Optimization of BESS Capacity Based on Kubu Solar PV Output Variability to Support Energy Shifting and Reduce Fuel-Fired Power Plant Operations in the Bali Power System

This study is motivated by the high dependency of the Bali power system on oil-based generation, the significant difference in available generation capacity between daytime and nighttime, and the limited utilization of intermittent renewable energy. This research aims to analyze the variability of the Kubu solar power plant output and to determine the optimal capacity of a Battery Energy Storage System (BESS) to enable Energy Shifting, as well as to improve system efficiency and flexibility. The method employs a quantile-based scenario approach to construct probabilistic scenarios, which are integrated into a stochastic optimization model with the objective of maximizing operational cost savings. In addition, this study utilizes Partial Least Squares Structural Equation Modeling (PLS-SEM) to analyze the relationships among key variables within the system. The results indicate that the proposed method is capable of producing a more representative and robust BESS capacity, while effectively reducing the operation of oil-based power plants through the utilization of solar energy during nighttime periods. The novelty of this study lies in the integration of actual solar output data with a scenario-based stochastic optimization approach, complemented by statistical analysis. The findings imply that BESS has strong potential to enhance system flexibility and support a sustainable energy transition in the Bali power system