Coherence between water and energy policies

The global nexus between energy and water introduces crosssectoral vulnerabilities whereby water problems can become energy problems and vice versa. This creates cross-cutting opportunities where solutions for one sector might also be good for the other. However, the tradeoffs between prospective technical and policy solutions are not obvious. To address that challenge, this article presents a novel framework for analyzing coherence in technologies and policies at the energy-water nexus. Challenges are laid out, examples of mixes of technology and policies that can meet political objectives relevant to the energy-water nexus are given, gaps that inhibit future policy development are identified, and key findings are discussed. The analysis is presented through data specific to the United States along with a few case studies from other countries for illustration, but the framework is relevant to policymakers and decision makers globally. The article covers technical and environmental issues linking water and energy in electricity generation, liquid fuels production, and freshwater and wastewater treatment. It also explores the tradeoffs between specific technologies and policies relevant to the energy-water nexus. Some policies and technologies present solutions that achieve water and energy security, while others do not. Institutional reforms that could help water and energy policy to be more coherent, robust, and sustainable in the future are identified, and case studies from different countries are included to broaden the discussion. Finally, the article concludes by discussing emerging issues and information gaps in the energy-water nexus.