Page 4 ^ ^ The Clarion \ Feb. 12, 20
Electricity: How it powers our modern lives
by Dr. Jim Reynolds
Faculty Contributor
Electricity drives our modem lifestyle.
It always surprises me how few people
understand where electricity comes from
and how it is generated.
There are two fundamental ways
to generate electricity. One of these,
photovoltaic cells, is still in its infancy.
It converts sunlight directly into
electricity when photons from the sun jar
electrons loose in
a semiconductor,
such as silicon,
creating an electrical
current.
Efficiency of
that conversion is
creeping upward
suggesting that
someday every
rooftop will
become an electrical
generating station.
Only a tiny fraction
of our electricity is
currently produced
by photovoltaic
cells.
The primary generation method requires
that a magnet be mechanically spun inside
a wire coil. When this occurs, electrons
in the wire are set into motion creating an
electrical current.
Almost all of our electricity is generated
this way. Numerous ingenious techniques
for spiiming magnets have been developed
by a lot of clever people.
Fossil fuel and nuclear power plants boil
water into steam and force the steam to turn
the blades of a turbine with its attached
magnet. Water flowing under a dam spins
a turbine.
Geothermal plants use natural pressurized
steam from within the planet to turn the
blades. Wind, wave, tidal, and ocean
current turbines extract natural energy to
turn the magnet.
It’s all electricity but which is best? Let’s
look at electrical space heating. The goal is
to bring air temperature up to 20°-22° C.
Using coal-fired electricity, this requires
that coal be extracted from the ground, often
causing immediate long term enviroimiental
destruction. It is then transported, usually
by rail, to a power plant where thousands
of tons of it are burned daily at up to 1500°
C so that it can heat water to 375° C where
it flashes to high-pressure steam.
The steam is blasted into a turbine,
generating the electricity that flows across
the wires to your heating unit where air is
heated to 20°-22°C.
In addition to being able to watch
American Idol in
the warmth of
our living rooms,
society is left
with tons of toxic
coal ash, air and
water pollution,
a degraded
landscape, and
an acidifying
ocean.
The
countryside is
shrouded with a
toxic dusting of
lethal chemicals,
primarily
mercury, that were released with the carbon
dioxide that results from burning carbon:
more than 3 ‘/2 tons of C02 for every ton of
carbon burned.
The world bums more than 6.1 billion
metric tons of coal each year. After blowing
steam through a turbine, once, at -35%
thermodynamic efficiency, most heat is
released into the atmosphere through
cooling towers at the power plant.
Although nuclear fuel avoids much of
the water and air pollution, it leaves behind
a lethal waste that needs to be closely
guarded and monitored for the next mflhon
years. Few offer their backyards as storage
sites. These are caveman approaches to
generating electricity.
One might be led to conclude that electric
heating is bad and should be baimed.
Not so! Think about that cold January
wind that pelted Brevard for most of
last month. That cold wind can turn a
wind turbine, converting wind energy
directly into electricity to heat your electric
heater with only a fraction of the waste
and virtually none of the enviroimiental
degradation.
Deniers scream that wind power will
kfll birds and bats. How many more birds
and bats are kifled by air pollution from
coal-fired plants? or from flying into
smokestacks?
The body count in wind farms is wefl
documented because these critters fall
where they get bonked. No body counts
are made of air pollution-related deaths
because air pollution kflls anywhere that
birds and bats breathe.
The death toll is probably at least an
order of magnitude higher than that in
the wind farms. We also know that in the
southeastern United States, which has the
worst regional air pollution in the country,
there are more than 20,000 premature
human deaths each year that are directly
related to air pollution.
Naysayers and deniers claim that wind
power is not economic—even though it is
the fastest growing sector of our energy
palette. I ask, “What the hell is so economic
about heating water to 375° C so that air can
be heated to 22° C?”
On top of that, who pays for the
enviroimiental cleanup? We do, through
cleverly hidden subsidies to the nuclear
and fossil fuel power industries, in our
tax bifl.
If our electric bflls reflected the tme cost
of using nuclear or coal-fired electricity, we
would be screaming at Congress to lower
our taxes by developing the renewable
energy field as fast as possible.
There is nothing requiring us to use up
afl of our fossil fuels before converting to
renewable energy. No one doubts that this
conversion will happen.
Fossfl fuels are not renewable, except
over geologic time. Thomas L. Friedman
is fond of quoting a Saudi Arabian oil
minister who said, “The Stone Age didn’t
end because we ran out of stones.”
see Electricity, p. 5