Windmill installation in the North Sea

On assignment for Norwind, NGI has contributed to the installation of offshore windmills from a platform in the German sector in the North Sea. NGI has verified the installations of piles for the foundations of the windmills.

Alpha Ventus is the first real offshore windfarm project in Germany, located 4 hrs from the shore West of Borkum reef. The reasons for being so far out are both wind conditions and the marine park closer to shore.

NGI is contracted by Norwind to measure the exact pile top positions after piling 30m below the sea surface. These measurements are very important as the jacket structure for the wind turbine will be directly inserted onto the piles. They must fit with quite tight tolerances.

NGI also ended up monitoring and controlling the final pile driving, making sure that the piles are in level with each other. This is a paramount operational criteria as the levels of the piles determine the verticality of the wind tower. One pile cannot be driven deeper than the others. The piles have been installed within centimeter precision, which is pretty good.

Six ares have been installed with four foundation piles each, two metres diameter and 30-40 m into the sebed.