Maximizing both the firm power and power generation of hydropower station considering the ecological requirement in fish spawning season

Abstract

The construction and operation of large-scale reservoirs changes the flow regimes downstream, and thus has negative impact on the aquatic organisms. As an important indicator species, fish is sensitive to flow regimes, which provide stimulus for physiological activity, such as spawning and immigration. On the other hand, the grid-connected large-scale hydropower stations often carry out multiple functions, such as power generation, peak shaving, flood control, and navigation, involving multiple subjects including power plant, power grid, etc. In this study, a multi-objective optimization model is proposed considering the power generation requirement of the power plant, the firm power requirement of the power grid, and the ecological requirement of the fish spawning downstream, simultaneously. The flow regimes is firstly identified and characterized, and the reservoir discharge similar to the natural status is preferred. The proposed model is solved by Non-dominated Sorting Genetic Algorithm II (NSGA-II), and applied to a large-scale reservoir in planning on the upper reaches of the Yellow River in China, where the spawning ground of the plateau cold water fishes will be influenced. The results indicate that the proposed methodology can achieve some balance among different objectives from different subjects, and can be generalized to other large-scale reservoirs that has great impact on the flow regimes downstream.