Innovative mini-hydro device for the recharge of electric vehicles in urban areas

The aim of the present study is to evaluate the technical and economic feasibility of supplying recharge points for Electric Vehicles converting water pressure in excess into electric energy from a water distribution network. A real water distribution network was analyzed, by designing a power station consisting of three components: a Pump-as-Turbine, an ad hoc generator, and a control system. The last one controls the flow rate trend at the inlet of the Pump-as-Turbine to regulate the rotational speed corresponding to the optimal range of efficiency. Energy produced permits to supply a recharging point for Electric Vehicles on site with the aim to convert water pressure generally dissipated and, consequently, lost into a renewable energy and to reduce power grid congestion. The economic analysis confirms the convenience of the proposed power station, and overall, a comparable cost with pressure reduction valve devices normally adopted to control pressure pattern and leakages of a water distribution network.