All 72 wind turbines have now been installed in Vattenfall's wind farm Sandbank in the German North Sea. This means that wind turbine construction was completed three months ahead of the originally planned time schedule.
The turbine construction started at the end of July and already now, 65 of the 4-megawatt Siemens turbines are delivering electricity to the grid on Germanys mainland, 110 km away.
Several factors behind the success
Behind the rapid construction lies a number of factors, says Project Director Niels Bjaert.
“It’s foremost the result of very good planning, selection of a good installation set up, contractual negotiations and monitoring, following up, mitigating risks and hard work,” he says. “The latter comes as a result from a motivated, dedicated and focused team and a good cooperation with contractors, certifiers and authorities.”
To speed up the work and enhance safety, a so called walk-to-work vessel was used for the first time in the German North Sea. The vessel has a gangway from the accommodation vessel to the turbines, enabling work 24/7 and in waves up to 2,5 meters.
“The technology deployed on the project as well as the co-operation between all involved parties have gained a lot in terms of maturity” says Martin Zappe, technical Head of the project at Vattenfall. “We will use these experiences for future projects to implement them as cost efficient as possible, also with regards to the new auction system for coming offshore projects in Germany.”
When fully commissioned in a few months, Sandbank will have a combined power of 288 MW. The annual power production will be 1.4 terrawatt hours.
The Sandbank project
The investment cost for the Sandbank is around EUR 1.2 billion. Vattenfall holds a 51 percent stake of the offshore wind farm, while Stadwerke München (SWM) holds a 49 percent stake. Together with the “sister-project” DanTysk (in full operation since early 2015) the wind farms will have a combined generation capacity of 576 MW.