Energy – A
Primer
By Peter
Schwartzman
Getting enough
energy to sustain us figures to be a major focus of society in the foreseeable
future. As our wants continue to grow (here and abroad), we'll need greater and
greater allotments of energy. However, given concerns over impending climate
change and increased reliance on foreign energy sources, we need to be very
cautious about the energy path we take. In this respect, the next few years are
critically important because the decisions and directions we soon take will
undoubtedly shape the world our children inherit. While the pace that climate
change will take is uncertain, don't we need to consider if "rolling the dice"
is good policy, especially when alternatives appear to exist. Also, how much
longer can we rely on our military to secure sufficient quantities of foreign
oil and natural gas? How will we begin moving towards climate stabilization and
energy independence?
These
questions require our attention now. It is important that all of us grapple
with them, and not let a few deep-pocketed politicians decide without our
counsel. However, in order to do so, we need to understand some basic concepts
about energy. Surprisingly, our educational system generally gives us very
little to work with when it comes to understanding the ever important energy
system. And, unfortunately, the press doesn't give folks sufficient background
either, perhaps because the writers themselves have little preparation. In
light of this, let's cover some of the basics, clarifying a few things that
have perplexed me and sharing a few implications following from these basic
revelations.
One
of the more mystifying aspects of understanding energy is making sense of all
the terms that are used to represent it. Consider that BTUs (British thermal
units), joules, kWh (kilowatt hours), calories, therms, quads, foot-pounds, and
ergs are all different measurements for energy. All of these units have their
adherents/users but it is imperative that we are conversant with them and
understand how to convert from one to the next without great difficulty. For an
example that illustrates this, consider: If someone has fourteen 100-watt (W)
light bulbs in their house and they use them approximately half of the time,
how much energy will this require (and how much will this cost) for an entire
year? First, we have to understand what we mean by a 100W light bulb. It doesn't
have anything to do with how much light (measured in lumens) is released and
everything to do with how much energy (here in the form of electricity) it
takes to light it up. (This is why an efficient fluorescent bulb can emit the
same amount of light as a standard incandescent one while being of a much lower
wattage). But the unit of watt/watts is actually a power measurement, i.e., an
energy intensity or energy per time; it takes roughly a watt of power to pick
up an orange from the ground and put it on a kitchen table if one takes but a
second to perform the task; the same task drawn out over a longer time period
requires the same energy, but less power. So in twelve hours of use, a 100W
light bulb requires 1,200 W-hours, or 1.2 kWh, as you will see it listed on
your electricity bill. Fourteen such bulbs, over an entire year, will use 6132
kWh. And since the going rate for residential electricity in the state is
~$0.11 per kilowatt-hour (interestingly, the industrial rate is over 30% less
in Illinois), running these bulbs each day, for twelve hours will cost $675
annually (EIA). No wonder it pays to turn the lights off.
Yet
when we start to account for our collective energy usage, we often use other
units. Currently, annual per capita energy usage in the U.S. is about 340 GJ
(billion joules) or ~97,000 kWh. Extrapolating this to all 300+ million people
in the United States, it is determined that we, collectively, consume 102 EJ
(exajoules, exa- is used for 10^18). Typically this is written in terms of BTUs
(as shown in the figures) or quads. Since one quad is equal to 1.055 EJ, we
consume about 97 quads of energy each year, which is an amazing number when one
considers that the world's other 200+ nations combined only consume ~353 quads.
So, here in the U.S., we consume ~22% of all the energy, though we make up less
than 5% of the world's population.
Once
one gets familiar with the units, the next insight comes by way of
differentiating between energy forms. We either get our energy from fossil
fuels, radioactive materials, the Earth's core, or the Sun. While the Sun's
energy, as direct light as well as in some of its secondary forms—wind,
waves, and currents, is by far the biggest supplier of energy on the planet, we
humans rely heavily on the much less abundant form—fossil fuels.
