A team of USDA Ag Research Service (ARS) and University of Nebraska-Lincoln (UNL) scientists say switchgrass, when used for cellulosic ethanol, yielded more than five times more energy than required to produce the fuel.
In the current issue of BioEnergy Research, ARS Grain, Forage and Bioenergy Research Unit researchers in Lincoln describe their study, which examined the farm-scale production costs of switchgrass. The team contracted with 10 farmers in Nebraska, North Dakota and South Dakota to commercially grow switchgrass for five years, starting in 2000 and 2001. Throughout the study, the farmers recorded all costs for producing switchgrass biomass, from seed and fertilizer expenses to equipment and labor costs. Total baled biomass yields were recorded for each farm.
On average, switchgrass production costs were $60/ton. Two farmers with previous experience growing switchgrass were able to limit production costs to $39. They were among a group of five farmers whose production costs were $50/ton or less. That's something farmers elsewhere could probably achieve as they, too, gain production experience with switchgrass, the researchers suggest. Based on the $50/ton figure, and assuming a conversion efficiency of 80-90 gals./ton, the farmgate production cost of cellulosic ethanol from switchgrass would be about 55-62¢/gal.
The ARS agronomists expect production costs to decline as new, "ethanol-friendly" cultivars are developed.
-- ARS news release