Industry experts have known for many years that water and energy resources and infrastructure are inter-related. However, it wasn't until the California Energy Commission issued its landmark findings in 2005—water-related energy use accounts for nearly 20% of all electricity and 30% of non-power plant natural gas consumed in the state—that this interrelationship, aka "the water-energy nexus", became an important area of focus.
The sheer magnitude of this number captured the attention of a broad spectrum of stakeholders—from water and energy policymakers, utilities and large customers, to environmental advocacy groups and research organizations—who rushed to explore ways to quickly reduce water-related energy consumption.
Currently, the California Public Utilities Commission (CPUC) is considering pilot programs to help determine the amount of embedded energy* that could be achieved by saving water. In addition, since fossil fuel-based electric production is a major emitter of greenhouse gases, the potential to reduce water-related energy consumption became an important part of California's strategy to implement AB32. Further, the Energy Commission's Public Interest Energy Research (PIER) division has commenced development of its first Five Year Water-Energy Strategic RD&D Plan and Roadmap.
As both policymakers and market players attempted to qualify and rank opportunities, it became apparent that existing data and tools were not able to support integrated analyses of water, energy and carbon costs and benefits.
* "Embedded energy" is the amount of energy that is deemed "embodied" in a unit of water through energy consumed in collecting, extracting, conveying, treating, and distributing the water to end users (upstream embedded energy) and then by treating and disposing of the wastewater (downstream embedded energy).