Review of approaches for modelling sea and lake ice loads on offshore wind turbines

Offshore wind turbines must be built to withstand harsh marine conditions, including significant wind and wave loads. To be economical, the structures are designed to be relatively light, and as a result, the loads can result in significant non-linear effects, coupling between responses of the turbine and supporting structure, and susceptibility to fatigue. In regions such as the Baltic Sea, the Bohai Sea, the Great Lakes, and offshore Eastern Canada, sea or lake ice is present in winter. Ice in higher concentrations suppresses waves but results in direct ice loads on the structure. Global and local ice loads need to be assessed in such cases. This paper reviews design requirements and models for global ice loads for offshore wind turbines. Focus is given to the structure types and ice conditions that might be encountered off Eastern Canada or in the Great Lakes.