Abstract: This paper describes a new model based on the microeconomic principle of diminishing marginal productivity during the production process to economically and reasonably exploit the regulatory capacity of hydropower station reservoirs and to facilitate the efficient integration of wind and solar resources. This model considers the regulating capability of the reservoirs as a variable factor, treating the efficient consumption of wind and solar resources as a "fixed factor". It aims at maximizing the benefits of hydro-wind-solar co-generation and can be solved to obtain optimized operation plans for the reservoirs to facilitate the economic consumption of wind and solar resources. Case analysis demonstrates that under the given condition of inflow, load demand, reservoir operation status, and other factors, the model effectively reflects the reservoir’s contribution to the economic consumption and the co-generation benefits during its participation in wind and solar output regulation. Optimized operation scheme is given for the reservoirs involved in wind and solar output regulation under different scenarios. The model helps leverage fully the regulating capacity of the reservoirs and enhance the co-generation benefits while ensuring the safety of power systems.

Key words: regulatory capacity of reservoirs, economic consumption of wind and solar resources, law of diminishing marginal productivity, generation efficiency maximization model, hydropower station reservoir