energies Review Concrete Support Structures for Offshore Wind Turbines: Current Status, Challenges, and Future Trends Alexandre Mathern 1,2,* , Christoph von der Haar 3 and Steffen Marx 4 1 Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins Gata 6, SE-41296 Gothenburg, Sweden 2 Research and Innovation, NCC AB, Lilla Bomen 3c, SE-41104 Gothenburg, Sweden 3 grbv Ingenieure im Bauwesen GmbH & Co. KG, Expo Plaza 10, 30539 Hannover, Germany;
[email protected] 4 Institute of Concrete Structures, Technische Universität Dresden, August-Bebel-Straße 30/30A, 01219 Dresden, Germany;
[email protected] * Correspondence:
[email protected] or
[email protected] Abstract: Today’s offshore wind turbine support structures market is largely dominated by steel structures, since steel monopiles account for the vast majority of installations in the last decade and new types of multi-leg steel structures have been developed in recent years. However, as wind turbines become bigger, and potential sites for offshore wind farms are located in ever deeper waters and ever further from the shore, the conditions for the design, transport, and installation of support structures are changing. In light of these facts, this paper identifies and categorizes the challenges and future trends related to the use of concrete for support structures of future offshore wind projects. To do so, recent advances and technologies still under development for both bottom-fixed and floating concrete support structures have been reviewed. It was found that these new developments meet the Citation: Mathern, A.; von der Haar, challenges associated with the use of concrete support structures, as they will allow the production C.; Marx, S.