By David Landes
With biofuels producers facing a finite amount of land which can be converted for production, researchers have begun to examine ways to maximize biomass’s “miles per acre”.
Writing in the May issue of the magazine Science, researchers explain that bioelectricity could provide an average of 80 percent more miles of transportation per acre of crops in comparison to cellulosic ethanol.
In addition, converting biomass to electricity to power electric cars provides twice as many emissions offsets per unit area of cropland.
The findings come from a life-cycle analysis of bioelectricity and ethanol based on data from the US Environmental Protection Agency (EPA), and stem from a look at both the energy produced by each option, as well as the energy consumed in producing both the vehicles and fuels.
The advantages from bioelectricity stem from the improved efficiency of electric motors and from the superior efficiency of combustion power plants relative to the chemical conversion process used in producing ethanol.
The researchers warn however, that even if their study favours bioelectricity over ethanol, there are several other factors, such as water consumption and economic costs, which need to be taken into account when choosing an energy strategy.