Energy and exergy analyses of a hybrid hydrogen energy system: A case study for Bozcaada

In the study, a hybrid energy system for hydrogen and electric production is conceptually developed and applied to an island, Bozcaada. A thermodynamic analysis is performed using energy and exergy approaches. The conceptual system is examined from the viewpoints of economic and energy load distributions by the Hybrid Optimization Model for Electric Renewable (HOMER) tool. In the study, stand-alone island model is selected for analysis scenarios. The model consists of photo voltaic (PV) array, wind turbines, electrolyzer, polymer electrolyte membrane fuel cell (PEMFC), hydrogen tank and converter. Energy and exergy analyses are applied to determine of the locations and magnitudes of system inefficiencies. The analyses are essentially made for the main equipment under dynamically changing operating and environmental conditions. In addition, hourly distributions of changing energy and exergy rates are illustrated. As a result, the daily average energy and exergy efficiencies of the PV array are 13.31% and 14.26%. Also, the efficiency values are calculated for the wind turbine as 46% for energy and 50.12% for exergy and the electrolyzer equipment as 59.68% for energy and 60.26% for exergy, respectively.