martedì, 16 giugno 2009; 10:41

Water footprint of biofuels greater 

than other forms of energy

Researchers at the University of Twente in the Netherlands have found that the production of biofuels has a greater water footprint than other forms of energy.

According to the study, the amount of water required to cultivate crops for biomass is significantly greater than the amount of water needed in other forms of energy production.

An example is biodiesel made from rapeseed or soya, which, on average, needs 14,000 liters of water to produce one liter of biodiesel. Jatropha has an even bigger water footprint of 20,000 liters of water for one liter of biodiesel.

The study also found that the generation of bioelectricity via the burning of biomass has a smaller water footprint than the production of biofuels. However, in the generation of bioelectricity, there are also big differences between the crops used. Sugar beet has the smallest water footprint, while Jatropha is 10 times less water-efficient.

Ethanol was also found to be more water-efficient as it can be made from the stalk and leaves of a plant. Sugar beet is once again the most water-efficient, with 1,400 liters of water needed for one liter of ethanol. In contrast, sugar cane needs 2,500 liters of water for one liter of ethanol.

By establishing the water footprint for thirteen crops cultivated for biomass, the researchers presented the impact of the cultivation of the crops on water consumption. The researchers were also able to make recommendations for informed choices of a specific crop and production region based on these water footprints.

By linking the water consumption of a crop to the location and climate data, it is possible to select the optimum production region for each crop and make it easier to prevent biomass cultivation from jeopardizing food production in regions with short water supply. 

-  Katrice R. Jalbuena

http://www.ecoseed.org