Long-term hydro-thermal coordination via hydro and thermal subsystem decomposition

This paper addresses the long-term hydrothermal coordination problem in electric energy systems. That is, the problem of finding the energy production of every power plant (hydro or thermal) in all subperiods of a given planning period. A solution technique based on thermal and hydro subsystem decomposition is provided. Firstly, the production cost in every subperiod is expressed as a function of the hydro production in the corresponding subperiod. Secondly, the hydro energy is allocated among subperiods so that the production cost over all the subperiod is minimized. The uncertainties related to customer load and thermal generation system are taken into account in the thermal subproblem and the uncertainties related to lateral inflows are taken into account in the hydro subproblem. The methodology proposed shows good computational behavior. A case study is presented to highlight the proposed methodology