(491e) Comparison of Methodologies Between Greet Life Cycle Analysis and Life-Cycle Analysis-Based Fuels Regulations

The GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model has been developed at Argonne National Laboratory with the support of the U.S. Department of Energy. It is a life-cycle analysis (LCA) model to examine energy and emission effects of various vehicle/fuel systems by including fuel production stages and vehicle operations. With more than 20,000 registered users, it helps organizations determine energy and emission effects of advanced vehicle technologies and new transportation fuels. In recent years, the model and its results have been used in the U.S. for fuel regulations such as the California’s low carbon fuel standards and U.S. EPA’s renewable fuel standards. On the other hand, the European Commission has developed a tool called BioGrace to help its own Renewable Energy Directive. In conducting LCAs, GREET and these regulations deal with several key methodological issues in great details. Such issues include ways of dealing with co-products in fuels LCAs, system boundary definitions (with inclusion of indirect effects), and data variability and analysis uncertainties. In this presentation, we will present the similarities and differences regarding these issues among these efforts and examine their impacts on LCA results.