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Scientists: Replacing Fossil Fuels with Biofuels Far Off, Benefits in Doubt

Last updated on 2012.08.22

The National Research Council has issued a report on the prospects for meeting our national biolfuels mandates over the next decade. The report, requested by Congress, is not optimistic:

  • We still lack viable technology for large-scale cellulosic ethanol production.
  • Scaling up cellulosic ethanol production may be so expensive that even government subsidies won't overcome investor hesitance.
  • Meeting our biofuel mandates will probably require converting cropland or currently uncultivated land to dedicated annual energy crops. The greenhouse gases emitted in that one-time conversion may offset any greenhouse gas savings gained in the long-term from replacing fossil fuels with ethanol.
  • Additional cropland dedicated to ethanol will further drive up land prices.
  • Even giving cellulosic ethanol the best cost estimates, it doesn't deliver energy more economically than oil at $111 a barrel.

Increased biofuel usage will also impact water availability. Among the crops available for ethanol production, sugar cane uses the least amount of water to produce each unit of energy (see p. 244, Table 5-10). However, replacing just 25% of each American's fossil fuel energy usage (based on 2010 consumption) would require just over 400,000 gallons of water per energy user. That's 10 times the amount of water my household drinks and washes in each year. Using a combination of corn and stover to produce that amount of ethanol energy would use about 750,000 gallons of water per person. Using switchgrass to produce the same amount of energy would require over 1.4 million gallons of water. The big hog among biofuel crops would be soybean biodiesel: replacing a quarter of your fossil fuel energy usage with soy diesel would use 4.9 million gallons of water. (Update: Water usage in the production of oil, even heavy oil, appears to be significantly less per energy unit produced.)

You can download the full 650-page pre-publication edition of the report here.


  1. John 2012.10.08

    Cory, thank you for this update on the biofuels. Cellulosic ethanol, outside of from carbon rich sugar cane, is not technologically or economically foreseeable in the near to mid-term future. They may never be viable. A better technological and economic plan for the waste wood in the Black Hills is renewable energy boilers, furnaces, and heaters - so long as we don't submit to the human foible of exponentially over building those and eventually create a fuel shortage.

  2. Bill Dithmer 2012.10.08

    Folks there are many many articles and discussions about this subject out there if you are willing to look for them. The answer is growing right here from descendants of seeds that were legal not to many years ago. The answer is hemp. It can be grown anywhere, used to make both kinds of fuel, doesn't take much water to make a crop, and would not need the more valuable land to grow such as corn or beans.

    The way we are producing ethanol now is a non working model of how to create a renewable source of fuel, the figures just don't add up to a better future for this country.

    Here is something to read that might help.

    It is important to understand that hemp provides two types of fuel; hemp biodiesel – made from the oil of the hemp seed, and hemp ethanol/methanol – made from the fermented stalk. To clarify further, ethanol is made from such things as grains, sugars, starches, waste paper & forest products, and methanol is made from woody matter. Through processes such as gasification, acid hydrolysis and enzymes, hemp can be used to make both ethanol and methanol.

    Now I dont agree with all of this but it is a place to start. Isnt it time to start living like it is the 21st century instead of the drug war 70s? Energy independence is a real possibility but only if we are willing to let go of our preconceptions of what is harmful and what is not.

    Think hemp.

    The Blindman

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