This study deals with system integration and controller design for power management of a stand-alone renewable energy (RE) hybrid system, which is in its construction stage in Lambton College (Sarnia, Ontario, Canada). The system consists of five main components: photovoltaic (PV) arrays, wind turbine, electrolyzer, hydrogen storage tanks, and fuel cell. The model for each process component is developed and all the hybrid energy system components are integrated in a MATLAB/Simulink environment. A hierarchical control system is implemented, comprising of a supervisory controller, which ensures the power balance between intermittent renewable energy generation, energy storage and dynamic load demand, and local controllers for the PV, wind, electrolyzer and fuel cell units. A decentralized model predictive control (MPC) was designed and implemented on the electrolyzer and fuel cell to ensure optimal power flow.