Integrating water distribution energy flexibility in power systems operation

Water distribution systems (WDSs) are energy intensive infrastructures that rely on water storage plants and variable speed pumps for delivering water to the end consumers. The WDSs represent suitable candidates for enhancing the flexibility of power systems operation through optimizing the operation of flexible components (pumps and tanks). However, WDSs have traditionally been treated as infrastructure uncoupled from power system operators' efforts to minimize the operation cost of supplying the electricity demand. In this paper, we propose a model for integrating the energy flexibility of WDSs in power systems operation. More specifically, we consider the water distribution system operators (W-DSOs) as an energy savvy entity, who forecast the water demand as well as the electricity prices of the next day, and run the proposed day-ahead WDS operation model to optimize the operation of pumps and tanks for minimizing the operation cost of their local WDSs, while respecting the hydraulic operating constraints of the WDSs. The W-DSOs, then, send the optimized energy consumption to the power system operator, who incorporates the energy consumption of WDSs in the day-ahead operation of the power system using the network-constrained unit commitment (UC) model. The proposed model is implemented on a 15-node WDS that is powered by a 6-bus power system and the results are presented to study the impacts of optimizing the WDS energy flexibility on power system operations as well as on the W-DSOs.