Turning plants such as sunflowers into fuel uses much more energy than the resulting biodiesel generates, according to a new Cornell University and University of California at Berkeley study.
"There is just no energy benefit to using plant biomass for liquid fuel," said David Pimentel, professor of ecology and agriculture at Cornell. "These strategies are not sustainable."
Pimentel and Tad W. Patzek, professor of civil and environmental engineering at Berkeley, conducted a detailed analysis of the energy input-yield ratios of producing biodiesel from soybean and sunflower plants (Natural Resources Research, Vol. 14:1, 65-76).
They found that sunflower plants require 118 percent more fossil energy than the fuel produced - at 118 percent they take much more fossil energy to grow than corn (29 percent), switch grass (45 percent) and wood (57 percent).
Costs are incurred in producing the crop, including production of pesticides and fertilizer, running farm machinery and irrigating, and grinding and transporting the crop. Additional costs are incurred, such as federal and state subsidies that are passed on to consumers.
And how do we measure the costs associated with environmental pollution and degradation? That includes killing of wildlife outside of a hunting season.
In this modern era of computer modeling it is not necessary to destroy wildlife and degrade land for experimentation.
Susan Fedelchak, Durango