The system is designed to connect the He Dreiht wind farm, located in the North Sea off the coast of Cloppenburg in Germany, to the onshore grid.
Construction of the HVDC platform has been carried out in Puerto Real, Spain, by Dragados Offshore, from where it has already departed for the North Sea by barge.
Sarens' involvement in this project stands out as one of the most significant in the company’s history, involving one of the largest deployments of axle lines to date and the heaviest module ever lifted worldwide.
The new BorWin5 high-voltage direct current (HVDC) transmission system will be of vital importance for the smooth operation of the He Dreiht wind farm, which is currently under construction off the German coast of Cloppenburg in the North Sea. Thanks to this unit, it will be possible to transport the energy produced at the installation- estimated at 900 MW - to the onshore grid and supply more than one million households in Germany with clean energy.
This unit, which has been assembled in Puerto Real, in the province of Cadiz (Spain), by Dragados Offshore, is already travelling to the North Sea by barge. Once in its final location, it will be installed together with the 64 Vestas V236-15.0 MW turbines that the He Dreht wind farm will have, before its expected commissioning at the end of 2025. He Dreiht, one of the first offshore wind farms to be built without public funding, is seen as one of the cornerstones of Germany's energy transition.
Sarens, world leader in heavy lifting, engineered transport and crane rental services, was strategically involved in the tasks of transporting the jacket and topside from the manufacturing plant where the HVDC unit was assembled to the barge (1,5 km approx.) on which it travels to the North Sea. To do this, the Sarens technical team decided to use around 2000T of transport stools, 48 load cells and 500T jacks, as well as 476 axle lines of SPMTs. This project stands out as one of the most significant in Sarens’ history, involving one of the largest deployments of axle lines to date and the heaviest module ever lifted worldwide.
The Sarens team, operating on behalf of Dragados Offshore, encountered a challenging scenario due to three weeks of heavy rains off the coast of Cadiz, which made the assembly of the transport stools particularly difficult. Similarly, the task of removal of 2000T of stools from beneath the topside was also a major challenge, as the structure had numerous protruding parts that required a specially careful maneuvering.
HVDC units are of paramount importance for the correct operation of any offshore wind farm, as they are responsible for transforming the alternating current generated by the turbines into direct current. In the case of the BorWin5 unit, it will be responsible for the energy conversion and transport of the electricity generated via a 120 km underwater cable to Norderney, and then via a 110 km underground cable to the onshore connection point.
According to José Mª Martínez, Sarens Key Account Manager, “with the transport of the BorWin5 HVDC unit, we have proven our ability to adapt to any type of task thanks to the use of the most advanced high-tech equipment, but especially thanks to the experience we have acquired over decades in projects of all types and magnitudes. Although this time we have set a record for our company, we are ready to break this record and continue to tackle strategic projects that contribute to the energy transition in Europe or anywhere else in the world”.
Sarens has extensive international experience in the assembly and maintenance of wind farms. It has participated in various installations in France such as Fécamp, Saint Nazaire, Provence Grand Large and in the lifting and transport work for the foundation bases of the new offshore wind farm in Saint Brieuc, located off the Brittany coast. During this project, Sarens successfully transported loads weighing over 1150 tons. More recently, Sarens has been actively involved in the reception and loading operations of monopiles and transition pieces for 176 turbines for the Coastal Virginia Offshore wind farm in the US and the marshalling and installation of 62 monopiles in the Moray West offshore wind farm, each weighing up to 2000 tons, the largest and heaviest XXL monopiles ever to be handled in the UK.
About Sarens
Sarens is the global leader and reference in crane rental, heavy lift and engineered transportation services. With state-of-the-art equipment, value engineering, one of the world's largest inventories of cranes, transporters and special rigging equipment, Sarens offers creative and intelligent solutions to today's heavy lifting and engineering transport challenges.
With more than 100 entities in 65 countries operating without borders, Sarens is an ideal partner for small to large-scale projects. Sarens currently employs 5,000 highly qualified professionals who are ready to serve the needs of any client worldwide and in all market sectors. https://www.sarens.com/