Pump-As-Turbine: Characterization as an Energy Recovery Device for the Water Distribution Network

Abstract

The distribution of water is an energy intensive process in which potential to recover energy currently wasted exists, via the installation of microhydro energy recovery systems. Pump-as-turbine (PAT) technology offers an economically viable solution; however, the lack of performance data for PAT technology is a major barrier to its widespread use. As a context, the water distribution network (WDN) also adds technical complications to the use of PATs: Pressure needs to be regulated to allow effective distribution of water to consumers and flow conditions are based on user demand and thus, are variable. This paper outlines the result of experimental investigations of this concept at laboratory scale, quantifying its potential as an energy recovery device for use within the WDN. Hydraulic arrangements where flow is fixed through the PAT and variable through the bypass yielded maximum potential energy recovery. Up to 39% of the available energy was shown to be recoverable using this arrangement.