As
humans, we tend to bucket things into two categories: good or evil, hard or
easy, rich or poor, stupid or smart. The same could be said for how people
understand different energy sources: renewable energy or traditional energy,
green power or brown power, clean energy or dirty energy. However, such perfect
binaries don’t really exist, and the clean energy / “dirty” energy dichotomy is
no exception to this.
When you
think of clean energy, you typically think of renewable energy sources such as solar and wind — and you’d be
right! You’d also get a checkmark if you wrote nuclear energy on a test. But you’d probably get half credit if you
penciled in natural gas, depending on the person grading, since there’s obvious
debate whether fossil fuels can truly be clean.
At Chariot Energy, we believe clean energy is synonymous with renewable energy — energy that doesn’t emit greenhouse gases or other pollutants. Still, others claim that nuclear energy, natural gas and even clean-burning coal are on the cleaner end of the spectrum. In this article, we delve into the different sources of clean energy — including nuclear and natural gas — and ultimately why we believe “clean” should be synonymous with “renewable.”
We will
start by examining the 6 main sources of clean energy. Out of all energy
resources, we consider green power (solar, wind, biomass and geothermal) as the
cleanest form of energy. So, if we were looking at clean energy on a spectrum,
these would be farthest from “dirty” or emissions-heavy energy.
We’ll
then discuss natural gas, which some energy experts classify as a clean energy
source (but we don’t think it is). Finally, we’ll talk about one particular
energy source that we simply cannot bring ourselves to include. We share why
that is later in the post.
Our beautiful bread and butter, solar energy. We experience this amazing clean energy source through sunlight and heat, and we can utilize this energy to create electricity through technology like solar panels or concentrating solar power plants (reflective mirrors). We generate this electricity without any emissions or pollution, so it earns a checkmark.
Another
clean energy source, wind energy is technically
another form of solar energy since the sun is partly responsible for all
weather patterns on Earth. However, for the sake of how electricity is produced
by solar panels and wind turbines, they are considered two different forms of
energy.
Like
solar energy, power generated from wind turbines produces no air pollutants.
So, it’s an easy check on our list of clean energy requirements.
This is a really fun source of energy! Well, not fun, per se, but it’s nonetheless interesting. This form of renewable energy is created by living organisms such as algae, wood, crop residue. It can also come from food waste, landfills and fermented crops. The most common application is fuel for transportation and heating buildings.
It’s such
a versatile form of energy because, while it can and does generate electricity,
its most prevalent use lies in the creation of biofuels for transportation as a
replacement for fossil fuels. And since we need fuel for everything from our
cars to airplanes, bioenergy lowers the carbon impact on the environment. Check!
Unlike
water, solar and wind, geothermal energy isn’t derived from the sun. Instead,
it is energy in the form of heat from the Earth itself. Most often, geothermal
is used to heat and cool people’s homes.
To create
geothermal electricity, the Earth’s heat energy is used to boil water to create
steam. This steam then rotates turbines that generate energy. It’s similar to a
coal-powered power plant, but it’s run on the Earth’s heat instead of burning
fossil fuels.
Another
checkmark!
Again,
another source of energy technically powered by the sun, hydropower is fueled
by the water cycle. The sun evaporates water, which then forms clouds that then
drop rainfall and snow that create rivers, streams and other large bodies of
water. The famous Hoover Dam, the giant structure holding back the raging
Colorado River, is only one example of how hydropower is used today.
Hydropower
relies on the kinetic energy from flowing water and transforms it into
electricity through spinning turbines located in a moving body of water. Hence,
hydropower can be a large-scale operation like the Hoover Dam, or it can be
small-scale without a dam. Most importantly, this process doesn’t create
greenhouse gases when generating electricity.
Now,
we’re getting into more controversial territory. This is the test case for why
“clean” energy is difficult to define for some. Technically, nuclear energy is
emissions-free, and it is hugely efficient. One pellet of uranium fuel (approx.
1 cm x 1 cm) is the energy equivalent of approximately 150 gallons of gas or
17,000 cubic feet of natural gas. To put this in perspective, five grams of
this tiny pellet can produce enough energy to power a normal household for 6
months.
The counter
to that “clean” argument is that nuclear energy gives off radiation, which, if
improperly handled, could contaminate air and water. However, even with the
horrible outliers like Chernobyl and Three Mile Island, the risk of contamination
is small since there are so many safety systems in place.
So, is
this energy source truly clean? In our opinion, because of the waste created,
nuclear energy is not clean. However, we can’t deny that nuclear power significantly
reduces greenhouse gas emissions by replacing the need for fossil fuels.
Ultimately, you have to decide for yourself whether this one checks the clean
energy box.
This is easily the most disputed inclusion on our list. In fact, the Department of Energy doesn’t even list natural gas as a clean energy source. It’s under the fossil fuels section because, fundamentally speaking, natural gas is derived from dinosaurs, and it does produce greenhouse gas emissions, specifically methane, when burned.
So,
what’s the point of even considering natural gas on this list? According to the
U.S. Energy Information Administration, burning natural gas results in fewer
emissions of nearly all types of air pollutants than coal or petroleum products
to create the same amount of energy. It’s considered “clean” because it’s
technically “cleaner” than other fossil fuels and is the reason for its
explosion in popularity amongst energy generators.
However,
it definitely has drawbacks, specifically when you consider hydraulic fracking.
While we won’t get into the nitty-gritty details behind how this process works,
it’s essentially a low-cost way of extracting natural gas from rock. Fracking requires
a lot of water, which creates a lot of wastewater, and it’s been known to cause
earthquakes and contaminate water supplies.
Sorry, no
checkmark for you!
There
have been endless internet memes created about clean coal for a reason: It’s
the literal opposite of clean energy.
In
reality, clean coal is no different from regular coal. It’s merely a public
relations ploy designed to reshape public opinion on fossil fuels. Clean coal
is dubbed “clean” because coal plants can capture the carbon dioxide (CO2)
before it’s emitted into the air and bury it underground. The process is called
carbon capture and storage, and we’re all for it — when implemented correctly.
To whit,
carbon capture is a great way to tackle global warming, as it collects CO2
already in the atmosphere and puts it back into the earth. This is
essentially what plants do; carbon capture and storage is just a man-made way
of doing it.
What
we’re not on board with is terming
any aspect of the coal industry as “clean.” Coal creates significant
environmental impacts beyond just burning it to create electricity. This
includes mining, land erosion, acid rain, water pollution and much more.
This
doesn’t get a checkmark. We give it a big red “X” — the kind you feared from
your teachers in school.
The more
research you do into clean energy, the more confusing the term becomes. This is
why there’s such a need for an official definition of the concept. That’s why
we created one ourselves: Clean energy is any energy source that does not emit
greenhouse gases or other pollutants. Hence, nuclear waste isn’t clean by that
metric.
Well,
isn’t that convenient? By our definition, clean energy really is just another term for renewable
energy. Check!
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