|This page was inspired by an article published in Science about Ethanol on 2006 January 27.
Ethanol's Energy Return on Investment: A Survey of the Literature 1990-Present, by Roel Hammerschlag, Institute for Lifecycle Environmental Assessment, P.O. Box 22437, Seattle, Washington 98122, in Environ. Sci. Technol., 40 (6), 1744 -1750, [2006 Feb 8]
"Various authors have reported conflicting values for the energy return on investment (rE) of ethanol manufacture. Energy policy analysts predisposed to or against ethanol frequently cite selections from these studies to support their positions. This literature review takes an objective look at the disagreement by normalizing and comparing the data sets from ten such studies. Six of the reviewed studies treat starch ethanol from corn, and four treat cellulosic ethanol. Each normalized data set is also submitted to a uniform calculation of rE defined as the total product energy divided by nonrenewable energy input to its manufacture. Defined this way rE > 1 indicates that the ethanol product has nominally captured at least some renewable energy, and rE > 0.76 indicates that it consumes less nonrenewable energy in its manufacture than gasoline. The reviewed corn ethanol studies imply 0.84 < rE < 1.65; three of the cellulosic ethanol studies imply 4.40 < rE < 6.61. The fourth cellulosic ethanol study reports rE = 0.69 and may reasonably be considered an outlier."
Comments: I am especially amused by the author's invention of the democratic method of science. Hammerschlag and Nathaniel Greene, a senior policy analyst for the environmental group Natural Resources Defense Council, which provided funding for Hammerschlag’s study, see 10 studies and all except 2 support their desired outcome. So they just write off the two "outlier" studies without troubling themselves to see what underlying assumptions might have led to different outcomes. [Ed.]
Paraphrasing Bob Hirsch in his most recent talk, making ethanol from corn is a process by which a certain amount of energy in the forms of natural gas and diesel fuel
are used to create an equivalent amount of energy in the form of ethanol, with the primary output being money from government subsidies.
Ethanol Can Contribute to Energy and Environmental Goals, by Alexander E. Farrell, Richard J. Plevin, Brian T. Turner, Andrew D. Jones, Michael O'Hare, Daniel M. Kammen, Science Vol. 311. no. 5760, pp. 506 - 508 [2006 January 27]
"To study the potential effects of increased biofuel use, we evaluated six representative analyses of fuel ethanol. Studies that reported negative net energy incorrectly ignored coproducts and used some obsolete data. All studies indicated that current corn ethanol technologies are much less petroleum-intensive than gasoline but have greenhouse gas emissions similar to those of gasoline. However, many important environmental effects of biofuel production are poorly understood. New metrics that measure specific resource inputs are developed, but further research into environmental metrics is needed. Nonetheless, it is already clear that large-scale use of ethanol for fuel will almost certainly require cellulosic technology."
Comments: Reading the details of this study, one discovers that the authors have assumed that the fossil fuel processing to yield one hundred units of ethanol energy includes 40 units of coal and 30 units of natural gas, plus some oil and other sources. What's the net yield from photosynthesis? "Only 5 to 26% of the energy content is renewable."
For more details, please review
- Looking at Biofuels and Bioenergy, LETTERS edited by Etta Kavanagh in Science, Vol 312 [2006 June 23]
Take special note of "THE METHODOLOGICAL FLAWS IN A. E. FARRELL ..." and
"IN THE NET-ENERGY ANALYSIS IN THEIR REPORT “Ethanol can contribute to energy and environmental goals” (27 Jan., p. 506), A. E. Farrell et al. do not (i) define the system boundaries, (ii) conserve mass, and, consequently, (iii) conserve energy. Most of the current First Law net-energy models of the industrial corn ethanol cycle are based on nonphysical assumptions and should be discarded...."
- The Real Biofuel Cycles, a thorough report on the flaws in this Junk Science article, by Tad Patzek, an Engineering Professor at UC Berkeley.
- More on biomass potential. More on ethanol.
- World’s Forests Continue to Shrink [2006 April 4]
- A poem, The Builders, from The Seaside and the Fireside, by Henry Wadsworth Longfellow
(1807-1882), comes to mind under the circumstances. [Ed.]
Editorial, in the same issue of Science: Getting Serious About Biofuels by Steven E. Koonin, Science [2006 January 27]
"Credible studies show that with plausible technology developments, biofuels could supply some 30% of global demand in an environmentally responsible manner without affecting food production."
Comments: Please explain what "credible" means in this context? Does it mean that Koonin doesn't want readers to question his conclusion? [Ed.]
|After seeing a rant that was circulated to slander wind energy, I asked wind energy expert Paul Gipe to set the record straight. [Ed.]
Junk Science (Rant):
"Wind - Facts or blowing hot air? by L. M. Schwartz, The Virginia Land Rights Coalition [2004 March]
Government agencies and the wind industry have successfully portrayed wind-generated electricity as "green" and as a price-competitive, potentially significant alternative source of power which could reduce dependence on 'dirty' fuels.
Comments: Grid Integration of Wind Energy, by Paul Gipe [2006 March]
While wind generated electricity may make sense in some circumstances, industry and government claims for its widespread use are not currently supported by sound science or economic analysis of costs v. benefits....
Despite the multi-billion dollar expenditure of taxpayer funds by government and the "renewable energy" industry during the past 35+ years, the results have proven disastrous in economic terms. The Department of Energy (DOE) and other federal and state agencies have spent over $40 billion on "energy research and development" and subsidies, not including private R&D costs, yet virtually nothing has been 'developed' that is technologically, economically or environmentally sound.
The subsidy of "green" energy, such as solar, geo-thermal, hydro, bio-mass and wind, has distorted the operation of electrical power markets, increased electricity rates to consumers, increased taxes at all levels of government, diverted resources from industry financed (private) research for more efficient and cleaner means of producing and distributing power, politicized energy production, and prevented or delayed bringing more base capacity on line to reliably meet present and projected increases in demand..."
"Availability factors are meaningful for generating units that are "dispatchable" (can be called upon to produce electricity whenever needed) but are meaningless for "intermittent" generating sources such as windmills which can produce electricity only when the wind is blowing within certain speed ranges....
"Electricity from wind turbines is of less value than electricity from "dispatchable" generating units because it is available only when the wind is blowing within certain speed ranges...."
"Grid integration of renewable energy, especially wind energy, is a controversial topic-and has been for nearly three decades. Frankly, I think the subject has been beaten to death and for my part the questions answered many times over. Nevertheless, those opposed to renewable energy continually raise the subject in the hopes that this is some silver bullet that will put wind and solar energy in its grave. As a consequence, renewable advocates ask me for help to rebutt the common myths about wind energy's "unreliability"."