The Brazilian interconnected power system consists of a linked network of over 150 medium and large reservoirs, and a large set of small hydropower, thermal, and wind power plants. In Brazil, hydropower has been the predominant source of electrical energy supply, but the system has changed significantly over the last five years. From 2003 to 2012, 91% of the electrical energy was supplied by hydropower plants, while the reservoir system operated with, on average, 68% of active storage. From 2013 to 2017, 74% was supplied by hydropower plants, while the reservoir system operated with, on average, only 39% of active storage. Wind power provided, on average, of less than 1% until 2013, and increased to 8% in the last four years. Energy demand, hydropower production, reservoir storage, wind power generation, and thermal dispatch have shown significant changes within their shared patterns and seasonality. Additionally, a series of recent moderate to severe droughts occurred in Brazil. An important question that needs to be addressed is: Is it reasonable to operate for more than five years with such low levels of reservoir storage? Furthermore, with the added issues of water security and system resilience, what is the effect in terms of productivity reduction in this complex system of reservoirs? In this paper we use the HIDROTERM, a nonlinear programming optimization model previously developed for planning the operation of the Brazilian hydrothermal system, to estimate the hydropower productivity reduction within recent years with low reservoir storage variations.
Artigo retirado do site: https://ascelibrary.org/doi/abs/10.1061/9780784482339.011