safely.
The wire is connected to a meter box that keeps track of how much
electricity is being used. There are wires in your house connected to
plugs, also called outlets. These outlets let you plug in your boom box,
television set, or any thing else electrical. What an amazing journey
electricity takes to get to your home !!
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