Flood Control and Energy Production on the Brazilian Hydrothermal System (PAP014750)

Código

PAP014750

Autores

RENATO CARLOS ZAMBON, Mario Thadeu Leme de Barros, Maíra Gimenes, Pedro Ludovico Bozzini, William W-G. Yeh

Tema

Floods in a changing climate

Resumo

The Brazilian hydrothermal system consists of 151 medium and large hydropower plants with reservoirs, including planned expansion over the next four years. About half of these reservoirs have storage capacity to regulate flows in corresponding basins, while the others are run-of-river. Thirty reservoirs provide 95% of storage capacity. There are also hundreds of smaller hydropower plants, as well as thermal and wind power plants. The hydrothermal system is completely linked in order to maximize total hydropower production while accommodating hydrological diversity among different basins. The main objective of the hydropower operation is to satisfy demand while minimizing the cost of production; in other words, maximize water use and minimize the use of fossil fuels. The system is operated not only for hydropower production but also for flood control, navigation, recreation, and water supply for various purposes. Many of the reservoirs also have storage reserved seasonally for flood control. Dams and spillways have been designed for structural safety during extreme events, such as a 10,000-year flood. The spillways, even in run-of-river reservoirs, also are used for flood control of flows with much smaller return periods, resulting in important economic and social benefits. The flood control reservations must be defined carefully in order to balance the multiple, sometimes conflicting uses of water in the reservoirs. Flood control reservations reduce storage capacity to regulate flows and affect the productivity of hydropower plants in a complex system that must be managed through integrated operation. The management also must consider changes in climate and land use, flood forecast and warning systems, as well as new data available from hydrological monitoring, etc. This paper presents a methodology to evaluate the impacts of flood control and minimum flow constraints on the electric energy production.