The limited energy supply in remote areas such as Enggano Island, Bengkulu, remains a serious challenge in achieving equitable and sustainable national energy development. The region’s electricity system still relies entirely on Diesel Power Plants (PLTD), which are known for their high fuel consumption, operational costs, and significant carbon emissions. This study investigates the potential for developing a hybrid power generation system combining PLTD and Solar Power Plants (PLTS) as a solution to support the clean energy transition. The analysis was conducted using HOMER Pro software to simulate various system configurations based on the existing PLTD technical data, local solar radiation potential from the NASA database, and projected load demands over the next 25 years. Several hybrid system scenarios were designed by integrating 1.5 MWp of PLTS, battery storage, an inverter, and PLTD as a backup. The simulation results indicate that this integration can reduce fuel consumption by more than 30% annually, lower CO₂ emissions by approximately 1,500 tons per year, and produce a Levelized Cost of Energy (LCOE) of IDR 3,200/kWh, which is lower than a standalone PLTD system. The simulation also shows that the renewable energy penetration exceeds 33%, while system efficiency and power supply reliability are maintained throughout the year. The study concludes that the PLTS–PLTD hybrid system is not only technically and economically feasible, but also represents a strategic step in supporting energy sector decarbonization in underdeveloped regions.