The Technical & Economic Feasibility of Energy Recovery in Water Supply Networks

Abstract

Water supply is a core service on which civilised society  depends.  It  involves  considerable  energy  consumption and,  as  a  result,  CO2  emissions  (in  water  treatment,  pumping and  monitoring)  and  economic  costs.  Treated  water  is  most commonly  supplied  from  a  central  storage  reservoir  by  gravity throughout a catchment and this water  must be supplied within satisfactory  pressure  bands.  Where  the  pressure  in  water  flow becomes  too  high,  a  Break  Pressure  Tank  (BPT)  is  commonly installed  in  the  network,  whereby  the  pressure,  kinetic  and potential energy within the flow is dissipated to the atmosphere. These  BPTs  present  an  opportunity  to  recover  energy  from water  supply  networks  by  means  of  a  hydropower  turbine system,  thereby  improving  the  sustainability  of  the  network without  interfering  with  the  water  supply  service.  This  paper presents  the  results  of  a  preliminary  technical  and  economic feasibility assessment of the energy recoverable from BPTs.