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Thread: Cornell ecologist's study ethanol and biodiesel not worth the energy

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    Cornell ecologist's study ethanol and biodiesel not worth the energy

    By Susan S. Lang


    Chris Hallman/University Photography
    Ecologist David Pimentel, shown here pumping gas, says that his analysis shows that producing ethanol uses more energy than the resulting fuel generates. Copyright Cornell University

    ITHACA, N.Y. -- Turning plants such as corn, soybeans and sunflowers into fuel uses much more energy than the resulting ethanol or biodiesel generates, according to a new Cornell University and University of California-Berkeley study.

    "There is just no energy benefit to using plant biomass for liquid fuel," says David Pimentel, professor of ecology and agriculture at Cornell. "These strategies are not sustainable."

    Pimentel and Tad W. Patzek, professor of civil and environmental engineering at Berkeley, conducted a detailed analysis of the energy input-yield ratios of producing ethanol from corn, switch grass and wood biomass as well as for producing biodiesel from soybean and sunflower plants. Their report is published in Natural Resources Research (Vol. 14:1, 65-76).

    In terms of energy output compared with energy input for ethanol production, the study found that:

    corn requires 29 percent more fossil energy than the fuel produced;
    switch grass requires 45 percent more fossil energy than the fuel produced; and wood biomass requires 57 percent more fossil energy than the fuel produced.

    In terms of energy output compared with the energy input for biodiesel production, the study found that:

    soybean plants requires 27 percent more fossil energy than the fuel produced, and sunflower plants requires 118 percent more fossil energy than the fuel produced.

    In assessing inputs, the researchers considered such factors as the energy used in producing the crop (including production of pesticides and fertilizer, running farm machinery and irrigating, grinding and transporting the crop) and in fermenting/distilling the ethanol from the water mix. Although additional costs are incurred, such as federal and state subsidies that are passed on to consumers and the costs associated with environmental pollution or degradation, these figures were not included in the analysis.

    "The United State desperately needs a liquid fuel replacement for oil in the near future," says Pimentel, "but producing ethanol or biodiesel from plant biomass is going down the wrong road, because you use more energy to produce these fuels than you get out from the combustion of these products."

    Although Pimentel advocates the use of burning biomass to produce thermal energy (to heat homes, for example), he deplores the use of biomass for liquid fuel. "The government spends more than $3 billion a year to subsidize ethanol production when it does not provide a net energy balance or gain, is not a renewable energy source or an economical fuel. Further, its production and use contribute to air, water and soil pollution and global warming," Pimentel says. He points out that the vast majority of the subsidies do not go to farmers but to large ethanol-producing corporations.

    "Ethanol production in the United States does not benefit the nation's energy security, its agriculture, economy or the environment," says Pimentel. "Ethanol production requires large fossil energy input, and therefore, it is contributing to oil and natural gas imports and U.S. deficits." He says the country should instead focus its efforts on producing electrical energy from photovoltaic cells, wind power and burning biomass and producing fuel from hydrogen conversion.
    http://www.news.cornell.edu/stories/...ostly.ssl.html

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    JetsInsider.com Legend
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    note that's Bush's whole reason for going to Brazil

    corn or sugar based ethonol is not a true alternative fuel - it looks like one but in terms of energy this research has confirmed that which has long been suspected. it's an oil additive not a substitute

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    So what is your opinion on the subject, Dawgg?

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    Quote Originally Posted by HDCentStOhio
    So what is your opinion on the subject, Dawgg?
    Solar Power. Clean. Efficient. Low Maintenance. Always available.

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    Quote Originally Posted by Jetdawgg
    Solar Power. Clean. Efficient. Low Maintenance. Always available.
    Maybe in the southern states, not here in the Upper Mid West!

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    Quote Originally Posted by MnJetFan
    Maybe in the southern states, not here in the Upper Mid West!
    The solar cells that I work with can run for up to 600 hours once fully charged. That's about 4 weeks with no sun.

    If we have no sun for that long we have a more serious concern than energy.

    I know that there are places in Alaska that get no sunlight for months at a time so special cases have to be considered.

    Solar power starts to work immediately upon connection to the battery.

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    Quote Originally Posted by Jetdawgg
    The solar cells that I work with can run for up to 600 hours once fully charged. That's about 4 weeks with no sun.

    If we have no sun for that long we have a more serious concern than energy.

    I know that there are places in Alaska that get no sunlight for months at a time so special cases have to be considered.

    Solar power starts to work immediately upon connection to the battery.

    the problem is Dawgg that if you go solar or wind, there aren't companies that can provide you with that energy since you don't need them to supply it to you going forward (after initial purchase)


    there is a problem with this article, if you used renewable sources of energy (wind, solar, thermal) to create the ethanol/biodiesel it is worth it since you aren't using any fossil fuel to create the energy needed to create the ethanol, it doesn't matter than you are using more energy than you create

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    Quote Originally Posted by Tanginius
    there is a problem with this article, if you used renewable sources of energy (wind, solar, thermal) to create the ethanol/biodiesel it is worth it since you aren't using any fossil fuel to create the energy needed to create the ethanol, it doesn't matter than you are using more energy than you create

    Yes, but what amount of "wind, solar, thermal" equipment will we need to produce 200 Billion gals of liquid fuel/yr?

    The bottom line is the consumer's pocketbook--whatever reduces the consumer's travel costs is what the consumer will buy. That's what happened in the early 1900's--biodiesel was used in diesel engines until about 1920 when the switch was made to petro-diesel b/c it was cheaper.

    Whether that can be reversed is debatable

  9. #9
    Quote Originally Posted by Jetdawgg
    The solar cells that I work with can run for up to 600 hours once fully charged. That's about 4 weeks with no sun.
    We need to power more than calculators.

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    Quote Originally Posted by Tanginius
    there is a problem with this article, if you used renewable sources of energy (wind, solar, thermal) to create the ethanol/biodiesel it is worth it since you aren't using any fossil fuel to create the energy needed to create the ethanol, it doesn't matter than you are using more energy than you create
    Great point. In any case, ethanol is not the ultimate answer. Nuclear energy and fuel cells are the future.

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    Quote Originally Posted by parafly
    Great point. In any case, ethanol is not the ultimate answer. Nuclear energy and fuel cells are the future.

    There's tons of helium-3 on the moon...we need to get up there, build a base, set up a coloNy and start mining that MF!!

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    Quote Originally Posted by jets5ever
    There's tons of helium-3 on the moon...we need to get up there, build a base, set up a coloNy and start mining that MF!!
    Sounds good, but can it be done cheaply enough to compete with petrofuels?

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    Quote Originally Posted by sackdance
    We need to power more than calculators.
    Solar cells power whole communities

    http://www.blog.thesietch.org/2007/0...bi-goes-solar/

    The 'decider' still has us on the prehistoric plan. Not only are they going to sell us oil, they will make more margin off of it since they will decrease their dependency

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    Quote Originally Posted by asuusa
    Yes, but what amount of "wind, solar, thermal" equipment will we need to produce 200 Billion gals of liquid fuel/yr?

    The bottom line is the consumer's pocketbook--whatever reduces the consumer's travel costs is what the consumer will buy. That's what happened in the early 1900's--biodiesel was used in diesel engines until about 1920 when the switch was made to petro-diesel b/c it was cheaper.

    Whether that can be reversed is debatable
    this message was brought to you by the large oil corporations of the world.

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    JetsInsider.com Legend
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    Quote Originally Posted by asuusa
    Sounds good, but can it be done cheaply enough to compete with petrofuels?
    are we including the price of war in these estimates? You could set up a colony on mars with the money we are wasting in Iraq.

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