Researchers eye better use for biomass than ethanol

By Jasmin Melvin

WASHINGTON, May 7 (Reuters) - Using switchgrass and other biomass to power electric cars is three times more efficient and more environmentally friendly than using ethanol to power traditional gasoline cars, U.S. scientists have found.

Electric vehicles using biomass converted into electricity traveled 81 percent farther per acre of cropland than vehicles with internal combustion engines running on cellulosic ethanol, researchers in California found.

A small sport utility vehicle could do 9,000 highway miles (14,484 km) on the energy produced from an acre of switchgrass converted into ethanol. But converting that biomass into electricity allowed a battery-powered SUV to get 14,000 miles (22,531 km) on the highway, the study published in Science magazine said.

"One of the driving factors that lead to this result is that the electric motor is much more efficient than the internal combustion engine," said the lead author of the study Elliott Campbell, an assistant professor at the University of California, Merced.

"For the small SUV class of vehicles, the electric motor was 3.1 times the efficiency of the internal combustion engine vehicle," he said.

Bioelectricity can be produced at existing coal-fired power plants by blending up to 15 percent biomass with coal, similar to the process where ethanol is blended with gasoline.

Both ethanol and bioelectricity help reduce carbon dioxide from being released into the atmosphere.

But both require some greenhouse gas emissions to make and process the plants used as biomass.