PLN, the state-owned electricity company in Indonesia, remains committed to increasing the renewable energy mix and achieving Net Zero Emissions by 2060. This commitment is outlined in the 2025-2034 Electricity Supply Business Plan (RUPTL). A concrete step toward increasing this renewable energy mix is the development of solar power plants (PLTS) or hybrid systems, such as the one planned for Badi Island in South Sulawesi.
The design of a hybrid electricity system combining a solar power plant with a diesel power plant (PLTD) is expected to impact the Net Present Cost (NPC) and the Levelized Cost of Energy (LCOE). The goal is to find the optimal scenario for this hybrid system that results in the lowest possible NPC and LCOE. This research utilized HOMER Pro software to simulate a hybrid PLTD-PLTS-battery electricity system, with an analysis focusing on NPC, LCOE, and carbon emissions. The results of the simulation indicate that the optimal scenario is Scenario 2. This scenario involves a hybrid operation of two diesel generators (PLTD 1 and PLTD 2) with a solar power plant and a battery system. This configuration led to a significant NPC decrease from IDR 41.1 billion to IDR 37.6 billion and LCOE decreased by 8% to IDR 5,264.74/kWh. For CO₂ Emissions can reduced from 454,782 kg/year to 334,751 kg/year.
A sensitivity analysis on fuel prices showed that a significant increase in fuel costs would cause the LCOE to rise to IDR 5,993/kWh from the original IDR 5,264.74/kWh, highlighting the financial impact of fuel price volatility on the system.