Life cycle assessment of biofuels in the European Renewable Energy Directive: a combination of approaches?

Abstract

The European Renewable Energy Directive (RED) was produced by the European Parliament and the Council of the European Union to promote the uptake of energy from renewable resources by participating member states. It sets greenhouse gas (GHG) saving targets for renewable transport fuels and dictates the method by which this should be calculated. This study examines the life cycle assessment (LCA) methodology set out in the RED and compares it to attributional and consequential assessments. A case study of wheat-based bioethanol is used to illustrate how differences in methodology affect the GHG emission results. The results show that GHG emissions from wheat bioethanol are lowest when calculated under the RED, and highest when substitution credits are applied. The RED has been shown to not only combine attributional LCA and consequential LCA approaches but also to contain rules for specific co-products. For example, cereal residues are not allocated GHG emissions from cultivation, and exported electricity is awarded a credit based on similar electricity generation from the same source. It is suggested that these rules may be a reaction to concerns over indirect global land use change, and therefore these methodological anomalies in the RED place artificial biases in GHG emission results.