Deriving Operating Rules of Pumped Water Storage Using Multiobjective Optimization: Case Study of the Han to Wei Interbasin Water Transfer Project, China

Abstract

Pumped water storage (PWS) is an advanced component of interbasin water transfer (IBWT) projects that plays a critical role in addressing streamflow variability. However, improper operating rules result in a large amount of unnecessary pumping and spills, wasting water resources and energy. Here, multiobjective optimization (MO) was applied to develop effective operating rules for PWS with the objectives of minimizing the water shortage index and maximizing the net revenues of consumed and produced energy. A metaheuristic algorithm named cuckoo search was used to optimize the decision variables in the framework of parameterization–simulation–optimization. Additionally, the water diversion performance of PWS and parallel reservoirs (without pumped storage) were compared. The Han to Wei IBWT project in northwest China was selected for a case study. The results indicate that (1) the proposed MO model and adopted methods are effective for derivation of PWS operating rules, improving water use benefits and decreasing operational costs significantly; (2) the two optimization goals established in the MO model conflict (increasing water supply reliability will decrease the net revenue of energy); and (3) when the water diversion target is relatively small, parallel reservoirs outperform PWS; however, PWS is superior to parallel reservoirs when the water diversion target increases.