Preliminary assessment of a pump used as turbine in a water distribution network for the recovery of throttling energy

Nowadays, the increasing energy demand represents a priority issue to be faced on social, economic, political and technical points of view. For a sustainable development, renewable energy sources should be preferred to the conventional ones. In water distribution networks, Pumps as Turbines (PaTs) can represent a cost-effective alternative to conventional turbines for the recovery of the throttling energy. In this framework, a preliminary assessment of the installation of a PaT in the water distribution network of Casamassima, a town in the Apulia region (Southern Italy), has been conducted. A PaT, suitable for this application, has been tested in both direct and reverse modes at the test rig of the Department of Mechanics, Mathematics and Management of the Polytechnic University of Bari. Then, starting from the analysis of the pressure and flow rate patterns during the day and the night, three installation cases have been evaluated and compared in terms of hydraulic energy harvesting and power output useful to supply an electrical charging station.