Multi-Objective Optimizations of Hydroelectric Exploitation Using Dynamic Programs in Citarum Cascade Reservoirs

Abstract

Saguling, Cirata, and Jatiluhur are reservoirs built on the Citarum River, in West Java, Indonesia, which have the main function as power plants. It is deemed necessary for Jatiluhur Reservoir to have the right operating pattern to get optimal water management since it is different from other reservoirs. Citarum cascade which has a multi-reservoir operations pattern has a problem because of deviations that occurred on the realization of the trajectory against the planned trajectory guidelines. This happens due to the complex relationship between physical variables and hydrological uncertainty. To overcome this problem the dynamic programming of the Bellman model was used through optimization with forecasts of future discharge. Bellman model is the best approach for non-linear conditions because it can integrate stochastic properties. In addition, to overcome the curse of dimensionality in multi-reservoir operations, the Du Couloir iterative method is applied. In optimizing the management of the Citarum cascade reservoirs, a variety of water usage prices per month was used as the economic variable. The results of this research are as follow: a utility function to achieve the goal of maximizing hydroelectric benefits is achieved, the needs of raw water downstream are refilled, and no water will be wasted through spillways. The application of this method to reservoir optimization can overcome dimensional issues with exponentially faster computation times.