Although it is widely understood that energy and water are the world’s two most critical resources, their vital interconnections and vulnerabilities are less often recognized. This farsighted talk offers a new, holistic way of thinking about energy and water—a big picture approach that reveals the interdependence of the two resources, identifies the seriousness of the challenges, and lays out an optimistic approach with an array of solutions to ensure the continuing sustainability of both.

This presentation brings the water-energy nexus to the building scale discussing tradeoffs that are made on projects. For example, focusing on energy efficiency using evaporative cooling or irrigated landscape for shading saves electricity locally, but at a higher water use which, in turn uses energy at a municipal level to treat and pump that water. Conversely, air-cooled equipment eliminates cooling tower water use, but at lower efficiency therefore using more electricity which uses water at the power plant. Similar to the “site” versus “source” discussion for energy use, the water energy nexus brings this consideration to water use.