The latest energy life cycle analysis of biodiesel shows that the fuel provides 5.54 times more energy than the fossil energy used to make it. This latest analysis uses 2006 data (the latest year for which complete data are available). This number is called the "fossil energy ratio."
The previous energy life cycle analysis, using 2002 data, showed that biodiesel provided 4.56 times the energy used to make it.
As agriculture and biodiesel processing become more energy efficient, it is expected that the fossil energy ratio of biodiesel will continue to improve.
This research was led by Dev Shrestha, associate professor with the Biodiesel Education Program at the University of Idaho.
For more information, please see this article: http://www.uiweb.uidaho.edu/bioenergy/EnergyLCAJune2011.pdf
