Biofuels Or Bioelectricity? Miles Per Acre Are Compared In New Study
What is the most efficient way to use farmed crops to power our vehicles - biofuels or bioelectricity? Researchers at the Carnegie Institution for Science, University of California, and Stanford University studied these issues as well as their relative impact on the environment. Guess which one fared miles better per acre than the other.
"It's a relatively obvious question once you ask it, but nobody had really asked it before," says study co-author Chris Field. "The kinds of motivations that have driven people to think about developing ethanol as a vehicle fuel have been somewhat different from those that have been motivating people to think about battery electric vehicles, but the overlap is in the area of maximizing efficiency and minimizing adverse impacts on climate."
Lead author of the study Elliott Campbell of UC Merced, Chris Field, director of the Department of Global Ecology at the Carnegie Institution and professor of biology at Stanford, and David Lobell of Stanford's Program on Food Security and the Environment, published the results of their study yesterday in Science Magazine.
After performing a life-cycle analysis of bioelectricity and biofuel (ethanol) technologies, taking into consideration the energy produced and the energy consumed by each technology, the conversion of farmed crops into energy, bioelectricity was the clear winner, regardless of whether the crop was corn or switchgrass.
The researchers calculated that compared to use of biofuels for combustion, bioelectricity for battery-powered cars would deliver an average of 80 percent more miles of transportation per acre of crops. Additionally, conversion to bioelectricity would offset greenhouse gas averages more than 100 percent if switchgrass is used.
"The internal combustion engine just isn't very efficient, especially when compared to electric vehicles," says Campbell. "Even the best ethanol-producing technologies with hybrid vehicles aren't enough to overcome this."
The research may be clear on a few aspects of biofuels vs. bioelectricity, but the team strongly suggests that other factors need researching as well. "We found that converting biomass to electricity rather than ethanol makes the most sense for two policy-relevant issues: transportation and climate," said researcher Lobell. "But we also need to compare these options for other issues like water consumption, air pollution, and economic costs."