Pumps as turbines for energy recovery in water distribution systems: a review

Abstract

Energy recovery and pressure management are essential to achieve sustainable improvements in the development of water distribution systems (WDS). An alternative that has been studied worldwide is the use of pumps as turbines (PAT) replacing pressure reducing valves (PRV) to conciliate pressure control and energy production. This work aims to investigate the current and most recent literature regarding the use of PAT, addressing technical and economic implications that the technical-scientific community has analyzed. The search terms used in the Scopus and Web of Science databases were {‘pump as turbine’ AND ‘water supply network’, ‘water distribution network’ OR ‘water distribution system’}. A total of 59 papers were analyzed, highlighting the operation of PAT as well as selection and location methods, with the evaluation of electricity production, decreased leaks, and especially a suitable cost/benefit ratio. The review indicates that PAT have been infrequently used in real systems. However, the application is greatly feasible from the technical and economic points of view, and in a scenario of variable-speed PAT, the amount of energy produced is high. Future research should be directed to the optimization of new PAT settings so they can better deal with the operational variations in the systems.