The blue water footprint of electricity from hydropower

By M. Mekonnen, Arjen Y. Hoekstra. 2011

244 citations recorded by the source corpus.

Hydropower accounts for about 16 % of the world's electricity supply. It has been debated whether hy- droelectric generation is merely an in-stream water user or whether it also consumes water. In this paper we provide scientific support for the argument that hydroelectric genera- tion is in most cases a significant water consumer. The study assesses the blue water footprint of hydroelectricity - the wa- ter evaporated from manmade reservoirs to produce electric energy - for 35 selected sites. The aggregated blue water footprint of the selected hydropower plants is 90 Gm 3 yr 1 , which is equivalent to 10 % of the blue water footprint of global crop production in the year 2000. The total blue wa- ter footprint of hydroelectric generation in the world must be considerably larger if one considers the fact that this study covers only 8 % of the global installed hydroelectric capacity. Hydroelectric generation is thus a significant water consumer. The average water footprint of the selected hy- dropower plants is 68 m 3 GJ 1 . Great differences in water footprint among hydropower plants exist, due to differences in climate in the places where the plants are situated, but more importantly as a result of large differences in the area flooded per unit of installed hydroelectric capacity. We rec- ommend that water footprint assessment is added as a com- ponent in evaluations of newly proposed hydropower plants as well as in the evaluation of existing hydroelectric dams, so that the consequences of the water footprint of hydroelec- tric generation on downstream environmental flows and other water users can be evaluated.

Subfields: Pollution, Sociology and Political Science, Water Science and Technology

View Paper: https://www.semanticscholar.org/paper/a0dc49a46d5ca901063cdab6ccf598a67a5bdc14