Life cycle assessment of algae-to-energy systems

Abstract

Algae-derived bioenergy is being widely discussed as a promising alternative to bioenergy produced from terrestrial crops. Several life cycle assessment (LCA) studies have been published recently in an effort to anticipate the environmental impacts of large-scale algae-to-energy systems. LCA is a useful tool for understanding the environmental implications of technology, but it is very sensitive to modeling assumptions and techniques. In this chapter, the methodological issues surrounding LCA of algae-to-energy systems are reviewed in the context of several of the recent papers with a particular focus on system boundaries, cultivation techniques, metrics, coproduct allocation, and uncertainty. The issues raised here are useful in two regards: (1) they enable an understanding of the differences between the published studies and allow LCA practitioners and others to more directly interpret the results and (2) they serve as a good starting point for future analysis of algae-to-energy technologies.