Challenge

The global expansion of offshore wind turbines places significant demands on the entire value chain, which currently employs around 32,000 people in Denmark, from the delivery of raw steel to the fabrication of structures and wind turbines, and ultimately, the installation of offshore wind farms. To support the upcoming expansion, a wide range of Danish technological expertise needs to be leveraged to further accelerate industrialization. It is essential to increase fabrication capacity.

Future offshore wind farms will use turbines with capacities exceeding 15 MW. These large turbines, along with the installation of turbines in deeper waters – and even on floating support structures – will result in significantly higher fatigue effects on the load-bearing structures. This, using current technology, will require a substantial increase in the necessary material thicknesses for the load-bearing welded steel structures, such as wind turbine towers, monopile foundations, and pipe structures used in floating support structures, in order to prevent catastrophic failures due to metal fatigue. The increased material thicknesses will, in addition to an increased material consumption and thus weight, also require more robust production, transport, and installation equipment, which will put additional pressure on the value chain.

Solution

The overarching goal of the project is to identify and implement welding-improving measures so that automatic processes can achieve a fatigue strength that is not significantly lower than the base material. The project will be based on existing technologies with proven effectiveness but developed and tested on a smaller scale at technology centers and universities.

Fatigue properties are improved by optimizing the geometry of the welding and by reducing welding stresses through the use of vibration technology, VDW (Vibration During Welding). The improvements should be able to be implemented in welding processes that are already used industrially. The aim is to ensure that the implementation of the improvements does not reduce productivity; the measures should be able to be integrated into or run parallel with the already used processes.

The project is co-financed by the Ministry of Education and Research.

Impact

Through the project, the partners aim to demonstrate that by combining the tested technologies, there is potential to reduce steel consumption by up to 40% in critical components for one of the most important energy sources for the continued global green transition. If the project succeeds in demonstrating the possibility of reducing the material thickness of metal structures and thereby achieving a corresponding material saving, it will result in both a green and economic benefit, as materials and transportation of turbine components are the typical costs associated with wind turbine production.