Dynamic modeling of an offshore floating wind turbine for application in the Mediterranean Sea

Wind power is becoming one of the best options for renewable energy. Far-offshore wind turbines are attractive in view of exploiting high-speed winds and high wind availability while reducing impact on human and animal population. In the last few years, this technology is having a big development especially in North Europe where there is a great wind resource. Taking note of this, there are currently no offshore wind farms installations in Mediterranean. The aim of this thesis is to model an offshore floating wind turbine in its entirety and examine the behavior resulting from a wide spectrum of sea and wind states describing a specific site near Pantelleria, in view of a future installation of a wind farm in this site. By moving far from littorals, fixed foundation configurations are no longer viable and the increasing sea depths rise the costs of moorings, installation and maintenance for floating foundations. About this, in this thesis several options will be analyzed to minimize these costs and obtain optimal performances. In the first place, an overview of the state of wind power, and offshore in particular, is given. The thesis continues by introducing the system specifications that will be the basis on which the model is built. The following chapters, after outlining their respective theoretical background, illustrate the modeling of the wind turbine with its aerodynamics, the moorings and the floater with its hydrodynamics. Then, the model is compared with FAST v8.16, a simulation tool for floating or fixed wind turbine, to verify its reliability. In the final section the reference site is described along with the simulation campaign; using a genetic algorithm, the best properties are extracted in view of an optimal sizing.