This study aims to show a c GIS-based site-selection with multi-criteria decision analysis for offshore wind farms while taking into account energy and exergy efficiency analyses of the selected model wind turbine. The analytic hierarchy process (AHP) was used to identify potential sites dependent on several critical physical parameters. The first phase of the study is the data collection, which involves the construction of a geographic information system (GIS). The second phase is the exclusion step. In the final stage, energy and exergy efficiencies of the wind energy generating system have been investigated. Meteorological parameters are examined on exergy and energy efficiency, and results are shown. The most significant result achieved from this study is that Bozcada has potential sites for installing offshore wind turbines by means of meteorological parameters and suitable location.