An Operative Framework for the Optimal Selection of Centrifugal Pumps As Turbines (PATs) in Water Distribution Networks (WDNs)

The current significant increase in energy consumption has resulted in the need to develop and implement effective approaches for defining alternative and sustainable solutions to couple primary resources with supporting methods of energy generation. In the field of effective water distribution network (WDN) management, the suitability of combining pressure regulation with small-scale hydropower generation is attracting even more interest, given that it can possibly reduce water leakages, as well as produce attractive rates of renewable energy. Specifically, pumps as turbines (PATs) are widely considered a viable solution because they combine hydraulic benefits with affordable investment and management costs. Nevertheless, despite several approaches available in the literature for the optimal selection and management of PATs, choosing the most suitable device to be installed in the network is still a challenge, especially when electrical regulation is arranged to modulate the PAT rotational speed and optimize the produced energy. Several approaches in the literature provide interesting solutions for assessing the effectiveness of electrical regulation when a PAT is installed within a water network. However, most of them require specific knowledge of the PAT mechanical features or huge computational efforts and do not support swift PAT selection. To overcome this lack of tools, in this work, an operative framework for the preliminary assessment of the main features (the head drop and the produced power at the best efficiency point (BEP), the impeller diameter and the rotational speed) of a PAT is proposed, aimed at both maximizing the daily produced energy and performing challenging economic selection. Then, it is assessed by estimations of the corresponding payback period (PP) and the net present value (NPV)