To study the potential effects of increased biofuel use, we evaluated six representative analyses
of fuel ethanol. Studies that reported negative net energy incorrectly ignored coproducts and used
some obsolete data. All studies indicated that current corn ethanol technologies are much less
petroleum-intensive than gasoline but have greenhouse gas emissions similar to those of gasoline.
However, many important environmental effects of biofuel production are poorly understood.
New metrics that measure specific resource inputs are developed, but further research into
environmental metrics is needed. Nonetheless, it is already clear that large-scale use of ethanol
for fuel will almost certainly require cellulosic technology.

DOE Information