The following is response to an off-list inquiry made about an article based upon David Pimental's representations as to ethanols dis-economics. It might make better sense to read the original inquiry first, then the response.
Todd Swearingen ............................. Dear [snip], First, I would care to enquire as to what your relationship and interest to the study, Pimental and any other researchers may be. Second, a person need not be expert in any particular field to discern that Pimental's study is largely lacking in multiple areas. Due diligence is sufficient to reveal many of the flaws. You can take one look at the article, make one call to your nearest ag agent, put pen to paper and determine that his calculations are all too frequently derived from inflated assumptions, perspectives and allocations. One could start with the premise that the average gasoline powered automobile in the US only achieves a fuel economy of ~11.74 miles per gallon. That is gravely erroneous. One could continue with the premise that it takes 11 acres to grow enough ethanol to propel same vehicle 10,000 miles each year. At a national average of ~120 bushels of corn/acre, yielding almost exactly 2.5 gallons per bushel, Mr. Pimental suggests that it will take 7.16 acres to grow enough fuel to produce the 852 gallons that will be derived from the remaining 2.84 acres. This in itself does not jibe with Mr. Pimental's energy input/output ratios. One could also take into consideration the negative impact that Pimental gives to agricultural subsidies while attributing no weight to fossil fuels subsidies and the costs resulting from them. This is an uneven and inappropriate tactic. Apples to apples is the appropriate method, not pears to squirrels. One could point out that Mr. Pimental makes no effort to ameliorate the production cost of ethanol by including the principal co-products of corn-based ethanol manufacture - oil, soap stock, lecithin and brewers' grains. In fact, Mr. Pimental would like to leave anyone who reads his "study" or articles based upon his "study" believing that only ethanol is produced from corn, therefore all costs and energy inputs/outputs should be assessed soley against the ethanol fraction. This is bogus, which any statistician, bean counter, economist or 1st year middle school student knows. The declaration also is made that it takes 11 acres to feed seven Americans. It is obvious by such a claim that Mr. Pimental is at best deriving his numbers from a heavily impalanced, factory farmed, meat centered diet where the majority of the acreage is used to produce grains and other feed for livestock, not humans. This in itself shows a severe bias towards inflated numbers and gives one cause to question if total exports of agricultural products were subtracted from his equations prior to their concoction. Throw in this "whopper" for good measure. Total US dry land mass is 3,536,278 square miles, or 2,263,217,920 acres. Pimental's own numbers and those from the article include that the average auto travels 10,000 miles, consuming 852 gallons of ethanol (if E-100 powered), that the average acre produces 126.96 bushels of corn, that the average yield of ethanol per bushel is 2.58 gallons, that the energy ratio is 1.70 to 1.0 (2.70 total gallons of ethanol per gallon produced) and that 97% of the US land mass would have to be planted in corn to meet this demand. (That's total land mass, not just arable land.) (2,263,217,920 x 126.96 x 2.58) / (832 x 2.7) = 330,009,090 "average" automobiles traversing the US, at 10,000 miles each. Oddly, the poplulation of the US is ~281,421,906 (year 2000 census, excluding service men and women overseas). Equally as odd is that US automobile insurers rate the average driver at ~10,000 miles annually. Subtracting from the population those youth not yet of driving age (under 16 years old) leaves you with 217,149147 persons old enough to drive. Subtracting the population older than 80 years of age leaves you with ~207,964,163 persons capable of driving the requisite 10,000 miles per year. That makes Pimental's numbers incredulously inflated by 36.98% - a rather large margin of miscalculation. Couple that with an obviously errant average fuel economy of 11.74 mpg when 20 mpg is closer to realistic. That's an approximate 41.32% total consumption error, bringing the total land mass "necessarily" covered by maize down to ~40.08%. Multiply that times the ~63.02% of actual drivers, rather than Pimental's 36.98% inflated number, and you come up with ~25.26% of the total land mass covered by corn, not the 97% that is mis-represented. (I wonder if Pimental would consider the difference "significant?") Couple all of these errors made by Pimental with fuel economy constantly being on the rise and you begin to see even more monumental reductions in Pimental's mis-representations. Aside from the fact that Pimental was heavily in error when he first presented his "study," he and it are even more irrelevant with each new hybrid or fuel efficient Jetta, Geo or other auto that goes into circulation. Yet numerous people off-handedly accept Pimental's "study" without much question. Why? Because he has a few letters dangling from his last name? As I said before [Snip], even a 1st year middle school student could legitimately poke holes in Pimental's work, which is largely what has been occurring since it came out. Maybe you know of a person or two who would be interested in a gravy masters or doctoral thesis? Hope the perspectives help. It's time for me to "clock back in." Todd Swearingen ----- Original Message ----- From: <[snip]> To: <[EMAIL PROTECTED]> Sent: Wednesday, August 28, 2002 7:17 AM Subject: ethanol economics > Hi Todd, > > Would you please review an article on a study by Prof. David Pimentel on the > uneconomical use of ethanol as a fuel? The article is at > www.unisci.com/stories/20013/0813012.htm. > > If you would please detail your response to the main points in the article, > I would greatly appreciate your expert viewpoints. > > Thank you, > [snip] > ------------------------ Yahoo! Groups Sponsor ---------------------~--> 4 DVDs Free +s&p Join Now http://us.click.yahoo.com/pt6YBB/NXiEAA/MVfIAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
