Energy Intensity of Water: Literature Suggests Increasing Interest Despite Limited and Inconsistent Data

Water agencies use energy to pump, treat, and distribute potable water. Wastewater treatment plants use energy to collect, treat, and discharge wastewater. The energy intensity of water—the energy embedded in a unit of water delivered—varies considerably depending on the water source, the location and size of the agency’s service area, and the treatment technology employed. The frequency at which agencies collect energy use data also varies, as does the degree to which those data are available. Available estimates of the energy intensity of water also vary greatly. There is a growing recognition within the water and energy communities that new water supplies will likely be increasingly energy intensive and that water conservation efforts will thus result in energy savings. As a result, there is increasing interest in understanding baseline energy use, projected energy use, and opportunities for reducing energy consumption by water and wastewater agencies. The collection of additional, more consistent and more granular data is essential to gaining this understanding.”