A study published by Science Expressed and discussed on Grist concludes that growing biomass for electricity production, and then using it to run electric vehicles, is more effective per acre than growing crops to produce liquid biofuels for internal combustion engines. This is true even if the liquid fuels are so-called ‘second generation’ or cellulosic biofuels, which it is hoped will provide an improvement over the poor climate change and energy security benefits of fuels like corn ethanol. The study estimates that the miles of travel enabled per acre are 81% greater when growing biomass for electricity, compared with cellulosic ethanol.
It seems like the most probable path to de-carbonized transport is the conversion of all short and medium-range vehicles to electric power, with liquid fuels reserved for vehicles that must travel long distances, aircraft, and vehicles operated in remote areas. Producing energy from biomass has another potential advantage, if carbon capture and storage (CCS) proves viable. By adding CCS to biomass-fueled power plants, net reductions in the atmospheric concentration of carbon dioxide could be achieved.
In time, it seems likely that the many government policies promoting the widespread use of biofuels were an ineffective response to both concerns about climate change and about energy security. In particular, ‘mandates’ that a certain fraction of vehicle fuels be biofuels do not necessarily do a good job of aligning outcomes with climate change objectives, since they are insensitive to both the lifecycle emissions associated with the fuels and to the economics of producing them.