Wind power is emerging as one of the most sustainable and low-cost options for energy production. Far-offshore floating wind turbines are attractive in view of exploiting high wind availability sites while minimizing environmental and landscape impact. In the last few years, some offshore floating wind farms were deployed in Northern Europe for technology validation, with very promising results. At present time, however, no offshore wind farm installations have been developed in the Mediterranean Sea. The aim of this work is to comprehensively model an offshore floating wind turbine and examine the behavior resulting from a wide spectrum of sea and wind states typical of the Mediterranean Sea. The flexible and accessible in-house model developed for this purpose is compared with the reference model FAST v8.16 for verifying its reliability. Then, a simulation campaign is carried out to estimate the wind turbine LCOE (Levelized Cost of Energy). Based on this, the best substructure is chosen and the convenience of the investment is evaluated.

The performance of offshore floating wind turbines (OFWTs) is affected by the movement along the 6 Degrees of Freedom (DOFs), which is caused by the combined influence of wind and waves. Particularly, interesting is the pitching motion, which can lead to significant changes in aerodynamic and net generated power. This paper analyzes the influence of pitching motion on the net generated power, considering for the first time in literature the OFWT control systems (blade pitch and generator controller). An in-house model based on the Blade Element Momentum (BEM) theory is used, in which sinusoidal pitch movements characterized by different values of amplitude, frequency and offset are imposed. In this way, it is possible to evaluate the influence of these three parameters on the extracted power at different values of wind speed. Results identify in the pitch amplitude and frequency the most significant variables for variations in OFWT power output, and that the influence of pitch oscillation on the average extracted power considerably varies at different wind conditions.