Biofuels and water

Abstract

Energy and agricultural water use are linked in synergic and conflicting ways (Hellegers et al. 2008). Large amounts of energy are consumed to pump groundwater to irrigate crops. Multipurpose dams combining power generation and irrigation often justify investments that may not have been eco- nomically feasible for one purpose alone. At the same time, conflicts may arise over water allocation between hydropower and irrigation. Higher demand for energy derived from biomass increases water demand and changes water resource allocation. The cultivation of crops and biomass for food, fiber, or energy requires vast amounts of water (Molden et al. 2007a). Though, at present, the contribution of energy crops in overall agricultural water demand is modest, this may rise as rising energy prices, geo- politics, and concerns over the impacts of greenhouse gas emissions drive increased biofuel production. This potentially leads to more intensive competition between food and biofuel for land and water resources, particularly in already water-scarce areas. Thus, with growing food demand and increasing claims on water resources from other sectors, agricultural water manage- ment must improve.