Climate Mitigation’s Impact On Global and Regional Electric Power Sector Water Use in the 21st Century

Abstract

Over the course of this coming century, global electricity use is expected to grow at least five fold and if stringent greenhouse gas emissions controls are in place the growth could be more than seven fold from current levels. Given that the electric power sector represents the second largest industrial use of water and given growing concerns about the nature and extent of future water scarcity driven by population growth and a changing climate, significant concern has been expressed about the electricity sector's use of water going forward. In this paper, the authors demonstrate that an often overlooked but absolutely critical issue that needs to be taken into account in discussions about the sustainability of the electric sector's water use going forward is the tremendous turn over in electricity capital stock that will occur over the course of this century; i.e., in the scenarios examined here more than 80% of global electricity production in the year 2050 is from facilities that have not yet been built. The authors show that because of the large scale changes in the global electricity system, the water withdrawal intensity of electricity production is likely to drop precipitously with the result being relatively constant water withdrawals over the course of the century even in the face of the large growth in electricity usage. The ability to cost effectively reduce the water intensity of power plants with carbon dioxide capture and storage systems in particular is key to constraining overall global water use.