IN Brief:
- Nordlicht I’s first transition piece has been installed in the German North Sea.
- DEME is using Orion and Sea Installer for foundations and transition pieces.
- The 68-turbine, 980MW wind farm is scheduled to enter operation in 2028.
Vattenfall has installed the first transition piece at the 980MW Nordlicht I offshore wind farm, advancing the German North Sea project into the next stage of foundation construction.
DEME’s jack-up vessel Sea Installer completed the operation while working alongside the heavy-lift vessel Orion. The two vessels are carrying out the monopile and transition piece installation programme.
The milestone follows installation of the first Nordlicht I monopile in July. Transition pieces had already begun arriving from manufacturing and load-out operations, but placing the first unit offshore establishes the structural interface needed before tower installation can begin.
A transition piece links the foundation below the waterline with the turbine tower. It provides the corrected level and alignment required for erection and normally incorporates access platforms, ladders, boat landings, cable interfaces, corrosion protection equipment, and working areas used during construction and operation.
The component’s position between monopile and tower creates demanding installation tolerances. The structure must be level, correctly oriented, and ready to accept later tower, cable, and access packages. Surveying and connection work must be completed offshore before the position can progress.
Nordlicht I is being built around 85 kilometres north of the German island of Borkum. The project will use 68 Vestas offshore turbines and is scheduled to reach completion and grid connection in 2028.
At 980MW, the wind farm concentrates substantial generation across 68 positions. Each turbine contributes roughly 15MW of rated capacity, increasing the mechanical and electrical consequence of every foundation, array cable connection, turbine transformer, and protection interface.
Vattenfall took the final investment decision on the Nordlicht projects in 2025. Nordlicht I has since entered physical construction, with the first monopile installed in early July and the transition piece programme now under way.
The installation is distinct from the earlier delivery of Nordlicht I transition pieces. Manufacturing, port load-out, transportation, and offshore installation are separate stages, each carrying different equipment, inspection, weather, and scheduling constraints.
Sea Installer must lift each transition piece from its transport arrangement, position it over the installed monopile, and complete the structural connection. The vessel’s jacking system provides a stable platform above the waves, although operations remain dependent on acceptable wind, wave, and current conditions.
Orion’s monopile work establishes the foundation positions that Sea Installer follows. The sequence must avoid vessel conflicts while preventing completed monopiles from waiting unnecessarily for transition pieces. Survey vessels, support craft, transport movements, and offshore teams add further activity around the construction area.
The installation campaign forms one part of a broader programme covering turbines, inter-array cables, offshore electrical equipment, export infrastructure, and grid connection. Foundations create the physical platform, but generation cannot begin until the electrical chain from each machine to the onshore network has been completed and tested.
Inter-array cables will collect output from the turbine strings and deliver it to the offshore system. Protection devices, communications, supervisory control, reactive power equipment, and metering must operate as one coordinated installation once staged energisation begins.
The scale of Nordlicht I places pressure on the supply chain beyond turbines and foundations. Cable production, high-voltage equipment, installation vessels, commissioning specialists, port capacity, spare components, and trained offshore personnel are all required within a defined sequence.
Transition pieces remain operational assets after construction. Their access systems will be used throughout the wind farm’s life, while coating condition, corrosion protection, structural integrity, seals, electrical interfaces, and platform equipment will require inspection and maintenance.
Installation of the first transition piece shows that the offshore sequence is becoming established. Repetition will now matter more than the individual milestone because all 68 turbine positions must progress through foundation, transition piece, cabling, turbine installation, and commissioning.
Offshore programmes rarely advance at a uniform daily rate. Weather interruptions, vessel maintenance, component availability, inspection findings, seabed conditions, and interface work can alter output, forcing contractors to resequence activity without creating prolonged gaps between manufacturing, transport, and installation.
Installation records for each position will feed the final handover package, including survey data, connection details, inspection results, and evidence that the completed structure matches the approved design. Those records will later support operation, maintenance, and any investigation of abnormal loading or corrosion.
Nordlicht I remains scheduled for operation in 2028. Vattenfall and its contractors must complete the foundation programme, install turbines and electrical systems, connect the array to the transmission network, and carry out staged testing. The first transition piece closes one interface; another 67 turbine positions must still follow the same construction chain.