Currently, about 80% of our consumption of energy comes from petroleum, coal,
and natural gas (40%, 23%, and 23% of the total, respectively; nuclear power
only provides 8% of all the energy used nationally (and 6% globally). We use
fossil fuels to drive our vehicles, transport ourselves via other modes, heat
our homes, power our machines, and fertilize and chemically-treat our fields.
We use electricity, on the other hand, to power many household appliances and
some industrial machinery. Nationally, though, the consumption of electricity
accounts for only ~12% of all the energy that we directly consume. (It actually
requires ~38% of all our consumed energy to produce this 12%, which leaves 62%
left for non-electric purposes. This is due to major inefficiencies that result
from converting raw materials—such as coal—into electricity.) Most
of our electricity comes from burning coal (52%), with the rest derived from
natural gas and nuclear power, each to the tune of between 15 to 21%. This
leaves only about 11% coming from the renewable sources such as hydroelectric
(~7%) and biomass, geothermal, solar and wind (combining for ~4%).
It isn't just that
we are using finite resources to fuel our society and economy, we've been on a
path of increased energy consumption for quite some time. For instance, energy
use in the United States has nearly tripled (up 194%) since 1950. Most of this
stems from the growth in population, but some is due to increases in per capita
energy consumption which is up 39% (from 1960 to 2000) (see figures). Thus
despite using increasingly efficient technology in many areas, our greater
demand for goods has more than offset the advances in efficiencies. Globally,
things are moving even at a greater pace. Developing countries in particular
are seeing their energy consumption rise much more quickly. While the "developed"
countries have actually seen per capita energy consumption level off in the
past 15 years, "developing" countries have seen it grow 42%. Over the same
period, China has seen its per capita energy use go up a whopping 73%, a
staggering figure given its population is over 1.3 billion now (more than four
times as large as ours) (WRI).
And
all these energy forms aren't created equal however. Not only do they have the
potential to produce different amounts of energy, they are distributed very
differently about the planet. In the former case, a pound of gasoline contains
about 27% more energy than an equivalent weight of natural gas, about 1.5-2.8
times more energy than coal, and yet less than half the energy contained in
hydrogen (Smil). This is among the reasons why it makes the most sense to use
gasoline in our cars (at least as compared to other fossil fuels). Though
hydrogen is very energy-laden, it is gaseous at room temperature and pressure
as well as very, very explosive. In the latter case, our lack of oil in this
country and abundance in places like Iraq, Iran, Nigeria, and Venezuela, make
for interesting (and often humanly devastating) foreign policy decisions.
These
energy forms all also come with different externalities, i.e., the additional
costs/damage bore by society and the environment in the extraction, processing,
distribution and use of a particular energy form. By burning coal, we put
mercury into the environment. Some of this we ingest when we eat tuna or
swordfish (well, almost any fish, actually). This can do irreversible harm to
our bodies, neurologically and immunologically. On the other hand, solar panels
typically require the use of heavy metals (such as, tellurium and selenium)
that also can do damage to life if ingested in high quantities; selenium is
actually consider a trace nutrient that appears to benefit humans who consume
it in their diet. So there is no completely "clean" energy source and one must
actually do the full cost analysis (which we don't do) to find out which is
preferred. The true cost of these energies must include these externalities. In
fact, the first thing we need to do is reassess our values and our priorities.
If we did, I don't think we would be talking about "clean" coal and nuclear
power as part of a healthy and secure energy future.
We've been on a path
of increased energy for quite some time. For instance, energy use in the United
States has nearly tripled (up 194%) since 1950. Most of this stems from the
growth in population, but some is due to increases in per capita energy
consumption which is up 39% (from 1960 to 2000) (see figures). Thus despite
using increasingly efficient technology in many areas, our greater demand for
goods has more than offset the advances in efficiencies. Globally, things are
moving even at a greater pace. Developing countries in particular are seeing
their energy consumption rise much more quickly. While the "developed"
countries have actually seen per capita energy consumption level off in the
past 15 years, "developing" countries have seen it grow 42%. Over the same
period, China has seen its per capita energy use go up a whopping 73%, a
staggering figure given its population is over 1.3 billion now (more than four
times as large as ours) (WRI).
