Cooperative Living February 2018 - 26

CloserLook | by Paul Wesslund, Contributing Writer
What's hot? The way you
get most of your electricity
W
e depend on electricity 24/7,
but have you ever wondered
how it's made, or where it
comes from?
To understand the basics of
something so important to modern
life, think about steam from a teakettle
and those magnets stuck to your
refrigerator door.
Magnetic metals in nature attract
each other because parts of the atoms
that make up those metals want
to match up with others. Those
restless atomic particles are called
electrons - and that's where we get
the word " electricity. "
In the early 1800s, a scientist in
England named Michael Faraday
noticed that when he rotated a metal
disk through the middle of a horseshoeshaped
magnet, he could get electrons
to flow together in an electric current.
Engineers soon took over and made
Faraday's process really complicated.
And really useful. Today, nearly all our
electricity comes from turbines that
spin a magnet inside a coil of wires.
One way to turn those turbines is
by heating liquid into steam that forces
the turbine to spin, using the same
principle that makes a teakettle sing.
When you boil water on your stove,
that liquid expands more than 1,000
times as it vaporizes. If you've ever
had your hand burned near boiling
water, you've felt the power that
steam produces.
The use of heat to spin a turbine
generates more than 80 percent of our
electricity using either coal, natural
gas or nuclear power.
Coal
Coal is dug from the ground,
either near the surface or from deep
underground mines, then is shipped to
power plants, often by train.
At the power-plant site, the coal is
24 | Cooperative Living | February 2018
stored in large piles on the ground until
it is ready to be burned. The coal chunks
are crushed into smaller pieces, or even
a powder, that is burned in a furnace.
The heat from that combustion is
used to turn liquid into the steam in a
furnace/boiler that spins the steam
turbine/generator producing electricity.
Large transformers at the plant boost
the voltage of the electricity (while
lowering the current and minimizing
line-loss potential) for shipment across
the country through tall transmission
lines. As it gets closer to where it will
be used, a substation of transformers
reduces the voltage to a level that can
be safely delivered to a smaller
transformer on the utility pole- or
pad-mounted transformer in your
yard, decreasing the voltage further
for use in your home.
As simple as that process sounds,
each step is extremely complicated in
order to make it as efficient and safe
as possible. The furnace burns the coal
up to 3,000 degrees Fahrenheit, and
the steam it produces gets hotter than
1,000 degrees. Coal contains harmful
elements that get captured and removed
through sophisticated pollution controls.
That environmental equipment can cost
as much as the power plant itself.
Coal plants produce about a third of
the nation's electricity.
Natural gas
Ancient plants and animals that died
long ago turned into coal, oil and
natural gas - that's why all three are
called fossil fuels.
Like coal, natural gas comes from
the ground, and it can burn in a way
that can drive a steam turbine or a
natural gas-fired combustion turbine.
Unlike coal, you can't hold it in your
hand - it's a colorless gas, like air, and
has to be transported by pipeline.
Natural gas can also be piped directly
Here are the basics on one
of the most important forces
in your everyday life.
into homes where it can be
burned in water heaters and stoves.
In a natural gas power plant, specially
designed combustion turbines burn
the gas to make them spin, generating
the electricity. The way natural gas
turbines work is similar to a jet engine,
and in fact they are a large, complicated
version of what you see hanging on
airplane wings.
Natural gas electric generation has
advantages over coal: The plants are
simpler, cheaper to build, require less
staff and they can be shut down and
powered up more quickly. Natural gas
doesn't contain as many pollutants as
coal, so fewer environmental controls
are needed. Natural gas burning also
produces less greenhouse gas. In the
past, natural gas was more expensive
than coal - until the 1990s when
fracking and other new drilling
techniques flooded the market. Natural
gas prices dropped dramatically and
many utilities are using it to replace
coal generation.
Natural gas plants now produce
about a third of the nation's electricity,
about the same as coal.
Nuclear
A nuclear power plant works basically
the same as a coal plant - making
steam to spin a turbine and generator.
The difference is that instead of
burning coal, heat from a nuclear reactor
heats the liquid into steam.
The basic fuel for a nuclear power
plant is uranium, which is mined from
the ground. It must then be formulated
into expensive and complex fuel
components for utility use.
A little uranium can last a long time,
making it a promising, incredibly cheap
power source. And it produces none
of the pollution or greenhouse gas
that comes from burning coal or natural
gas. But the concentrated radioactivity
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Cooperative Living February 2018

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