♪♪♪
-Turn on, turn off.
Plug in, unplug.
Gestures we perform every day
whenever we need to.
Electric energy is such
an integral part of our lives
that we forget about it
in the end.
But just what is electricity?
To better understand
this phenomenon,
we need to think about the world at the atomic level.
Air, water, living beings,
and physical objects,
such as electric wires,
are all made up of tiny atoms.
Each atom has a nucleus
surrounded by electrons
that revolve around it much the
way satellites orbit the earth.
The electrons in certain metals
like copper
can easily leave their orbits.
These materials
are called "conductors."
What happens when an electron
escapes its orbit?
The electron simply moves over
to the nucleus of another atom.
And when electrons move,
it produces what we call
an "electric current."
But how can we get electrons
to move?
Here is a natural magnet.
Magnets have a north pole
and a south pole.
We can see the lines of force
in the magnetic field here.
When we bring two magnets
close together,
they can attract
or repel each other.
There's something
between the two of them
that allows this movement.
That something is
the magnetic field.
A little like what happens
between two magnets,
the magnetic field
has an effect on electrons.
When we wave a magnet over
a conductor like copper wire,
the magnetic field attracts
or repels the electrons.
This movement of electrons
is electricity.
So where does the electricity
we use every day come from?
Let's follow electricity
all the way back to the source,
the place it is generated.
Electricity comes from
the gigantic generating units
found in
hydroelectric power stations.
These generators operate on
exactly the same principle
as the magnet
and the copper wire.
Let's see how!
A generator
has two main components:
the rotor,
and the stator.
The rotor contains a series
of magnets that we call "poles."
The stator consists of
a number of copper bars.
To simplify things,
let's see what happens
with a single magnet
and a single copper bar.
Simply bringing the magnet
close to the copper bar
is not enough
to produce current.
Without movement,
there is no electricity.
Now let's see what happens
if we rotate our magnet.
When we rotate the magnet
next to the copper bar,
the magnetic field causes
a movement of electrons,
and hence, electricity.
Let's go back to our rotor.
It creates exactly
the same effect as a magnet
except that it is
made up of electromagnets.
An electromagnet is used when
a powerful magnet is needed.
It consists of a metal core
placed inside a coil
of electric wire.
When a current flows through
the electric coil,
a magnetic field similar to
that of a magnet is created.
The main advantage
of an electromagnet
is that the force of
its magnetism can be controlled.
The rotor has
several electromagnets.
The alternately attract
and repel the electrons
that are in
the stator's copper bars.
In this way,
the generator can power millions of light bulbs.
But how can we get a heavy rotor to rotate?
With a motor?
No, that would certainly
not be very efficient.
In Quebec, it is mainly
the mechanical force of water
that makes rotors rotate.
The water hits the blades of 
the turbine, making it turn.
To generate electricity,
Hydro-Québec thus uses
a renewable energy source.
The rotating motion of the
turbine also drives the shaft.
And since the rotor
is also attached to the shaft,
it rotates around the stator,
and makes the electrons move.
But these moving electrons
don't travel all the way
from the generating station
to your home.
In fact, electrons move through
wires in a domino effect.
One electron pushes another,
which pushes another, and so on,
until the electricity
reaches your home.
Electricity is
an invisible phenomenon.
We can't see it,
but we can measure it.
Power,
which is measured in watts,
depends on two phenomena:
voltage and current.
To give an analogy,
voltage is like the speed 
at which a car
is being driven on a highway.
Voltage is measured in volts.
Current can be compared
to the number of cars
driving past a milestone
on a highway at the same time.
Current is measured in amperes.
If you combine
voltage and current,
you get power,
expressed in watts.
Power can be compared
to a highway's capacity
to handle various numbers
of cars.
And if we measure how many cars have driven on the highway
in an hour,
we get the energy consumed.
Energy is the amount of power
consumed in a given time.
Let's take another example:
The power of a 25-watt
compact fluorescent bulb
corresponds to its ability
to provide light.
If that bulb remained lit
for four hours,
it would consume 100 watt-hours in energy.
After 40 hours,
the total consumption
would be 1000 watt-hours,
or one kilowatt-hour.
More than ever, electricity
is a precious source of energy.
Using energy-efficient products
like compact fluorescent bulbs
is a good way
to reduce consumption.
There are many ways we can
change our behaviour or habits
to save energy.
Every little bit helps.
Making wise use of energy
is good for all of us,
and good for the environment!
