Now, however, a study run by Stanford biology professor Chris Field and published in Science magazine has revealed that burning trees or switchgrass in powerplants in order to create electricity is significantly more efficient than using the equivalent amount of biomass that could be harvested from the switchgrass fields directly in flex-fuel vehicles.
The study found that electricity generated from burning one acre of trees or switchgrass allows a small electric SUV to travel around 14,000 miles, while an acre of biomass used to create ethanol allowed the same vehicle to only travel around 9,000 miles.
While we may think of fuel efficiency mostly in terms of 'miles per gallon' these days, global food shortages and efficiency requirements are pushing us to also think in terms of 'miles per acre'. For the time being, electric powered cars are significantly more efficient in terms of the energy they use compared to ethanol powered internal combustion engines, making them more efficient in terms of how much land is required to facilitate power needs.
Despite the obvious efficiency advantage of electricity over ethanol, biomass for fuel does have some of its own advantages, including the fact that many electric vehicles are significantly more expensive than their ethanol-drinking internal-combustion counterparts. On top of this, ethanol refueling takes the same amount of time as current petrol systems, while electricity can take significantly longer.