Researchers from Stanford University and the University of California, Merced, studied the lifecycle of plant-based electricity, or “bioelectricity,” and ethanol technologies to determine which delivered more miles of transportation with fewer environmental impacts. They concluded battery-powered vehicles that used electricity derived from biomass provided an average of 80 percent more miles of transportation per crop acre than internal combustion engine vehicles running on ethanol made from corn or switchgrass.
"The internal combustion engine just isn't very efficient, especially when compared to electric vehicles," Co-author Eliott Campbell of U.C. Merced said in a statement last week. "Even the best ethanol-producing technologies with hybrid vehicles aren't enough to overcome this."
A small SUV with an internal combustion engine can travel roughly 9,000 highway miles on the net energy produced from an acre of switchgrass, compared to nearly 14,000 highway miles for a small SUV powered by bioelectricity.
Electric cars fueled by bioelectricity avoid twice as many greenhouse gas emissions as ethanol-powered internal combustion engine vehicles, according to the study.
"We found that converting biomass to electricity rather than ethanol makes the most sense for two policy-relevant issues: transportation and climate," Co-author David Lobell of Stanford's Program on Food Security and the Environment said in a statement. "But we also need to compare these options for other issues like water consumption, air pollution, and economic costs."
In addition to Lobell and Campbell, the research team included Chris Field, a Stanford professor and director of the department of global ecology at the Carnegie Institution. The trio’s study appeared in the May 8 issue of the journal Science.
Switchgrass -- CC licensed by Flickr user AdsitAdventures.