Comprehensive benefit evaluations for integrating off-river pumped hydro storage and floating photovoltaic

Integrating pumped hydro storage with wind-solar power is an effective method for large-scale integration of renewable energy. The integration of floating photovoltaics with pumped hydro storage solves the issues of unstable output from photovoltaic generation and limited land resources. However, traditional pumped hydro storage has limitations in terms of siting and structure, resulting in environmental issues and opposition when integrated with floating photovoltaics. To overcome these limitations, a novel integrated generation system that combines off-river pumped hydro storage and floating photovoltaic is proposed. Additionally, an optimized scheduling model is developed for the hybrid energy power system with the objective of minimizing operating costs. Finally, a case study of a large clean energy project in Qinghai, China is conducted to quantitatively evaluate the comprehensive benefits of this integrated system in hybrid renewable energy power generation from economic, technical, and environmental perspectives. The results indicate that the combination of off-river pumped hydro storage and floating photovoltaics provides improved technological, economic, and environ-mental benefits. Specifically, under the premise of meeting the power supply rate and ensuring power trans-mission reliability, the integration of off-river pumped hydro storage and floating photovoltaic generation system surpasses the traditional integration of pumped hydro storage and photovoltaics in multiple aspects. The inte-grated system can increase power transmission by 26%, decrease investment costs by 15.04%, lower operating costs by 31.75%, save land use by 4.78 km2, and evaporation reduction efficiency by 44.6%. The OFPHS + FPV operation scheme can provide a reference for the development of pumped hydro storage and photovoltaic in-dustries in resource-constrained areas and provide technical guidance to improve the flexibility of regional power systems.