Energy Management - Towards Energy Neutral Wastewater Treatment

摘要

Energy consumption is typically the second or third largest item in a wastewater utility’soperations and maintenance budget and has been trending steeply upwards in both quantity andunit cost. The recent economic recession has placed additional financial burdens on wastewaterutilities as they strive to meet increasingly stringent discharge requirements with aginginfrastructure in need of repair and replacement. Energy conservation, on-site generation, andrenewable energy are becoming increasingly important to wastewater utilities as energy policy,energy economics, and actions to mitigate climate change converge with the need to meet higherstandards of wastewater treatment.Energy is a cost item that utilities can control through practical approaches and proventechnologies. Many utilities are beginning to reduce grid-connected energy consumption at theirfacilities through a variety of energy demand and on-site energy production measures.Technology advancements combined with operational best practices are bringing into focus thereal possibility of achieving energy neutral wastewater treatment. The Water EnvironmentResearch Foundation (WERF) is implementing research programs to develop and deploy newpractices, technology, and information to help wastewater treatment facilities achieve thischallenging but realistic goal of net energy neutrality.Applying fundamental concepts of energy conversions and net energy balance at wastewatertreatment plants, this paper describes the methodology by which the typical net energy gap wasdetermined for wastewater treatment plants in the U.S. The paper addresses the energyefficiency best practices, technologies, and future research required for wastewater treatmentplants to close the gap and achieve energy neutrality.