What does one make of all these numbers?
Well, we are still dominated by fossil fuels both for our electricity as well
as energy in general. Their use results in carbon dioxide emissions that are
pushing the climate system to unknown tipping points (i.e., a point where
irreversible change will occur, such as the melting of an ice sheet or a
shutting down of the deep water circulation in the ocean). Additionally,
burning these fuels also produces carbon monoxide, a poisonous gas, as well as
other gasses and particulates that are dangerous to our lungs and other life
forms. A shift to renewables (as many have recommended) will greatly reduce
these atmospheric inputs but it will require a major change from things as we
now have them. Wind turbines are going up all around us and this trend is
expected to continue. If we can begin to manufacture turbines in this country
on a large scale, this won't only make wind energy a great environmental choice
but will produce tons of good paying jobs as well. A report just released by
the Center for American Progress, points out how a "$100 billion down payment
on a better energy future" will pay huge dividends for workers in the U.S.
(Pollin et al.).
With a serious commitment to renewable energies in the U.S., we should be able
to produce 45 quads of energy (or 46% of our current usage) by midcentury
(Pimentel et
al.). Much of the remaining energy needs can be obtained in the form of
future energy savings (conservation, i.e., using less and adopting more
efficient ways of doing things). These savings can come in by way of better
insulated homes, more car pooling, higher fuel efficiency standards, improved
public transportation routes, enhanced local food consumption, installation of
fluorescent or LED lighting, and the purchase of energy efficient appliances.
These
conservation efforts get at the core of one of our most serious issues we have
to deal with in the U.S.—our gluttonous energy usage. Not only do we use
huge amounts of it (in per capita terms, we use 91% more energy than the
Japanese, 88% more than the Germans, 6 times more than the mainland Chinese,
and 16 times more than people in India or Kenya (WRI)), we now also import
nearly half of the energy we use (see figure). Notice how quickly we have
increased the amount of imported energy, three-fold in just twenty years.
Clearly, this trend can't continue. Domestically, we have very little oil left,
so it seems we are going to have to change our ways, rather abruptly in fact.
Walking the climate change tight rope also doesn't seem wise. It is time to
change. So, be prepared to change. Welcome it. Cleaner air and fewer wars over
oil will be just two of the many positive benefits of such changes.
One
gadget that might inspire you and others to be more conscientious about
household energy use is called a Kill-A-Watt; it can be purchased for $20-$25
online. It allows you to see how much energy a given appliance is using (very
simply to, just by plugging it into the device and then into the wall). This
information can provide the visible feedback we need to make more responsible
and cost-effective decisions. Hopefully, this device will make its way into
some stockings this year.
Schwartzman's other Zephyr articles on Energy (all available
online):
"The sun: an answer to many of
our problems." 1/10/08.
with Tim Montague. "Continued Energy Woes or a Secure
Energy Future?" 8/31/06.
"Is nuclear the answer?" 5/26/05.
"Where has all the oil gone? Short
term chaos. When will we ever learn?" 1/30/03.19, 2001.
Works Cited
EIA. Energy
Information Administration.
(electricity rates) www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html
(annual reviews) www.eia.doe.gov/emeu/aer/overview.html
Pimental et al.
(2002) "Renewable Energy: Current and Potential Issues." Bioscience.
Pollin
et al. (2008). "Green recovery: A Program to Create Good Jobs and Start Building
a Low-Carbon Economy." Center for American Progress.
Smil, Vaclav. (2006)
Energy.
Oneworld Publications, 181 pp.
WRI. World Resources
Institute. earthtrends.wri.org
Peter Schwartzman (email: wordnerdauthor@gmail.com)
is associate professor and chair of the Department of Environmental Studies at
Knox College. Father to two amazing girls, Peter hopes that their lives will be
lived on a less-toxic, more just, more loving planet. A nationally-ranked
Scrabble¨
junkie, he is also the founder and maintainer of websites dedicated to peace
and environmental well-being (www.onehuman.org & www.blackthornhill.org) as
well as cofounder of The Center (thecenteringalesburg.org).
11/27/08