Water Values and Marginal Costs For Power Generation Planning Under More Restrictive Constraints and A More Detailed Representation of The Hydro Plants

Power generation planning for real large-scale systems is a complex multistage stochastic problem, which requires modeling approximations for the representations of system components and operating constraints in order to be efficiently solved by the stochastic dual dynamic programming (SDDP) approach. This paper presents an analysis of the impacts of a more detailed representation of the hydro plants and the inclusion of more restrictive hydraulic constraints in the recourse functions that are built by the SDDP strategy, as well as in the simulation outputs of this problem. While some results are rather obvious - as the increase in systems costs - others are counterintuitive, such as the decrease in thermal generation levels and water values in some situations. Results are presented for the individualized modeling of the hydro plants in the official models applied for long-term hydrothermal planning in Brazil.