Reply #42: OK, I thought that was were you were going with that.

[kristopher]

I'm on dialup so I won't read your unidentified "peer reviewed" source. As to your other claim that most studies support the conclusions of the USDA; that simply isn't true. There is certainly work out there that proceeds in the same vein, however the problem is the basic slant of the analysis itself makes it virtually useless as a tool for determining the allocation of scarce energy resources. By playing fast and loose with parameters to be considered these analysis look much more to be agenda driven conclusions rather than an honest attempt to 'distill' the essence of facts relevant to guiding policy making.

What I-r-squared did IS peer review on a nonpeer reviewed document that ethanol proponents are widely using as a basis for their claims that the programs are cost effective and worthwhile. So when you say you "aren't going to copy his technique" it sounds like you are basically dismissing peer review.


I've previously mentioned the fallacy of limiting the discussion to a direct comparison of fossil fuels (where you count the energy stored as if it were an input today) and more importantly in my mind, to the very obvious and probably deliberate truncation of the cradle to grave analysis well before the point of greatest waste - the miserable 12% efficiency of the Internal Combustion Engine.

The criticisms of the use of EROI as a measure are frankly the type of "science" I expect from the Bush administration. While some explanations on the use of EROI as a tool are appropriate, to disregard it in it's entirety in favor of analysis based on treating the energy inputs from eons ago as relevant while disregarding the idiocy of preserving ICE technology is a mind boggling choice that can only be explained by the accusation of writing to a predetermined conclusion. As far as I can tell, the only possible reason such a fallacious argument would be deployed would be to hide the obvious failure of current ethanol policies to make a meaningful contribution to solving our energy problems. With the BILLIONS of dollars in tax money and false markets at stake I suggest extreme caution in evaluating claims that support ethanol as a solution to to our transportation energy woes.


Here are a couple of responses to a journal Science article written with the slant you seen to support. I include these (and not those supportive of the article) because they deal with the scope of the analysis and the fatal weakness flows from writing towards a preselected conclusion. At the end is the link to the letters posted and another to the original article.

Science 23 June 2006:
Vol. 312. no. 5781, pp. 1746 - 1748
DOI: 10.1126/science.312.5781.1746

Letters
Energy Returns on Ethanol Production
In their Report "Ethanol can contribute to energy and environmental goals" (27 Jan., p. 506), A. E. Farrell et al. focus in part on whether biomass-derived ethanol fuel delivers positive net energy . Their analysis neither resolves nor clarifies the fundamental issues that make net energy important and contentious. First, in their comparison of ethanol and gasoline, they confuse EROI--a productivity index--with the energy efficiency of an oil refinery. Second, their use of energy break-even as a litmus test is a red herring; it is more crucial that EROI is high compared with competing energy sources. Exploration for domestic petroleum in the 1930s returned 100 Joules for each Joule invested; the EROI for oil production today is ~15:1 (2). Because the present EROI of fossil fuels is high, the ~90 net Quads (1 Quad = ~1 exajoule) delivered annually to the U.S. economy results from an investment of only about 10 Quads (2). To provide that same 90 net Quads from corn-derived ethanol would require an investment of 145 to 500 Quads (based on an EROI = ~1.6:1 to 1.2:1, implied by Farrell et al.'s fig. 1). The current transportation system cannot be maintained on a fuel system delivering only a 1.6:1 return. Third, the focus on petroleum inputs is too limited. Natural gas is often the principal input to biomass fuel production, but its future is no more certain than oil's; we already import more than 15% of what we use (3). Fourth, the authors ignore the energy cost of repairing soil erosion.

Finally, the one (speculative) result for an energy technology based on cellulose in fig. 1 implies an EROI of ~50:1. This (very uncertain) EROI indicates that this source of biomass could be potentially useful, but ethanol from corn remains too marginal to survive without heavy economic subsidy.

