The scope and understanding of the water–electricity nexus
The water use associated with electricity generation and consumption has been the focus of research for decades. This study provides an overview of the water–electricity nexus from the perspectives of electricity production and consumption. In terms of production, the electricity generation and associated water use for various regions are summarized and compared. The spatial mismatch between water resource and electricity generation is highlighted and analyzed. It is estimated that the water use will be a vital constraint for future electricity generation in some regions. The technological water saving potential is evaluated to address this issue. In terms of consumption, space cooling/heating and water heating are identified as the most significant nexus-related coupled nodes at the household end-use level. Gaps in the theoretical nexus concept and practical policymaking are summarized herein. Existing policies in the US and Europe related to the water–electricity nexus are also reviewed. This study highlights that the generation and cooling technologies greatly influence the water consumption and withdrawal for electricity generation; tremendous spatial disparities of local water resources and electricity generation exist; residential behavior and household appliances have an impact on the household water–electricity nexus; and comprehensive management of the couplings between water and energy is lacking and urgently required.