Josh-D. S. Davis

Xaminmo / Omnimax / Max Omni / Mad Scientist / Midnight Shadow / Radiation Master

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Ethanol net negative - research info
Josh 201604 KWP
David Pimentel, a professor of ecology at Cornell University who has been studying grain alcohol for 20 years, and Tad Patzek, an engineering professor at the University of California, Berkeley, co-wrote a recent report that estimates that making ethanol from corn requires 29 percent more fossil energy than the ethanol fuel itself actually contains.

The two scientists calculated all the fuel inputs for ethanol production—from the diesel fuel for the tractor planting the corn, to the fertilizer put in the field, to the energy needed at the processing plant—and found that ethanol is a net energy-loser. According to their calculations, ethanol contains about 76,000 BTUs per gallon, but producing that ethanol from corn takes about 98,000 BTUs.

For comparison, a gallon of gasoline contains about 116,000 BTUs per gallon. But making that gallon of gas—from drilling the well, to transportation, through refining—requires around 22,000 BTUs.

In addition to their findings on corn, they determined that making ethanol from switch grass requires 50 percent more fossil energy than the ethanol yields, wood biomass 57 percent more, and sunflowers 118 percent more. The best yield comes from soybeans, but they, too, are a net loser, requiring 27 percent more fossil energy than the biodiesel fuel produced.

In other words, more ethanol production will increase America’s total energy consumption, not decrease it.

Apparently, Pimentel was part of a 1978 Federal DoE study that showed big gaps. I've had trouble finding this report, though it might be buried in

Here's Pimentel's 1998 study showing a much larger gap between input and output energies:

Here's Pimentel's study with Patzek that's in Natural Resources Research, V14, #1, March 2005. This seems to take into account more uses for byproducts, etc. and is the source of the info above:

DoE has a chart which shows the names of other researchers who have various reports showing net-positive. This could be further expanded through research for comparison:

Here's a 2006 interview discussing the pro-ethanol bias and what's missing from the net-positive research referenced above:

Grist has further articles about the bias, but appears itself to be very biased the other way, especially in regards to ADM.

Gore says the Ethanol Tax credits weren't a good idea, 2010, a few weeks before the credits expire:

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I agree on all parts. I don't think the production efficiency for ethanol currently warrants federal mandates that fuel use ethanol, since the net is an increase in energy consumption.

If Ethanol production could be made more efficient, that would be awesome; however, I think that would require a GM crop with hither sugar content. I think sugar beets would be promising for the low cellulose and high starting sugar.

I still am holding my breath for algal oil. The key there is making the algae more disease resistant. That will be good for liquid fuel demands.

For the rest, I think wind & tidal are stopgap. They require a lot of space and pose hazards to wildlife and human recreation.

I think geothermal is good for the forseeable future.

I think large-scale solar is also good, especially with concentrators/tracking systems which have brought efficienty way up and cost-per-watt below $1.

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