Capacity configuration of cascaded hydro-wind-photovoltaic complementary systems considering comprehensive benefits based on a synergetic-orderly framework

Abstract

The rational configuration of hydro-wind-photovoltaic complementary system is fundamental to fully leveraging the regulation capacity of hydropower and the complementarity between different natural resources. However, complementary systems involving cascaded reservoirs often have comprehensive utilization requirements, which current techno-economic frameworks struggle to address. To solve the above issues, this study proposes a novel framework based on the theory of synergetics to determine the optimal capacities for wind and photovoltaic power considering the comprehensive benefits. Firstly, an inner operation model aimed at maximizing overall order degree is established to optimize the system’s operational performance. Secondly, Kolmogorov entropy is utilized in the outer layer to characterize the synergy of different wind and photovoltaic capacity schemes, thereby selecting the one with the best synergistic effect. Additionally, current techno-economic evaluation indicators are introduced to validate the framework’s effectiveness. A case study of the clean energy base on the upper Yellow River was conducted, and the results indicate that: (1) The proposed framework effectively addresses the comprehensive benefits of multiple subsystems and the optimal capacity scheme performs well in economic and technical aspects. (2) Compared to variations in wind and solar resources, inflow conditions and agricultural water demand have a greater impact on the capacity configuration and operational performance. (3) The optimal capacity ratio of hydro to renewable energy in the upper Yellow River is around 1:0.59. Therefore, this study provides important theoretical support for expanding capacity configuration methods in multi-energy complementary systems.