Energy intensity-based metric for optimal design of water distribution systems

Water distribution systems (WDSs) are some of the most energy-intensive urban infrastructures and thus require efficient energy management. As an essential public infrastructure, a WDS plays an integral role in meeting the water needs of its users at service pressure. Hence, the service level should also be considered when reducing the energy consumption of the WDS. Therefore, to evaluate both energy management and service level, this study proposes efficient returned pressure (ERP) as a metric to optimize the WDS in both aspects by comparing the service pressure to the required energy intensity. During its operating cycle, the ERP considers the pressure and required energy intensity of the demand junctions resulting from the connection of various WDS elements. Using ERP as an optimization objective against the cost for three cases of different active network element configurations, it was discovered that ERP successfully identified solutions that could maximize service pressure while maintaining a minimum required energy intensity. Using ERP provided more effective solutions in terms of cost, greenhouse gas emissions, and network pressure uniformity compared to a conventional index such as the modified resilience index. Overall, the ERP proves to be a feasible optimization parameter when pressure and energy usage is of concern.