Pressure Management and Energy Recovery Capabilities Using PATs

Hydro-turbines are widely used in small water energy production plants in order to turn water kinetic energy to electricity. PATs (Pumps working As Turbines) are micro-turbines (small sized compared to the usual ones) working on “reverse mode” compared to the usual pumps. Installation of a PAT aims to produce energy along with managing/keeping the downstream pressure to a desired level. PRVs (Pressure Reducing Valves) are used to decrease pressure aiming to reduce water losses linked to this extra pressure potential available. The current study focuses on the possibility to replace a PRV with a PAT in a real water distribution network checking its ability to reduce pressure to acceptable levels as well as produce significant amount of energy. The water distribution system of Kozani city (in Northern Greece) is used as the case study network. Various operating scenarios regarding the exact location of the PAT were checked in the network's calibrated hydraulic model with interesting results.