USDA study: Grass more efficient for ethanol than corn

William Atkins
Wednesday, 09 January 2008 19:05

Science - Energy

Besides producing more energy—more energy efficient—than corn-based ethanol, switchgrass-based ethanol produces far fewer greenhouse gases than corn-based ethanol—more environmentally friendly.

In fact, Vogel states that the production of switchgrass-based ethanol is expected to emit 94 percent  less greenhouse gases than the production of gasoline, while corn-based ethanol production produces 22 percent less greenhouse gases than gasoline. [Statistics provided by National Geographic magazine: "’Grass Gas’ Shows Promise as Superefficient, Clean Fuel"]

Vogal also states that switchgrass will not replace existing crop lands. Switchgrass can be easily grown on marginal lands (lands that are difficult to cultivate and lead to less profit for traditional crops such as corn, wheat, and soybeans). He says that over 35 million acres (14.2 million hectares) of marginal lands in the United States are currently not in use for existing crops.

The results of the USDA study (“Net energy of cellulosic ethanol from switchgrass”) were published on January 8, 2007 in the Proceedings of the National Academy of Sciences. The authors of the study are: Kenneth P. Vogel, M.R. Schmer, R.B. Mitchell, and R.K. Perrin.

Critics of biofuels state that they have the potential of causing environmental, agricultural, and societal problems. [as stated by National Geographic magazine: “Biofuels Could Do More Harm Than Good, UN Report Warns”] Such results by the USDA may help to lessen the criticisms of biofuels.

Some of the pros and cons on the use of switchgrass and other biofuels is found in the National Geographic article "’Grass Gas’ Shows Promise as Superefficient, Clean Fuel", which was referred to earlier.

A good article for further information and background on the USDA switchgrass study in Nebraska and North and South Dakota can be found in the Environment News Service article “Switchgrass Ethanol Yields Large Net Energy Gain.”