Comparative economic analysis across business models of mixed pumped storage power plants in cascade hydropower systems: A case study of the Upper Yellow River in China

Pumped storage power plants demonstrate significant potential in enhancing the flexible regulation capabilities of power systems with high penetration of renewable energy sources. Mixed pumped storage power plants (MPSPPs), developed on conventional hydropower stations, have recently gained attention in the hydropower industry, with shorter construction timelines compared to traditional pumped storage stations. This paper constructs an economic analysis model for MPSPPs in cascade hydropower systems and proposes three representative business models for these plants. Taking the Upper Yellow River clean energy base in China as a case study, this research comprehensively assesses the differences in beneficiary structures, revenue allocation mechanisms, and corresponding electricity price schemes when operating MPSPPs in cascade hydropower systems under different business models. The economic feasibility of MPSPPs for each commercial model is also analyzed. Under the current policy expectations in China, the results show that the joint business model emerges as the most effective in maximizing the profitability of MPSPPs, which yields the levelized cost of storage of 0.2139-0.2641 CNY/kWh. Consequently, the energy sector can encourage MPSPPs to participate in the power dispatching process with more flexible operational business models. Combined with policy support for configuring renewable energy generators and energy storage facilities, this can better realize their value in large-scale clean energy bases.