We regularly report on biofuels -- from industrial ethanol facilities to home-brewed biodiesel -- because they're a big slice of the renewable energy pie. A new study from Cornell University and University of California-Berkeley directly challenges that, saying that turning plants such as corn, soybeans and sunflowers into fuel uses much more energy than the resulting ethanol or biodiesel generates.
"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," Pimentel said. "Further, its production and use contribute to air, water and soil pollution and global warming."
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," Pimentel said. "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.
We welcome healthy debate of this controversial topic. Feel free to use our online story response forum below to rebut, support or discuss this topic.
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As to the government study, remember that the DoE likes to justify its own existence (which is pretty shaky, considering their original charter was to oversee nucular 8) power), and the Ag Dept has always been a cheerleader and cartelization agent, so yes, their results are also questionable.
I think that the DOE et. al. treated a lot information about the process as an externality (i.e., "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.")
And what this new study does is consider all the information from beginning to end.
Cheers,
Neal
-- Tripp
http://www.ethanolrfa.org/pr020801b.html
In addition to providing a 34% positive energy gain, ethanol production utilizes mainly domestically available energy, such as coal and natural gas. Therefore for every 1 Btu of liquid fuel used to produce ethanol, there is a 6.34 Btu output.
The study cites increased corn yields, lower energy use in the fertilizer industry, and advances in fuel conversion technologies that have enhanced the economic and technical feasibility of producing ethanol. The study is an update of a previous USDA study completed in 1995, which demonstrated a 24% net energy gain.
If we're going to put huge subsidies--our tax dollars--toward something sustainable, why not into battery development or ongoing tax breaks so that the electric car can have a firm foothold.
The reasons for supporting ethanol in the past couple of years have largely been to get the US off of foreign oil. While celulose or microbial production of ethanlol might be more realistic and practical than crop-based production, neither would be as promising as an electric car that is charaged through renewables like solar or wind.
Cheers,
Neal
Somebody is lying or doing poor research or the scope of their research is not accurate.
Dave? What about that peer review process? Want to test your theories with somebody outside the Bush White house?
There are no benzenes, nor sulfur, nor nitrogen coming from the buring of oxigenated hydrocarbons like ethanol or biodiesel. Those pollutants only come from fossil fuels like gasoline and petroleum diesel. That means no air pollution.
Worse of yet, are those silly Europeans, who are paying $4.00 and $5.00 a gallon for fuel used to produce crops like rapeseed for biodiesel.
What you need is a professor of ECONOMICS to make this analysis, Dave!
The price of E85 fuel is always at least 20 cents lower than both regular unleaded gasoline and diesel.
The physics law of Conservation of Energy also prevents these biofuel producers from making the excess energy output (above the energy inputs) from nothing and then allowing them to sell that.
David Pimentel, professor of ecology, needs only to look up into the sky, at that strange ball of fire, to see where the surplus energy comes from.
Then the energy inputs and associated costs of production for biofuels would also play into the economics and should also bear out that these costs (for energy inputs), plus the crop and transport costs are lower than the price of the produced fuel. With a subsidy of only 20 cents per gallon and a price of $1.89/gallon for Ethanol, I do not believe it would be possible to stay SUSTAINABLE let alone even enter into the business of Ethanol production. The capital costs involved in building the production plant are also large.
Energy inputs to farming; to grow crops, produce fertilizers, irrigate, and harvest them surely are included in the price of the crop at market, or else the farming of those crops would not be sustainable. The energy inputs required to farm crops destined for use as biofuels is also surely not the entire cost covered in the price at market either (seed costs, land costs, labor costs, etc.).
Actually, most of those DOE reports do take the externalities into account when determining the energy balance. That's what precipitated my original post.
-- Tripp
It should also be noted that a gallon of gasoline doesn't just blow up out of the ground in Saudi Arabia and into your gas tank for free. There is an approximate 20% net energy loss to produce a gallon of gasoline from raw petroleum and transport it into a vehicle in the USA.
On balance, local ethanol production using local energy resourses to produce a cleaner liqued fuel for use locally seems like a better way to go, for our local economy and for our global environment.
I don't know who funds his research, but since most of what I've seen is anti RE of all flavors, I can only guess.
I'm a Cornell grad, and hate to see this guy trash our reputation, especially compared to all the real movers and shakers in the PV world who are also alums.
Absolutely right. I think we should sit around and wait until science can save us instead of actually taking a proactive position and doing what we can now.
This attitude drives me batty. Of course it is not a permanent solution. But hey, ya know what? It is an immediate implementation that helps.
Pimentel's study is so full of problems that it can't be taken seriously. As has been mentioned here, Soy is far from the optimal crop to extract oil from.
The livestock nutitional feed value of Distillers Grain (Wet and Dry) is better than raw corn. That should be factored into the energy balance.
The "other costs" of ethanol in subsidies and tax incentives all goes to major ethanol blenders such as gasoline refiners and to fuel users as a reduced fuel cost. It does not go to major ethanol producers or to farmers.
I as a farmer, I can produce biodiesel and ethanol within one year using solar energy, dirt, water, fertilizer and the financial management skills I acquired while attending Cornell University.
What's the price of a military tank or jet fighter without fuel? What's the value of your car when fuel prices escalate due to oligopolistic market forces from a crude oil industry with no competition from farmers?
One major flaw of Pimentels assertions, is that his studies assign all energy costs to components of the production cycle and do not discount those numbers for other materials produced in the process.
in his soybean biodiesel chart, he stated that it takes 5,556 kg of soybeans to make 1,000 kg of oil. He assigns all of the energy cost of 7,800,000 keal for growing the soybeans to the soy oil. For an energy cost of $1,117.42 this is 92% of the final energy costs of $1,212.16.
Yet, 82% of those soybeans are reduced to soy meal, which he writes off as "soy byproduct waste. Yet in his text he allows that one can credit 2.2 million keal to the meal produced which will result in an energy loss for the final product of 8%. However, his posted table of inputs for soy do not include energy credit for the meal.
Other good choices must surly exist. Why do we only focus on edible plants as ethanol bases? We aren't eating the fuel.
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