Electrical energy has a fundamental role in life. Burung Island, an island in Indragiri Hilir Regency, Riau Province, has an electricity system supplied by the 3,5 MW diesel power plant with a daily operation time of 14 hours. Riau is the largest palm oil producer in Indonesia. POME (Palm Oil Mill Effluent) and EFB (Empty Fruit Bunch) can fuel biomass power plants. This research aims to compare the use of POME and EFB as fuel for a biomass power plant that will be operated hybrid with the existing diesel power plant. HOMER (Hybrid Optimization Model for Energy Renewables) Software simulates the hybrid power plant. From the study, it can be concluded that the POME and EFB-based hybrid system can meet the 24-hour electricity needs of Burung Island and is feasible to implement. The POME-based hybrid power plant has a better performance than the EFB-based. The POME-based power plants can reduce the workload of diesel power plants by 26.2%, while the EFB-based power plants can reduce by 23.6%. The LCOE of POME-based power plants is Rp6.615,34, while the LCOE of EFB-based power plants is Rp6.714,68.