The environmental relevance of freshwater consumption in global power production

Abstract

Purpose: Freshwater use and consumption is of high environmental concern. While research has primarily focused on agricultural water use, industrial water use has recently become more prominent. Because most industries employ relatively low amounts of water, our study focuses on electricity production, which is involved in almost all economic activities and has a considerable share of the global water consumption. Materials and methods: Water consumption data for different power production technologies was calculated from literature. Due to the global importance of hydropower and the high variability of its specific water consumption, a climate-dependent estimation scheme for water consumption in hydroelectric generation was derived. Applying national power production mixes, we analyzed water consumption and related environmental damage of the average power production for all countries. For the European and North American countries, we further modeled electricity trade to assess the electricity market mix and the power-consumption related environmental damages. Using the Eco-indicator 99 single-score and compatible freshwater consumption damage assessments, the contribution of water consumption to the total environmental impact was quantified. Results and discussion: Water consumption dominates the environmental damage of hydropower, but is generally negligible for fossil thermal, nuclear, and alternative power production. However, as the impact of water consumption has high regional variation, it can be relevant for many power technologies in water-scarce areas. The variability among country production mixes is substantial, both from a water consumption and overall environmental impact perspective. The difference between electricity production and market mixes is negligible for most countries, especially for big countries such as the USA. In Europe, where intensive international electricity trade exists, the difference is more significant. When contrasted with the relatively high uncertainties in water consumption figures particularly for hydropower, the additional error from using production mixes instead of market mixes is rather small. Conclusions: Power production is one of the major global water consumers and involved in life cycles of almost any human activity. Covering the water-consumption-related environmental damage of power generation closes one important gap in life cycle assessment and also improves data availability for the emerging field of water footprints. © 2011 Springer-Verlag.