Burning sugar cane or corn to make electricity for powering cars may be smarter than refining the crops into biofuels.
That’s because the vehicles may travel farther on “bioelectricity.”
The improvement in mileage is about 80 percent, said Elliot Campbell, a researcher at the University of California at Merced. Turning food into electric-car fuel also releases less carbon dioxide gas compared with burning biofuels made from the same plants, he said.
Toyota Motor Co. and General Motors Corp. are among the carmakers looking for ways to lower consumption of gasoline and diesel. The industry is struggling through the worst slump in sales in decades amid tougher regulations on CO2 emissions.
“It’s not our plan to put all our eggs in one basket,” Toyota spokesman Paul Nolasco said. “There’s no single approach that can be applied to all situations. The solution depends on where you are and how available different kinds of fuel are.”
Alternatives include using electricity or fuel made with plants, such as corn from the U.S. Midwest or sugar cane from Brazil in the form of ethanol. Also there are more complex synthetic fuels from transforming wood chips and farm waste.
Plant-based fuels are gaining popularity among investors partly because they are less polluting than gasoline, though they contain less energy per unit volume. Refining them consumes additional energy, often using fossil fuels.
Brazil is the world’s second-largest producer of ethanol and no longer has any cars and pickups running on pure gasoline. The South American country requires that automotive fuel be 25 percent ethanol. Sugarcane ethanol accounts for almost 17 percent of the total energy consumption by the automotive sector, according to Brazil’s energy ministry.
Last year, rising demand for biofuel driven by government attempts to fight global warming was blamed for surging prices for corn, rice and soybeans. Higher prices prompted South Korea and Japan to consider investing in agriculture abroad to ensure a stable supply of food.
Governments are offering aid to biofuel manufacturers to speed development. Biofuel subsidies in various forms in the EU, Canada and the U.S. totaled about $11 billion in 2006 and are set to climb to $25 billion by 2015, according to a report by the Organization of Economic Cooperation and Development.
Using fuel made from corn in the U.S. reduces emissions by 10 percent to 30 percent compared with burning gasoline to drive the same distance, the OECD study from last July said.
Campbell and colleagues investigated land-use efficiency, or how much transportation can be achieved per acre of cropland that’s being used to produce plants for energy. The study was published today on Science magazine’s Web site.
‘Lot More Transportation’
“What we found is that if you burn this biomass to make electricity to power electric vehicles, you can get a lot more transportation than if you convert it into ethanol,” Campbell said in a podcast on Science’s Web site. Bioelectricity can be more efficient than biofuels largely because electric motors are economical, he added.
Automakers are testing the dynamics. Nissan Motor Co. plans to sell an all-electric car globally by 2012 while GM aims to roll out a car named the Volt by 2010 that will be mostly electric-powered.
Second-generation biofuels, or those using materials like switch grasses and wood chips to create synthetic fuels, require more “technology advances” in order to make them economically competitive, Campbell said.
Several companies including Germany’s Choren Industries GmbH, which has partnerships with Daimler AG and Volkswagen AG, are racing to develop synthetic biofuels to help meet tougher rules on emissions.
The European Union aims to slash CO2 emissions using renewable energy from the wind, sun and fuel plant derivatives. The 27-member bloc plans to cut carbon output for vehicle fleets to 130 grams a kilometer gradually by 2015.
The UN Intergovernmental Panel on Climate Change has said that global emissions cuts of 50 percent to 85 percent are needed by 2050 to stand a chance of containing the average increase in temperature to 2 degrees Celsius (3.6 degrees Fahrenheit).