ANALISIS DEBIT AIR SUNGAI CICATIH DAN KAPASITAS PEMBANGKIT LISTRIK TENAGA AIR (PLTA) UBRUG SUKABUMI

Fluctuations in the Cicatih River water discharge are a major challenge in maintaining the operational performance of the Ubrug Hydroelectric Power Plant (PLTA) in Sukabumi. This study was conducted to analyze the existing water discharge of the Cicatih River, calculate the turbine efficiency of the Ubrug Hydroelectric Power Plant (PLTA), and evaluate the optimal discharge based on seasonal divisions. The study used a quantitative approach with the F.J. Mock hydrological simulation method. The efficiency analysis was carried out by comparing the theoretical and actual power of the hydroelectric power plant during the period 2015–2024. The results showed that the existing annual discharge obtained was in the range of 12.13 m³/s to 17.65 m³/s, the annual turbine efficiency ranged from 83% to 86%, with an average of 85.1%. The optimal discharge to produce maximum power, which is ≥15 m³/s, is only achieved during the rainy season. Conversely, the dry season discharge tends to be 12 m³/s below the optimal threshold, causing a potential decrease in electrical power. While strategic recommendations are given on the development of water storage facilities such as reservoirs or micro reservoirs to accommodate excess discharge during the rainy season with a capacity of around 1.4 million m³, then on the capacity. The turbine is recommended to operate close to the Best Efficiency Point (BEP) by setting the amount of active discharge according to load needs. so that it can be reused when the discharge decreases in the dry season. In conclusion, the efficiency of the Ubrug hydropower turbine is in a stable and optimal condition, but the continuity and maximum power of the generation are greatly influenced by the availability of seasonal water discharge. Therefore, a season-based water management strategy is needed to ensure the sustainability of energy supply and operational efficiency of the plant.
Keywords: Existing Water Discharge, Optimal Water Discharge, Efficiency.