The development of a new suction-based foundation for offshore wind turbines has the potential to reap massive savings for the renewable energy sector.
Scientists in Denmark have developed a novel system for attaching offshore wind turbines to the seabed which they claim could dramatically reduce installation costs while also permitting the subsequent removal and re-deployment of equipment.
The new anchoring system, developed by Danish engineering firm Universal Foundation, consists essentially of an inverted steel bucket which is attached to the seabed via the strenuous application of suction pressure.
Large pumps extract water and soil from the cavity of the bucket during the installation process, producing a differential pressure which firmly roots the foundation into the matter of the seabed.
The system dispenses with the need for costly pile driven foundations, while the installation process itself is swift and produces a relatively modest amount of environmental disruption.
The bucket foundation can be installed in a broad range of site conditions without the need for prior preparation or diver operations, and the suction procedure itself is reversible, meaning that turbines can be removed from their original locations for re-deployment elsewhere.
The company has already experimented extensively with a variety of sizeable prototypes, including a 10-by-10 metre unit in Frederikshavn, Denmark which proved capable of bearing a three-megawatt Vestas V90 turbine.
The Carbon Trust has now lent its substantial support to the technology, hosting a 6.5 million pound industry trial of the bucket foundation via its Offshore Wind Accelerator (OWA) – a joint research and development collaboration involving some of the biggest wind power companies in the UK.
Universal Foundation will cooperate with several wind energy companies operating in the North Sea, including Statoil, Statkraft, EON and Dong Energy, to install and test the suction bucket foundation at a trio of proposed offshore wind farm sites.
Jan Matthiesen of the Carbon Trust said suction bucket foundation has the potential to save the offshore wind industry as much as one billion pounds in set-up and construction costs over the next decade.
“The ‘suction bucket’ foundation is a really great innovation for the industry as you can install it faster and at lower costs than conventional steel foundations,” said Matthiesen. “That is good for developers and for consumers as it means it brings down the cost of offshore wind energy. This trial is critical as it will determine the extent to which it can be applied for future offshore wind projects.”
The suction bucket is one of four wind turbine foundation designs which made the shortlist of an international competition held by the Carbon Trust which aimed to find innovative methods for reducing the costs of offshore wind power installation.