BorWin5 Onshore – De Romein GmbH is Working on the Energy Transition

Progress of the BorWin5 project

Major project BorWin5 for the safe and low-loss transport of green offshore electricity is progressing – De Romein GmbH is creating the onshore route from Hilgenriedersiel to the Garrel/Ost converter station with the egeplast Power Protect protective pipe system. To connect the EnBW He Dreiht offshore wind farm, spanning 230 km between the BorWin epsilon offshore platform and the Garrel/Ost converter station, TenneT has initiated the BorWin5 grid connection project. De Romein GmbH is undertaking the civil engineering and cable installation work along the onshore route and is relying on egeplast Power Protect PE protective pipe systems for the 55 km section that requires piping.

The BorWin5 project of TenneT Offshore GmbH comprises the construction and operation of a grid connection from the BorWin epsilon offshore platform to the Garrel/Ost converter station in the Cloppenburg district. The 320-kV-DC line Bor- Win epsilon – Garrel/Ost (BorWin5) with a total length of around 230 km is complex in terms of its design and consists of an offshore and an onshore passage. Starting from the BorWin epsilon offshore platform, the line initially runs offshore within the Exclusive Economic Zone (EEZ) to the border of the 12-nautical mile zone. From there, it runs offshore to the island of Norderney, then over or under the island, then through the Wadden Sea to the landing point near Hilgenriedersiel and on along the onshore route to the Garrel/Ost converter station. The high-voltage cable system for BorWin5 consists of three cables (two conductor cables and one control cable), which are laid together in a cable trench.

Complexity of the construction project

NKT HV Cables AB (AG) has been awarded the overall contract for the turnkey installation of the BorWin5 high-voltage cable system and has already completed the civil engineering and cable laying work from the BorWin epsilon offshore platform to the Hilgenriedersiel landing point in recent years. De Romein GmbH (AN), as a subcontractor of NKT HV Cables AB, has been commissioned to carry out the civil engineering and cable laying work on the land route from Hilgenriedersiel to the Garrel/Ost converter station.

Ronny Buit, De Romein Construction Manager for the BorWin5 HDD project, uses concrete figures to illustrate the scale and complexity of the construction project: “Approximately half of the approximately 110 km long route will be piped, which means a requirement of approximately 110 km of pipes. This means that several truckloads of egeplast Power Protect PE 100 225 x 20.5 mm protective pipes must be delivered directly to the cable route weekly to meet the constant demand for welded pipe strings for the six HDD systems. The total of 45,000 excavator mats, which are continuously laid, picked up, and transported, also illustrates the dimension of the project. The same applies to the 112 cable drums to be transported, with a total weight of 4,500 t, each weighing 40 t and wound with two km of underground cable. All cables must first be landed at the Cable Hub in the Port of Emden, from where they are transported by low-loader to the various unwinding sites directly along the route, where they are installed or pulled in during the final step.”