Improved technology combined with solid experience enables MT Højgaard to supply and install foundations for offshore wind farms with greater efficiency. It will help make energy from offshore wind farms more profitable in the future.
On 4 September, Denmark's largest offshore wind farm near the island of Anholt will be officially inaugurated. It is just over a year since MT Højgaard completed the installation of the 111 wind turbine foundations.
Offshore wind farms are gradually being installed in deeper waters which means that the cost of the foundations will represent an increasingly large proportion of the total installation cost. MT Højgaard is working with other players in the industry to find solutions that can optimise the process and reduce the cost.
"Anholt has been a complex and challenging project, during which we have honed our skills in reducing installation time and thus cost, for example by optimising the supply chain and by making small adjustments to the installation methods," says Kim Andersen, Offshore Director at MT Højgaard.
It took just 18 months from the commencement of the contract until the foundations were installed, so speed was a distinct feature of the Anholt project.
"The entire installation was fast and efficient. We mobilised the installation vessel and installed the first monopile ahead of schedule, and maintained a higher installation rate than planned, which enabled us to keep to the tight timetable," says Kim Andersen.
Anholt Offshore Wind Farm is the 12th offshore wind farm for which MT Højgaard has installed the foundations. The company is among the world's most experienced in this area. It is the kind of experience which could prove important to the future of sustainable energy supplies.
"There is huge potential in offshore wind farms, but it must also be worth establishing them from the financial perspective. We have now developed the technology so that both the design and installation phase of the foundations have become more efficient. This will help keep down the installation costs, also when the offshore wind farms are installed in deeper waters," says Kim Andersen.
MT Højgaard supplied and installed 111 monopile foundations. On top of the monopiles, transition pieces were installed to carry the Siemens 3.6 MW wind turbines. The monopiles have an average diameter of 5 metres, a length of 50 metres and a weight up to 460 tons.
Anholt Offshore Wind Farm is operated by DONG Energy. By the end of 2013 it is forecast that the offshore wind farm will supply electricity to 400,000 households, corresponding to approximately 4% of Denmark's annual consumption.