Life Cycle Assessment of Biofuel Production/Use in Argentina Incorporating "Water Footprint"

Life Cycle Assessment (LCA) has been used as a tool for assessing sustainability of biofuel feedstocks. Essentially, LCA tracks certain parameters as the bioenergy crop goes through the stages of cultivation, processing and eventual use (combustion) of the biofuel. The analysis usually focuses on the aspects of (1) net greenhouse gas (GHG) emissions and (2) net energy yield. If the net GHG emission is high and the net energy yield (the energy output from the burning of the biofuel minus the energy input to produce the biofuel) is low, the particular biofuel feedstock might have "sustainability issues". The net GHG emission and net energy yield are related to what are known as the ‘carbon footprint" and the "energy footprint", respectively.

There have been calls to also consider the net water consumption (something like a "water footprint") in the LCA of biofuel feedstocks. This is due to the fact that water is a scarce resource in many countries, and it is possible that while net GHG emissions and net energy yields are good for, a particular biofuel feedstock, it may require large amounts of water for bioenergy crop cultivation. Thus, in water-scarce countries, large water consumption may "cancel out" the benefits of a particular biofuel feedstock. Researchers from the Technology and Society Lab (Dübendorf, Switzerland), Institute of Environmental Engineering (Zurich, Switzerland), and the Universidad Tecnologica Nacional (Buenos Aires, Argentina) report the incorporation of water consumption in its comparative life cycle assessment of biodiesel production from irrigated and non-irrigated rapeseed in Argentina.

Among the highlights of their study are: (1) there are no large variations in water consumption in biofuel production chains based on non-irrigated crops, and the water consumption range is said to be at the same level as fossil fuels, (2) "agricultural water consumption dominates the overall results of all irrigated crops", (3) aggregated "Eco-Indicator 99 scores" for biodiesel production from irrigated rapeseed were doubled by water consumption". The full paper is published in the International Journal of Life Cycle Assessment (URL above)

Related information on LCA: http://www.lcafood.dk/LCA/LCA.htm.