The University of Dundee is to lead a major research project to determine whether cheaper, more environmentally friendly, and more effective foundations can be developed for the offshore renewables industry.
The project, funded by a £1 million grant from the Engineering and Physical Sciences Research Council, will look at the use of screw piles for offshore installations. These are foundations which are screwed into the ground and are widely used onshore.
“The UK has challenging targets for expansion of energy from renewables with the potential for over 5000 offshore wind turbines by 2020,” said Dr Mike Brown, Senior Lecturer in Civil Engineering at the University of Dundee, who is leading the project.
“The necessary move to deeper water will increase cost and put greater demands on subsea structures and foundations. There is already cost pressure on the offshore sector as people wait to see if it can be made more affordable, so we really need to find better solutions for how we develop capacity.
“Screw piles are potentially very attractive as a lower cost and more environmentally friendly option. However, there are significant challenges to be addressed. If we are to develop them for offshore use they will likely be larger than those used onshore, and face different pressures, so our work will look at whether they can meet the performance and efficiency issues.”
Currently, the main foundation solutions being considered for offshore wind installations are driven piles, large monopiles or concrete gravity-based structures (GBS). Driving of piles in large numbers offshore causes concerns over plant availability and impact on marine mammals.
There are also concerns over the limit of practical monopile development and the high material demands of GBS. Screw piles have the potential to overcome these issues and are scalable for future development from current onshore systems which have relatively low noise installation and are efficient in terms of both tensile and compressive capacity, University of Dundee wrote.
The research has the potential to make it easier to deploy screw pile foundations for offshore renewables. This project will develop foundations able to deal with current water depths and will provide understanding of the behaviour of piles as water depths and the demands on the foundations increase.
“By harnessing the installation and performance benefits of screw pile/anchor technology, the results of the project will hopefully contribute to an overall cost reduction in electricity generated by renewable means and increase the public’s confidence in the future viability of this energy source,” said Dr Brown.
The project is being led by the University of Dundee and includes contributions with the Universities of Durham and Southampton and also private sector partners Cathie Associates Ltd, Screwfast Foundations Ltd, SeaRoc Group and Soil Machine Dynamics UK.