The 25,000 tonne Asian Hercules III floating crane successfully completed the first-ever installation of a pioneering suction bucket jacket foundation for Vattenfall’s 92.4 megawatt (MW) European Offshore Wind Deployment Centre (EOWDC) in just 15 hours.
And it’s more exciting than it might sound at first.
The European Offshore Wind Deployment Centre might be a seemingly small offshore wind farm, coming in at only 92.4 MW. But the EOWDC is more than just a wind farm off the coast of Scotland, it’s a demonstration facility for next-generation technologies used in the construction of offshore wind farms. The purpose of the EOWDC is to test and demonstrate new technology that can reduce construction costs and increase construction speed.
“The EOWDC is a cornerstone of Vattenfall’s and the industry’s drive for innovative cost reduction in offshore wind,” explained Gunnar Groebler, Vattenfall’s Senior Vice President of Business Area Wind. “To be fossil free within one generation a climate smart offshore wind programme embracing science and technology is really important for Vattenfall. Where appropriate, we are keen to see the EOWDC’s novel approach to foundations – along with all its other innovations – rolled out to the rest of the industry.”
The EOWDC is the first-ever offshore wind farm to be built using suction bucket jacket foundations — a key factor of the project since its announcement. The best way to describe suction bucket jacket foundations, also known as caisson foundations, is the way 4C Offshore did: “Suction caissons are best described as upturned buckets that are lowered into marine sediment, to anchor structures.” The upturned bucket then has the water pumped out of it to lower the inside pressure, creating negative pressure and extreme weight to sink the foundation into the sea floor.
The reason I’m harping on about offshore wind foundations is the potential such advancements in technology development have to decrease the costs and speed involved in constructing offshore wind projects. These new suction bucket foundations reduce foundation costs due to minimal seabed preparation and are more environmentally friendly and quiet. They are faster to install, as well, which reduces construction time to yield further cost and time savings. There’s also benefits on the backend, with suction bucket foundations being much easier to reverse and remove if necessary.
“The first installation of the suction bucket foundations is a major accomplishment for the EOWDC project team, our contractors and the offshore wind industry,” said Adam Ezzamel, EOWDC Project Director for Vattenfall.
“Suction bucket jacket foundations – which can each be installed with a single offshore lift, virtually without noise and within a matter of hours – bring considerable environmental benefits. They are lowered into the water where the upturned buckets are rapidly embedded into the seabed to create a secure foundation for installation of the world’s most powerful wind turbine later this spring.
“By enabling faster and smarter installation, the technology will drive down offshore wind costs considerably, provide a further foundation option at challenging sites, whilst also allowing an easier and complete decommissioning. These foundations are the first visible structures offshore for the EOWDC which we hope will go some way to help establish the North-east as a centre for offshore wind innovation.”