Monopile foundations for offshore wind turbines - solutions for greater water depths

A study into the feasibility of monopile foundations at sites in the North Sea with water depths as great as 35 m has been carried out in which various options for the geometric configuration and the selection of material were considered. In parameter studies, simplified design methods were applied to assess the effects of the individual load components at the draft design stage. The fatigue limit state becomes more and more relevant as the water depth increases; therefore, dynamic effects must be examined with special care. Turbine concepts with low RNA mass and low rated speed help to achieve the desired design in the soft-stiff regime. As a result, it can be said that monopile foundations with their great manufacturing advantages can be constructed for water depths beyond the current limits of practical experience if the logistical challenges in handling large masses are solved.