Study Suggests Biomass Converted Into Electricity Could Be More Efficient Than Ethanol

Using biomass to generate electricity could be more efficient than using it to create ethanol according to a new study published today in the journal Science.

A study by University of California, Merced, Assistant Professor Elliott Campbell and two other researchers found that biomass converted into electricity (to power electric vehicles) produced 81% more transportation miles and 108% more emissions offsets compared to ethanol.

In other words, vehicles powered by biomass converted into electricity "got further down the road" compared to ethanol, Campbell said. "We found that converting biomass to electricity rather than ethanol makes the most sense for two policy-relevant issues, transportation and climate."

The scientists based their study on two criteria: miles per area cropland and greenhouse gas offsets per area cropland. In both cases, scientists considered a range of feedstock crops (corn and switchgrass) and vehicle types (small car, midsize car, small SUV and large SUV.

First, they looked at how many miles a range of vehicles powered by ethanol could travel versus a range of electric vehicles fueled by electricity. Second, they examined offsets to greenhouse gas emissions for ethanol and bioelectricity.

Land use is an important factor to consider when evaluating each method. Globally, the amount of land available to grow biomass crops is limited. Using existing croplands for biofuels could cause increases in food prices and clearing new land, or deforestation, can have a negative impact on the environment. (The EPA earlier this week released draft rules concerning this issue.)

The authors are careful to point out their study looked at two criteria, transportation and greenhouse gas offsets, but did not examine the performance of electricity and ethanol for other policy relevant criteria.

"We also need to compare these options for other issues such as water consumption, air pollution and economic costs," Campbell said.

Prior to joining UC Merced, Campbell received national attention for another study that concluded the United States Could meet up to 6 percent of its energy needs with biofuels produced on abandoned or degraded agricultural land.

A copy of Campbell’s abstract can be viewed at the link below.