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Energy Alternatives:
Once we accept that the
next 100 years onwards will likely be very different from the last with respect
to humanity’s use of petroleum and energy, the question then must be asked, so
who are the contenders to replace to that cheap black stuff to which we’ve
become so addicted and will they be capable. The following is a the
short list of the pros and cons of the likely contenders to try and replace
petroleum as it becomes increasingly less viable in the this century: (But before we do that
we need to become familiar with a term called Energy Return On Energy Invested (EROEI).
EROEI is basically how much energy one has to expend in order to obtain a given
energy resource. To illustrate, I’ll use the numbers arrived at by Howard
T.Odum’s comprehensive study in the text “Environmental Accounting, Energy,
and Decision Making” (You may also want to check out www.oianalytics.com
for an alternative calculation).
For the period between 1950-70 oil had an EROEI of 40, but today it has an EROEI
of 8.4 (imported oil) to 11.1 depending on the source. The Fossils (Coal, Natural Gas, other hydrocarbons) Pros:
There is a good understanding of how to extract energy from them. Natural Gas
has an EROEI in most cases(6.9-10.3) comparable to oil, burns cleaner than oil,
and most automobiles can be converted to run on it. One quarter of energy
consumption in the U.S. is already accounted for by natural gas and there is
already some infrastructure to support it. Coal is the most abundant fossil
fuel, and the U.S. currently derives as much power from coal as it does from
natural gas. Cons:
Natural gas is also a fossil fuel and like oil, will also be subject to a peak
production period and decline. Many believe that peak period will come shortly
after that of oil, possibly within a decade or earlier. Natural gas is also
difficult to transport by ship. It would have to be cooled to -260 degrees
Fahrenheit (-176 Celsius) for a ship tanker journey. Coal mining and burning
causes even more significant environmental damage than other fossil fuels and is
inefficient in comparison to oil and gas. In addition coal’s EROEI, while
currently comparable to other fossils, is declining rapidly. Emissions from
fossil fuels will contribute to greenhouse gases and will speed up global
warming. “Shale Oil” or oil shale - isn’t really oil at all but Kerogen, a
waxy substance that can be made into oil - a process that will likely take more
energy that it produces and yield more pollution than using coal. Oil sands -
processing produces extreme amounts of waste water and is devastating to the
environment, plus oil sands yield less than half the net energy of conventional
oil. Nuclear (Fission,
Fusion, “Breeder” reactors, etc) Pros:
Humanity is already familiar with nuclear power to some degree though many
don’t use it. Has an EROEI of 4.5. It is not as dangerous as widely believed
though the cost in lives and health from a single accident can be enormous.
“Direct” costs are relatively “cheap” (that is if you fail to factor in
cost of waste storage, plant construction and safety, etc). Nuclear plants
produce about 20 percent of all U.S. electricity, and 12% of electricity
globally. There is no direct carbon dioxide emissions from the reaction itself. Cons: Nuclear fission is the process that is commonly used for the generation of nuclear power. Uranium is used for a typical nuclear reactor and must be mined in a process that is extremely dangerous, polluting, wasteful, and would likely be powered by fossil fuels which we obviously need to be getting away from. Plutonium is could also be used for nuclear reactors if it can be successfully made using “Breeder” reactors. Plutonium is also one of the most dangerous substances on the planet and “Breeder” reactors are unproven, prohibitively expensive, and unsafe. In addition the waste from nuclear power plants cannot be disposed of adequately and remains radioactive for thousands of years. In almost 50 years of use, no country has succeeded in building a permanent high-level nuclear waste repository. Nuclear fusion, on the other hand is a theoretical process that could produce huge amounts of energy but it has been “25 years away for 50 years”, and the conditions needed to make it possible are not currently feasible.
Pros:
No greenhouse gases; only direct products of reaction are heat and water.
Hydrogen fuel cells could enable decentralization of power production and could
be used to run vehicles. Cons:
Hydrogen is not an energy source but an energy carrier. There are no exploitable
reserves of hydrogen. Hydrogen has to be manufactured from fossil fuels and
hydrogen production uses more energy than the resulting hydrogen yields. There
is currently NO hydrogen infrastructure and creating one doesn’t seem like a
great idea due to the aforementioned reasons. In a nutshell the “hydrogen
economy” being sold as humanity’s next stage is more fantasy than reality. “The Renewables” - Hydroelectric (dams), Wind, Solar, Biomass, Biodiesel, Ethanol, etc Pros:
Hydroelectricity has an EROEI of about 10. Currently about 9% of U.S.
electricity is generated from this source, which represents more than 3 times
all other renewable energy sources combined. Worldwide hydroelectricity accounts
for 19% of electricity generation. Wind power has an EROEI of around 2 but has
virtually no negative environmental impact. Solar also has no negative
environmental effects and is obviously abundant. Biomass is basically short for
plant material, including wood, seaweed, peat, agricultural waste, and garbage.
Biodiesel is basically chemically modified vegetable oil and Ethanol is a
fuel-grade form of alcohol. Biomass, biodiesel and ethanol pollute less than
fossil fuels when burned. Cons:
Hydroelectric often cause environmental problems by ruining natural water
pathways and marine habitat. Also hydroelectric resources are saturated in the
U.S. and in many other parts of the world, meaning there are few plans or
options for new dams. There is very little infrastructure to support wind power
and for reasons of geography it will likely be difficult to use in many areas.
Solar has an EROEI of less than 1 using today’s technologies and there is
little infrastructure to support it on wide scale, as inadequate investment has
been made into research and development for a number of decades. Biomass has a
low and very variable EROEI, limited growth potential, and creates air pollution
when burned. Both biodiesel and ethanol probably require as much or more energy
in terms of fossil fuel than they produce. There may be a couple of
other energy sources that have been left out, but they are hardly developed and
at this point it doesn’t seem very likely they will be true contenders.
Furthermore, the known existing energy alternatives to oil, even combined,
simply won’t pick up the slack at our current way of living. Worst then that,
we are decades behind building the infrastructure to support them. The views and opinions expressed herein by the author do not necessarily represent the opinions or position of Playahata.com. |
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