Next generation of wind turbine foundations

Work underway in HR Wallingford’s Fast Flow Facility, a marine test facility, will support the design of a novel suction bucket foundation, which will ultimately lead to more cost-effective seabed foundation solutions for the renewable energy industry, the company said.
Part of the research project is to determine how structures interact with, and impact upon, the hydrodynamic conditions and the seabed.
As offshore wind farms move into ever deeper water, developers are exploring alternatives to the traditional monopile foundation to reduce costs and keep the technology competitive within the energy marketplace, HR Wallingford noted.
The action of waves and currents can lead to erosion of the seabed around wind turbine foundations. This phenomenon, known as scour, poses a risk to the stability of the foundation and, in extreme cases, has the potential to cause structural failure. Although scour is relatively well understood for traditional monopile foundations, it is not yet the case for complex foundation types.
“The forces acting on offshore wind foundations will typically increase as water depth increases. For complex foundations, we currently use a combination of approaches to estimate likely scour, and this introduces a level of uncertainty in the design process. This research with DONG Energy will help us to develop greater certainty in the prediction of seabed response and design more efficient foundation solutions. Ultimately this will help to make offshore wind developments more costs effective, and developments in exposed locations and deeper waters more economically viable,” said Richard Whitehouse, HR Wallingford’s technical director.
Designs that have been shown to be reliable in the laboratory are likely to be adopted by developers as there is also a requirement for the technology to be proven before its application for use in large-scale developments, HR Wallingford said.  
Andreas Roulund, lead oceanographic engineer at DONG Energy Wind Power added: “The ability to have novel designs tested by physical modelling is crucial for development of our foundations. We can observe how the seabed responds to the foundation in the extreme conditions found in the North Sea. We have found the new Fast Flow Facility at HR Wallingford tailor made for this purpose.”