were explored such as assisting power supply by using maritime energy source such as solar power, wind power or tidal power or operating ultra low power systems. In this study, the energy harvesting system and power management algorithm for complex energy production system using solar power, wind power and tidal power used for operating floating buoys were designed and developed. By using this system, the electricity management system of each power source that has been previously managed individually is managed as an integrated system with capability of more efficient power management and supply, hence extending the operation hours of floating buoys while providing stable power supply.