Swithgrass to electricity, yes; corn to ethanol, no

"Independent of what kind of car you talk about, it is more efficient to produce electricity than ethanol," said study co-author David Lobell, an environmental scientist at Stanford. "That's surprising because ethanol gets all the attention."

Study: Electric cars may be more efficient than ethanol

By Michael Torrice
San Jose Mercury News (California), May 7, 2009

Ethanol from plants can fill up drivers' gas tanks, but people could drive 80 percent farther if we converted those crops into electricity, according to a new study by Stanford and University of California researchers.

The study, published Thursday in the journal Science, compares two of the leading fossil fuel alternatives. As state and federal agencies decide how to dole out billions of dollars in subsidies and design new environmental regulations, the study could play a key role in helping determine what the next generation of cars will look like.

"We now have the opportunity to develop new technology for future transportation infrastructure," said the study's lead author, Elliot Campbell, an assistant professor in the college of engineering at UC-Merced. "If that infrastructure has a big renewable energy component, we need to understand what the most efficient energy source is."

Unlike fossil fuels, plants can be replenished. Also, because the plants absorb carbon dioxide as the grow, they can reduce greenhouse gas emissions.

Because the enormous energy demands of America's vehicle fleet and the fact that farmland is limited scientists have wondered how to most efficiently produce energy from the acreage.

(More here. Thanks to Minnesota Central for the tip.)