Integration of Small Pumped Storage Hydropower Units in Water Distribution System Operation

Abstract

Pumped-storage hydropower (PSH) is a proven energy storage technology that can provide large capacity support to the bulk power system. PSH is also a promising technology to increase energy storage capabilities of water distribution systems (WDSs), because these systems have most components necessary for supporting PSH, including a water supply, conduit, pumps, and water storage capacity. PSH must be sized to the water infrastructure that the energy storage will be integrated with, but generally these PSH applications are significantly smaller than traditional PSH units. This paper develops an optimization framework for integration of small PSH units in WDS operation to minimize operating costs associated with power and water consumption in WDS. The proposed model takes into account the hydraulic constraints of WDS and provides optimal operating strategies from an economic perspective based on available units in WDS (e.g., the hydropower generator, variable speed water pumps, and utilization of water storage capacity). The proposed model is applied to a 16-node test WDS using two cases that differ in terms of PSH design to demonstrate the merits of the proposed model. The results provide insight into improved operations for the test system. They also provide the basis for improving operations of more complex WDS systems, including enabling evaluation of PSH design and integration.