Cutler J. Cleveland
Center for Energy and Environmental Studies
Boston University
675 Commonwealth Avenue
Boston, MA 02215, USA

Charles A. S. Hall
College of Environmental Science and Forestry
Syracuse, NY 13210, USA

Robert A. Herendeen
Illinois Natural History Survey
Champaign, IL 61821, USA

References

1. C. J. Cleveland, R. Costanza, C. A. S. Hall, R. Kaufmann, Science 225, 890 (1984).
2. C. J. Cleveland, Energy 30, 769 (2005).
3. Official U.S. Energy Information Web page, eia.doe.gov.



In their Report "Ethanol can contribute to energy and environmental goals" (27 Jan., p. 506), A. E. Farrell and colleagues offer hopeful opinions about corn-based ethanol. Their analysis suggests that, since the ratio of ethanol produced to fossil fuel used is positive, ethanol should be further developed. If replacing oil is our goal, we must look at two parameters of this approach: (i) energy return on investment (EROI) including environmental impacts on soil, water, climate change, ecosystem services, etc.; and (ii) scalability and timing. Farrell and colleagues' most optimistic EROI of 1.2:1 (which does not include tractors, labor, or environmental impacts) implies that we need to produce 6 MJ of ethanol to net 1 MJ of energy for other endeavors. Thus, the yield of ethanol would not be 360 gallons per acre gross yield, but rather a mere 60 gallons per acre net yield, not even two fill-ups for an SUV. The entire state of Iowa, if planted in corn, would yield approximately five days of gasoline alternative.

To devote half the nation's corn crop to ethanol would require an input of 3.42 billion barrels of oil (almost half our current national use) to net 684 million barrels of "new" ethanol energy. We would also lose food and soil nutrients, suffer ecosystem damage, and use massive amounts of water for irrigation.

We need alternative energy. But ethanol from corn is neither scalable nor sustainable. Let's pursue better options.

Nathan Hagens
Gund Institute for Ecological Economics
University of Vermont
Burlington, VT 05405, USA

Robert Costanza
Gund Institute for Ecological Economics
University of Vermont
Burlington, VT 05405, USA

Kenneth Mulder
Gund Institute for Ecological Economics
University of Vermont
Burlington, VT 05405, USA




The methodological flaws in A. E. Farrell et al.'s Report "Ethanol can contribute to energy and environmental goals" (27 Jan., p. 506) are revealed in the authors' fig. 1b, which shows that motor gasoline has a negative net energy and the highest input/output ratio, while ethanol technologies have positive net energies and lower input/output ratios. These numbers imply that motor gasoline is the marginal fuel seeking to displace biomass fuels.

This contradiction is caused by inconsistencies in the boundaries that are used to analyze their energy balance. For motor gasoline, the authors add the energy content of the gasoline to the effort used to produce it. The energy used to produce motor gasoline is much less than its energy content--estimates for the total energy input/energy output ratio are about 0.06 (1).

For biomass fuels, the authors report only the petroleum input/output ratio. Other fuels used in the process should also be included; these cannot be assumed to be sustainable (as exemplified by natural gas shortages) The biomass fuels are not used as liquids--(much of the co-products are used to generate electricity), which also needs to be taken into account. Including these additional fuels raises the input/output ratio to 0.79 (ethanol today) or 0.82 (CO2 intensive). If the U.S. economy used oil with an energy input/output ratio of about 0.8, the energy equivalent of about 80 million barrels per day of oil would be used to generate the 20 million barrels per day of refined petroleum products that the United States uses outside of the oil sector.

Once the boundaries are made equivalent, motor gasoline has a much higher energy surplus and a lower energy input/energy out ratio than biomass fuels. This result matches the economic reality described by the authors' first paragraph--biomass fuels, not motor gasoline, need subsidies and tax breaks.

Robert K. Kaufmann
Center for Energy and Environmental Studies
Boston University
675 Commonwealth Avenue
Boston, MA 02215, USA

Reference

1. C. J. Cleveland, Energy 30 (no. 5), 769 (2005).


http://www.sciencemag.org/cgi/content/full/sci;312/5781/1746

http://www.sciencemag.org/cgi/content/full/311/5760/506