The installation works on the Horns Rev C transformer platform, the heart of the Horns Rev 3 offshore wind farm, have finished.
The components of the platform, 1,888 tonne topside and the 1,300 tonne jacket, have been lifted off the transport barges and put in place by the heavy-lifting vessel Stanislav Yudin.
The works were delayed due to harsh weather conditions in the North Sea, so the topside had to wait several days before it was placed on the foundation by the crane. The jacket foundation was secured to the seabed on 11 April.
In the North Sea, the weather could be favourable for one hour, and the next hour, this could be superseded by waves and wind gusts. Therefore, the crew on the vessel were checking out the weather conditions on a regular basis.
“We receive four different weather forecasts for the coordinates where we are in the North Sea. If they each show something different, then there is only only one last option. And that is to look out the window and analyze the buoy we have in the water,” said Thomas Thinggaard , the head of the Horns Rev C sub-project at Energinet.dk.
This requires a buffer of 12 hours to make sure that the weather does not change during the time that it takes to attach the topside on top of the foundation, Thinggard said.
“When we raise the topside, that is a point of no return. It should be placed on top of the foundation and cannot be put back on the ship. It is very nerve-racking. We will not start something we cannot finish without any risk,” he said.
With the two main parts now in place, Energinet.dk will start working on the installations and safety measures to prepare the platform to house the people who will work on the wind farm. The next step is to pull the subsea cable that will lead the offshore wind power to the mainland.
The platform will collect electricity from the Horns Rev 3 offshore wind farm and transform it to a higher voltage level, ensuring a low-loss transmission to shore.
The 400MW Horns Rev 3 will be the largest of the three wind farms off the Danish west coast, and is expected to provide power to consumers as of 2019.
Offshore WIND Staff