Fuel or electricity?  New research says that producing electricity instead of ethanol is a more efficient use of available farmland.

In the paper published in the journal Science this week, Elliott Campbell from UC Merced and two fellow researchers showed so-called bioelectricity can increase the mileage by 81 percent per acre of cropland over what cellulosic ethanol can deliver. Overall, a small car can travel 15,000 miles on electricity produced but only 8,000 miles on ethanol.

Not only that, generating bioelectricity produces 108 percent more offsets of greenhouse gas emissions, the scientists said.

The debate over what is the most environmentally friendly way to power cars could intensify as biofuel makers struggle to commercialize their technologies while car companies devote more resources on electric cars. Will the transportation market be shrinking faster than expected for biofuel producers? Cellulosic ethanol is made from plants or agricultural wastes, such as corn cobs, instead of corn starch. It's supposed to be a better way to go than using corn, which also could be used for food and animal feed.

The researchers set out to figure out what is the best use of our available cropland given the idea of clearing forestland for growing crops – or replacing food crops with energy crops – has drawn strong criticism from not just environmentalists but also cattle ranchers and other businesses that see the conversion as a sure way to push up prices for food and animal feed (see EPA Denies Texas Ethanol Waiver).

The "food v. fuel" debate reached a new height last year, when food and feed prices shot up significantly while corn ethanol makers increased their output. Ethanol makers released studies to show that their industry wasn't to blame, while critics said otherwise.

report released last month by the Congressional Budget Office said higher energy costs and other factors in fact had a greater impact on the rising food prices than the rising price of corn as a result of expanded ethanol production between April 2007 and April 2008.

Corn prices contributed to roughly 10 percent to 15 percent in food price increases, the report said.

After analyzing the energy produced by both ethanol and electricity production and their uses, the researchers found that bioelectricity provides more mileage regardless of the types of energy crops.

The research is bad news for ethanol makers, who are engaged in fierce policy battles in California and Washington, D.C. over regulations that would require them to factor greenhouse gas emissions from converting land to grow crops for fuel production (see Feds Propose Controversial biofuel Mandate, Offer $800M to Boost Production and California Adopts Low Carbon Fuel Standard).

The issue isn't just about land-use issues in the United States. The belief is that replacing food crops with energy crops in the country would lead to forest clearing in other parts of the world for growing food. 

Other researchers have proposed finding ways to minimize land conversions by considering whether growing crops for animal feed is an efficient use of available land. A group of researchers, led by Lynd Lee of Dartmouth College, is carrying out a project that looks at this issue, among others. At a biofuel conference in San Francisco this week, he took on cattle ranching, which requires a lot of land, feed and energy to produce beef. He noted that feed from each acre can produce more meat from chicken and other poultry than from cattle (see Eat Less Beef, Make More Biofuels).