The new BAM Report has been published, presenting selected research projects on future safety-related topics. One of the featured projects examines how offshore wind monopiles can use less steel while achieving a longer service life. Offshore wind farms require large quantities of steel for their foundations. Most offshore wind turbines are installed on monopiles, large steel tubes that can exceed 100 metres in length and reach up to 12 metres in diameter. A single monopile can require more than 2,000 tonnes of steel. Corrosion and continuous mechanical loading currently limit their operational life to around 30 years.
The BAM-coordinated OptiMP project is investigating how monopiles can be designed, manufactured and operated more efficiently. The project covers the full process chain, including design, production, transport, installation and long-term operation, with the aim of reducing material use and extending service life.
According to Marc Thiele from BAM’s Wind Competence Center, the project expects to achieve steel savings of up to 10% and extend monopile service life by up to 30% through targeted improvements across the process chain.
Part of the research focuses on weld seams, which are critical for the long-term structural integrity of monopiles. Researchers are examining whether welds can be designed or treated to improve fatigue resistance, potentially allowing thinner steel plates to be used.
The project is also studying how installation methods affect monopile durability. During installation, monopiles are driven into the seabed using hydraulic hammers delivering thousands of impacts. Researchers believe the resulting fatigue damage may be lower than previously assumed, which could support more material-efficient designs.
The project also aims to support updates to standards used for offshore wind monopiles, many of which are based on general steel construction standards originally developed for bridges and buildings.
Participating organisations include the Fraunhofer Institute for Large Structures in Production Engineering, Leibniz University Hannover, JBO Engineering Group, Grillo Zinc Metals and Vattenfall Europe Windkraft. Associated partners include EEW Special Pipe Constructions, Siemens Gamesa, EnBW, Skyborn Renewables and DNV Renewables Certification.
The project is funded by the German Federal Ministry for Economic Affairs and Energy under the 8th Energy Research Program.
BAM, the Bundesanstalt für Materialforschung und -prüfung, is a research institute of the German Federal Ministry for Economic Affairs and Climate Action.
