Impacts of the Upstream Storage Reservoirs on Itaipu Hydropower Plant Operation

This paper presents some results related to the operation of the Itaipu hydropower plant. Itaipu is one of the largest hydropower plants in the world. It is a binational undertaking run by Brazil and Paraguay at the Paraná River on the border section between the two countries. Each country owns 50% of the installed capacity (14,000 MW). This study evaluates the impacts of the upstream storage reservoirs on the hydropower production of Itaipu. The analysis involves a system of 55 hydropower plants. Itaipu hydropower plant operates as a run-of-river reservoir and itself does not have storage capacity. However, there are many upstream storage reservoirs located in Brazil. The analysis is conducted using the HIDROTERM decision support system (DSS), which is basically an optimization model. HIDROTERM is designed for the management and operation of large hydrothermal systems. In its formulation the hydro plants are considered individually and the thermal plants are aggregated into subsystems. The optimization model is capable of handling different types of constraints, such as water transfers, multiple purposes and environmental requirements. Its objective function is to produce energy at a minimum cost. HIDROTERM integrates a database with basic information (hydrological and technical) to run the model and an interface to manage input and output data. The optimization model is written using the General Algebraic Modeling System (GAMS) package and so it can run with different nonlinear programming (NLP) routines. The results from the analysis show that the upstream reservoirs located in Brazil have significant impacts on the hydropower production of Itaipu.