16.07.2026

From a distance every offshore wind farm looks the same: rows of turbines rising from the sea, their blades turning quietly in the wind. But step closer - or in this case, talk to Matthias Esken, RWE's Project Director for OranjeWind - and a very different picture emerges. One where geology, engineering, logistics, and human dynamics all contribute to make OranjeWind a project with its own set of characteristics.

OranjeWind is RWE's offshore wind project in the Dutch North Sea, developed in equal partnership with TotalEnergies. With foundation installation expected to begin in late summer 2026, the project is on track. First delivery of power to the grid is planned for spring 2027, and by early 2028 OranjeWind's 53 turbines with a combined capacity of almost 800 MW should become fully operational. All this thanks to both careful planning, learnings from previous projects and the experienced project team's ability to navigate a set of challenges that are anything but routine. (Read more about OranjeWind, its various sub-projects and partner contributions in the latest Technology report)

Engineering in unchartered terrain

The seabed beneath OranjeWind is one of those challenges. Strong underwater currents in the area have sculpted relatively high sand dunes across the project site, a geological feature that the project team had to take into account for the cable installation. "Sometimes we need to dredge away some of the dunes before we can lay or trench the cables," Matthias explains. It's a detail that no one would notice from afar, but one that demands specific solutions during construction.

Entering new turbine territory

The wind turbines themselves, a new generation supplied by Vestas, add a further layer of complexity. Each new turbine model introduces updated physical and electrical interfaces, meaning that connecting them to designs developed for previous generations is not simply a matter of 'plug-and-play'. "With every new turbine generation, you enter new territory, so to say," Matthias notes. "We have had to adapt previous interface designs to this specific turbine. We did so based on learnings from Nordseecluster project which uses this same new turbine type. "

Achieving precision when everything moves

Perhaps the most technically demanding aspect concerns the installation of the monopile foundations. OranjeWind's monopile (MP) installation vessel is the Les Alizés, operated by Jan De Nul. This large and relatively new ship is designed for floating mode installation rather than the jack-up mode more commonly used in the past. The distinction matters quite a lot in practice. A jack-up vessel extends legs to the seabed and thus creates a stable, fixed platform. With installation in floating mode, a vessel moves with the sea.

"You can imagine: if you want to install a pile in floating mode and you have waves or swell, you don't just have movement around the pile, you have movement of the vessel itself," Matthias says. "Even small movements of half a metre or so need to be compensated by the gripper system that holds the pile in place." Managing the interaction between the pile, the waves, the currents, and the motion of the vessel requires precision engineering and careful operational planning. With the experience RWE and Jan de Nul gained in previous projects that also used the Les Alizés, Matthias is confident the project team will be able to manage this in OranjeWind too.

Knowing what lies beneath

Compounding this is the variation in soil resistance encountered from one turbine location to the next. At some spots, a pile will penetrate the seabed under its own weight even after first penetration depth by its self-weight before a single hammer blow is struck, this is known as pile run. At others, the resistance is far greater. Getting this wrong may have consequences for the hammer, for the vessel, as well as for the people working on it. To prevent this, the project team conducted seismic and sonar scans of the seabed, building detailed soil profiles for every turbine location across the wind farm. To be able to cope with the pile runs, various mitigation measures have been identified and implemented to allow a safe installation. "We need to be clear, per location, what can be expected, and how we react on that," Matthias says.

Securing scarce resources

Through all of this the infrastructure needed to support the offshore wind industry - suitable ports, specialist vessels, installation equipment - remains a bottleneck. Throughout the project, the OranjeWind team has had to manage access to these scarce resources carefully. Fortunately, with companies such as Sif, Vestas, TKF, Jan De Nul, Smulders and DEME, OranjeWind has been successful in finding partners that are able to support the safe and timely delivery of the project.

Doing a dry run in Hoboken

An onshore dry run took place just prior to the actual installation, at the site of sub-contractor Smulders in Hoboken, near Antwerp. "We installed part of a foundation there and together with our key installation contractors, we performed all kinds of physical, handling and procedural checks. We have tested installation tools and cable pull-ins, we did rescue drills and emergency response actions. Basically, we did everything to prevent surprises that might occur during installation at sea. And while you will always find bits and pieces that can be further optimised, we have not run into anything significant so far."

Tapping the deep expertise within RWE

In addition to these promising trial results, what gives Matthias and his team the confidence to tackle challenges of this complexity? In part, it comes from the breadth of expertise that RWE and its partner TotalEnergies are able to bring forward. "If there is an issue," he says, "there's a good chance that you find somebody in our organisation who has knowledge about that and knows how to tackle a particular problem. Everybody loves what they do and is excited about offshore wind. You always find good help in our team, and I am convinced that will be decisive in making OranjeWind a success in the end."