This special issue explores case studies on the challenges and opportunities facing a variety of countries using energy to meet water demand.  Articles address policy relevant topics like the relationship between energy availability and growth, treatment of polluted water, and carbon emissions. The objectives of the special issue are threefold.  First, it explores the similarities and differences in countries with regards to managing energy for water.  Conclusions show that, while countries may face unique water challenges such as severe scarcity, polluted groundwater, or underdeveloped water transport networks, these problems are united in the fact that any solution involves significant energy use. Second, the issue offers detailed analysis on how different technologies are used to extract, treat, and transport water in countries.  Special attention is paid to water used for irrigation, given that it represents a majority of water withdrawn in countries.  The case studies demonstrate successes and failures by countries, and offer ideas for best practices among nations.  Last, the issue examines the controllable and uncontrollable factors affecting the potential for countries to make improvements in energy use for water. By exploring these three components – policy developments, technology use, and controllable vs uncontrollable factors – the special issue offers a robust exploration into the “energy for water” side of the water-energy nexus equation.