Posters

Abstract

Offshore wind turbines (OWTs) are getting larger and larger in size. Most potential windfarm sites with shallow water depths have already been taken. A new steel gravity base for offshore and onshore wind turbines has been developed and patent pending. It is aimed to support large wind turbines of future (e.g. +15 MW) at deep seas (e.g. 30-70 m deep). Desktop studies have proved the feasibility of this foundation concept and has even shown that, this concept is more economical and significantly lighter than conventional concrete gravity bases for medium size turbines (+/- 7 MW); therefore, it can be installed with smaller crane vessels. In comparison with jackets, this foundation is less prone to fatigue. Steel has carefully been used for only the load carrying structure of the foundation and the required weight for its overturning stability is provided by sand. The foundation can be fabricated in small parts in series as many parts are repetitive. Its installation does not generate any noise and the foundation is fully recyclable at the end of its service life. This foundation concept can promote biodiversity in the marine ecosystem if ballasted partially with gravel. In this paper, the foundation concept will be disclosed and the results of the feasibility studies including the structural calculations, geotechnical studies, financial evaluations, and transportation and installation studies will be presented.