Optimal energy recovery by means of pump as turbines (PATs) for improved WDS management

“In water networks characterized by a significant variation in ground elevations the necessity of pumping water in some areas is complicated by a conflicting requirement to reduce excess pressures in other areas. This and the increasing cost of electricity has led to the use of Pumpsoperating- As-Turbines (PATs) devices that can reduce pressure (and leakage) whilst harvesting energy. This paper presents a methodology for optimal water distribution system management, driving the optimisation by minimizing the surplus pressure at network nodes, the operational pumping costs and maximizing the income generated through energy recovery. The method is based on a highly-parallelized Evolutionary Algorithm, employing an hydraulic solver to evaluate hydraulic
constraints. Water demands at network nodes are considered as uncertain variables modelled by using a probabilistic approach in order to take into account unknown future demands. The approach is demonstrated on different case studies. Results obtained highlight that the economic benefits of installing PATs for energy recovery in conjunction with a combined pump-scheduling and pressure management regime is especially related to the input network characteristics. Further analysis of the importance of the probabilistic approach and of the influence of the interval time step adopted for the optimization has been evaluated.”

© IWA Publishing 2017

(Citaat: Tricarico, C., Morley, M.S., Gargano, R., et al. – Optimal energy recovery by means of pump as turbines (PATs) for improved WDS management – Water Science and Technology: Water Supply 18(2018)4, p.1365-1374 DOI: 10.2166/ws.2017.202)