Biofuel Supply Chains: Impacts, Indicators and Sustainability Metrics

Biofuel supply chains in the United States are expected to expand considerably, in part due to the Energy Independence and Security Act (EISA) of 2007. This law mandates through the EPA's Renewable Fuel Standard an expansion to 36 billion gallons of renewable fuels per year by 2022. This paper considers these expanding biofuel supply chains and example impacts, indicators and sustainability metrics for evaluating them. In particular, the impact category considered is reduction of greenhouse gases, the indicator studied is the amount of yield for biofuel crops, and the sustainability metric reviewed is the energy ratio. Ranges of values are found for each of these, and variability and tradeoffs are the expected results in the study of biofuel supply chains.