Ethanol Can Contribute to Energy and Environmental Goals

TLDR

Earlier studies misreported ethanol’s net energy by ignoring coproducts and using obsolete data, and many environmental effects of biofuel production remain poorly understood. The study aimed to assess the potential effects of increased biofuel use by evaluating six representative analyses of fuel ethanol. The authors evaluated those six analyses and developed new metrics that measure specific resource inputs. Results show that corn ethanol is far less petroleum‑intensive than gasoline yet has comparable greenhouse‑gas emissions, and that large‑scale ethanol use will almost certainly require cellulosic technology.

Abstract

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.