Most engineers focus on improving energy efficiency to reduce energy consumption. There is, however, another important component that impacts energy use and that has, to this point, been largely ignored — water consumption. Water and energy are invariably intertwined into what is referred to as the energy water nexus.

Water is needed for drinking and irrigation but also for production of energy and cooling. As global clean water levels fall, demand for cooling and energy consumption rises. In states such as Texas, California, Arizona, and the rest of the Southwest, water scarcity is a hotly debated and prominent topic. On a worldwide scale, water usage is outgrowing the population¹. To make a significant impact on the energy-water nexus, water consumption must be considered from two perspectives: the building and the power source.