G98:
I'll do both the math and the googling.
Ethanol is no more a solution than McDonald's used fry-oil is for diesel. Oh, it is a nice idea, but it will never amount to but a tiny proportion of the entire need.
Just one of the studies:
http://www.news.cornell.edu/releases/Aug01/corn-basedethanol.hrs.htmlo An acre of U.S. corn yields about 7,110 pounds of corn for processing into 328 gallons of ethanol. But planting, growing and harvesting that much corn requires about 140 gallons of fossil fuels and costs $347 per acre, according to Pimentel's analysis. Thus, even before corn is converted to ethanol, the feedstock costs $1.05 per gallon of ethanol.
o The energy economics get worse at the processing plants, where the grain is crushed and fermented. As many as three distillation steps are needed to separate the 8 percent ethanol from the 92 percent water. Additional treatment and energy are required to produce the 99.8 percent pure ethanol for mixing with gasoline.
o Adding up the energy costs of corn production and its conversion to ethanol, 131,000 BTUs are needed to make 1 gallon of ethanol. One gallon of ethanol has an energy value of only 77,000 BTU. "Put another way," Pimentel says, "about 70 percent more energy is required to produce ethanol than the energy that actually is in ethanol. Every time you make 1 gallon of ethanol, there is a net energy loss of 54,000 BTU."
o Ethanol from corn costs about $1.74 per gallon to produce, compared with about 95 cents to produce a gallon of gasoline. "That helps explain why fossil fuels -- not ethanol -- are used to produce ethanol," Pimentel says. "The growers and processors can't afford to burn ethanol to make ethanol. U.S. drivers couldn't afford it, either, if it weren't for government subsidies to artificially lower the price."
o Most economic analyses of corn-to-ethanol production overlook the costs of environmental damages, which Pimentel says should add another 23 cents per gallon. "Corn production in the U.S. erodes soil about 12 times faster than the soil can be reformed, and irrigating corn mines groundwater 25 percent faster than the natural recharge rate of ground water. The environmental system in which corn is being produced is being rapidly degraded. Corn should not be considered a renewable resource for ethanol energy production, especially when human food is being converted into ethanol."
o The approximately $1 billion a year in current federal and state subsidies (mainly to large corporations) for ethanol production are not the only costs to consumers, the Cornell scientist observes. Subsidized corn results in higher prices for meat, milk and eggs because about 70 percent of corn grain is fed to livestock and poultry in the United States Increasing ethanol production would further inflate corn prices, Pimentel says, noting: "In addition to paying tax dollars for ethanol subsidies, consumers would be paying significantly higher food prices in the marketplace."
o The average U.S. automobile, traveling 10,000 miles a year on pure ethanol (not a gasoline-ethanol mix) would need about 852 gallons of the corn-based fuel. This would take 11 acres to grow, based on net ethanol production. This is the same amount of cropland required to feed seven Americans.
o If all the automobiles in the United States were fueled with 100 percent ethanol, a total of about 97 percent of U.S. land area would be needed to grow the corn feedstock. Corn would cover nearly the total land area of the United States.
An Another
According to the Renewable Fuels Association, 95 ethanol refineries produced more than 4.3 billion gal. of ethanol in 2005. An additional 40 new or expanded refineries slated to come on line in the next 18 months will increase that to 6.3 billion gal. That sounds like a lot--and it is--but it represents just over 3 percent of our annual consumption of more than 200 billion gal. of gasoline and diesel.
One acre of corn can produce 300 gal. of ethanol per growing season. So, in order to replace that 200 billion gal. of petroleum products, American farmers would need to dedicate 675 million acres, or 71 percent of the nation's 938 million acres of farmland, to growing feedstock. Clearly, ethanol alone won't kick our fossil fuel dependence--unless we want to replace our oil imports with food imports.
Note, that is
total farmland in use in 2005, not just farmland currently used to grow corn. This includes farmland not particularly suitable to grow corn. Such less-optimal acreage would require higher inputs of water, fertilizers, fuels, etc. than prime corn-belt acres.
Some References:Acres Devoted to Corn 2000
http://www.epa.gov/oecaagct/ag101/cropmajor.html Energy Conversion Factors:
http://bioenergy.ornl.gov/papers/misc/energy_conv.htmlUS Oil Consumption:
http://www.eia.doe.gov/neic/quickfacts/quickoil.htmlMATHCorn Crop Land (Acres) 7.27E+07
Gal Eth/Acre 328
Total Eth Max (Gal) 2.38E+10
BTU/Gal Oil 1.38E+05
BTU/Gal Diesel 1.31E+05
BTU/Gal Gasoline 1.15E+05
BTU/Gal Eth 7.57E+04
Oil/Eth Factor 1.82
Diesel/Eth Factor 1.72
Gas/Eth Factor 1.52
Eth Equiv to Oil % 55%
Eth Equiv to Deisel % 58%
Eth Equiv to Gas % 66%
US Oil Consump (bbl/day) 2.08E+07
US Oil Consump (gal/day) 8.74E+08
US Oil Consump (gal/year) 3.19E+11
% Oil Used for Transport 69%
US Oil Consump Trans (gal/year) 2.20E+11
% US Trans Oil Met by Eth from All Corn Acres 11%
% US Total Oil Met by Eth from All Corn Acres 7%
Eth Produced 2005 4.30E+09
Eth Proj Pro 2006 6.30E+09
2005 Eth as Pct of Total Oil 0.74%
2006 Eth as Pct of Total Oil 1.08%
2005 Eth as Pct of Trans Oil 1.07%
2006 Eth as Pct of Trans Oil 1.57%
I can email the spreadsheet to whomever is interested.