Yield Model for Screening Multipurpose Reservoir Systems

A screening model for selecting and sizing potential reservoirs and hydroplants on a river basin is presented. The system is designed to meet annual irrigation and hydropower demands at prescribed levels of reliability. The model is developed with a focus on considerations that are important to the Indian decision makers. A linked simulation-optimization framework is used for formulation. Sizing of reservoirs and hydroplants, and evaluation of objective function and constraints and their derivatives are done as part of simulation. For sizing reservoirs, a new sequent trough algorithm is used that considers evaporation losses automatically. Generator capacities are determined by maximizing the local net revenues produced from hydropower generation. Derivatives are evaluated using automatic differentiation that produces exact derivatives with minimal human effort. The resulting formulation is applied to Par, Auranga, Ambica, and Purna river basins located in India. Comparison of model solutions with those of the state agency shows that the present formulation leads to a reduction in the system storage and cost of its development.