What are the potential benefits of biofuels versus conventional fuels such as petroleum?
• Energy efficiency: Estimates of the energy balance of corn-based ethanol vary, but recent studies using updated data on corn production methods demonstrate a positive energy balance for corn ethanol. Cellulosic-based ethanol provides an even greater benefit in terms of energy efficiency. • Greenhouse gas emissions: The carbon dioxide released when ethanol is burned is balanced by the carbon dioxide captured when the crops are grown to make ethanol. This differs from petroleum, which is made from plants that grew millions of years ago. According to the Argonne National Laboratory, on a life-cycle analysis basis, using corn-based ethanol instead of gasoline reduces greenhouse gas emissions (GHGs) by 19% to 52%, depending on the source of energy used during ethanol production. The GHG emission benefit of biofuels, however, can be compromised if land use changes offset the direct GHG emission reductions. Cellulosic ethanol could reduce GHG emissions even further. • Socio-economic benefit
