RWE starts offshore construction at OranjeWind, first monopile installed

en.Wedoany.com Reported - On September 1, the first monopile foundation was installed at the OranjeWind offshore wind project in the Dutch North Sea, jointly developed by RWE and TotalEnergies, marking the start of the project's offshore main construction phase. With a total installed capacity of 795 MW, OranjeWind is planned to accommodate 53 wind turbines, and all 53 monopile foundations are expected to be installed by early 2027.

The project is located approximately 53 kilometers off the Dutch coast. The 53 monopile foundations are supplied by Sif and feature a transition-piece-free design, allowing the turbine tower to be connected directly to the monopile via the top flange. Each monopile measures approximately 90 meters in length and about 8 meters in diameter. The first monopile was shipped from Sif's production facility at Maasvlakte, Rotterdam, to the project area.

Foundation transport and offshore installation are carried out by Jan De Nul, using the heavy-lift offshore installation vessel Les Alizés. The vessel is equipped with a 5,000-tonne crane with a maximum lifting height exceeding 160 meters, and employs a dynamic positioning system for pile position control. The monopile is ultimately driven into the seabed using a hydraulic impact hammer. Les Alizés is currently under a long-term charter arrangement with RWE.

Prior to the installation of the first foundation, Jan De Nul's rock installation vessel Simon Stevin had completed the scour protection filter layer on the seabed, designed to stabilize the foundation area and reduce seabed erosion caused by currents and waves. Following the installation of subsequent monopiles, secondary steel structures such as the main access platform, internal steel structures, and boat landing facilities will also be installed. The wind turbines are planned to be installed by Jan De Nul's jack-up installation vessel Voltaire in a later phase.

According to the current construction schedule, the project's inter-array cables are expected to begin laying at the end of 2026, with the 53 wind turbines planned for phased installation in 2027. The entire wind farm is expected to be fully operational by early 2028. Once fully operational, the annual power generation will be sufficient to meet the equivalent electricity demand of approximately one million Dutch households.

TotalEnergies currently holds a 50% interest in OranjeWind. Its previously published development plan shows that the company intends to use a corresponding portion of the wind power output to support an electrolysis-based hydrogen production project with a total capacity of 350 MW, expected to produce approximately 40,000 tonnes of green hydrogen per year.