Measuring the hydroelectric regularization capacity of the Brazilian hydrothermal system

The storage capacity (or “regularization capacity”) of a hydro system refers essentially to its capability of transferring excess inflow energy from wet to dry seasons. The Brazilian hydro power system is formed by hundreds of reservoirs capable of multi-year storage capacity. Historically, this has been measured in the Brazilian Power System in terms of the duration of the critical period, which in turn is obtained from optimization models that calculate the firm energy (FE) of hydroelectric systems. These models, however, only represent the hydroelectric system explicitly and do not take into account the synergy between hydro and thermal plants. This synergy can be an important aspect in defining the storage capacity of the hydrothermal system. The objective of this article is: (i) to define a methodology for measuring the regularization capacity of a generation system; (ii) to analyze by this measure the current regularization capacity of the Brazilian system; and (iii) to analyze the impact of the development of large-scale run-of-the-river hydro plants that are in the pipeline to start commissioning in the next years.