Brazilian Hydrothermal Dispatch Optimization: Replacement of Inflow Tree by Lattice

The Brazilian hydrothermal dispatch optimization has characteristics of a dynamic and stochastic problem. The stochasticity is represented by inflows tree, which increases exponentially with the raise of the number of stages analyzed, making harder the long-term planning. In this context, this article proposes the replacement of the representation of uncertainty scenarios from tree to lattice in order to reduce the computational effort to solve this problem. Lattices increase linearly and they are used when the scenarios are path independent. As a way to test the viability of this replacement it is presented a case study based in Tocantins basin data using tree and lattice. Comparing the results of the two methods it is possible to conclude that they are very close, so it is perchance possible to replace the inflow tree by lattice for longer periods when it would not be possible to apply the conventional method.