Comparative Multi-Criteria Evaluation of Offshore Wind Power Sites: A Case Study in the Aegean Sea

Sammanfattning

The transition toward a fully decarbonized energy system in the Eastern Mediterranean Sea region is fundamentally challenged by a unique combination of extreme bathymetry, congested maritime activities, and historical geopolitical frictions. In the scope of this study, it is aimed to investigate the optimal spatial and economic deployment of floating offshore wind energy in the highly complex environment of the Northeast Aegean Sea. The specific problem addressed in this thesis is how to mathematically balance the profit-driven motives of commercial project developers with the strict environmental and socio-political constraints of national permitting authorities and local island communities. To solve this multidimensional problem, a hybrid Geographic Information Systems (GIS) and Multi-Criteria Decision Analysis (MCDA) methodology is utilized. First of all, spatial exclusion mapping was performed to define two equivalent 500 MW deep-water development areas: one located south of Samothraki in Greece and one located northwest of Gökçeada in Turkey. Subsequently, four distinct grid-connection scenarios, including both domestic and highly controversial cross-border export routes, were evaluated. The Analytic Hierarchy Process (AHP) was employed to simulate the criteria weights of four distinct Decision-Maker groups, and the VISUAL PROMETHEE II software was used to calculate the net outranking flows based on technical, financial, environmental, and social criteria. As a result of the evaluations made, the findings demonstrate a profound divergence in stakeholder preferences. For Project Developers, Permitting Authorities, and National Grid Operators, the domestic Turkish scenario (Alternative 2T) mathematically dominates the ranking. This is primarily due to superior wind speeds reaching 9.25 m/s, shallower transitional water depths of 118 meters, and lucrative local-content feed-in tariffs that yield a maximized Net Present Value of 155 M€. On the other hand, Local Communities and Non-Governmental Organizations strictly prioritize the domestic Greek scenario (Alternative 1G) due to its optimal spatial buffering of 31.61 km from coastal tourism areas and strong alignment with domestic energy security. Furthermore, the sensitivity analysis conclusively proves that cross-border interconnection scenarios are currently unviable, suffering severe penalization from extended submarine cable costs and high geopolitical risk premiums. Ultimately, the study reveals that successful project realization depends entirely on aligning technical configurations with localized social acceptance rather than purely maximizing aerodynamic yield.