Presentations

Abstract

Our consortium is developing two floating offshore wind farm in Italy, each having an expected capacity around 1GW, one located 22km off the north-west coast of Sardinia in water depth ranging from 200m to 1100m, and another one located 22km off the south-west coast of Sicily in water depth ranging from 280m to 650m. As part of the development process, a geophysical survey has been conducted at each offshore wind farm area. The purpose of such survey is to characterize seabed morphology, shallow geology, potential geohazard, detect anthropogenic or natural features and better understand biodiversity, habitats and other factors. These data will be an important input to assess the potential environmental impact and will be used during the subsequent engineering phases. Due to the depths and slopes at the wind farm areas, it appeared challenging to achieve an acceptable data resolution with conventional towed system. The surveys were thus performed using an Autonomous Underwater Vehicle (AUV) which is able to acquire data at a constant height above the seafloor, allowing full coverage at high resolution. Once subsea, the AUV is not affected by weather or vessel movement. The AUV is launched from a surface vessel with a defined line pattern. Once the line pattern is completed, the AUV returns to the surface and is recovered onboard the survey vessel to then be launched again with the next line pattern. The AUV performed 24 hours missions and acquired high-quality data which allow us to better understand these areas.