Environmental life cycle comparison of algae to other bioenergy feedstocks.

The recent publication of, "Environmental Life Cycle Comparison of Algae to Other Bioenergy Feedstocks" in the journal of Environmental Science & Technology by Clarens et al. (2010), has generated significant attention within the bioenergy field. The authors of the study report that algae has greater greenhouse gas emissions, higher nutrient requirements, and greater water use relative to corn, switchgrass, and canola bioenergy feedstocks. The analysis presented by Clarens et al. (2010) contains numerous assumptions that significantly affect the published result that algae is inferior to current terrestrial bioenergy feedstocks from a Life Cycle Analysis (LCA) perspective. The most serious critique of the Clarens et al. (2010) analysis is that the negative lifecycle analysis for algal fuel is directly determined by the choice of input values and assumptions.