Let's talk

SEANEX | PFISTERER Connectors selected for 66KV Wind Turbine terminations at Seagreen project

Posted on 14 March 2022

SEANEX | PFISTERER Connectors selected for 66KV Wind Turbine terminations at Seagreen project


66kV Wind Turbine Terminations At Seagreen Project

SSE Renewables and Vestas have selected the offshore-optimised SEANEX inner cone system by PFISTERER to connect more than 100 wind turbines in the Seagreen project in the Western North Sea.

PFISTERER is supplying SEANEX joints as well as preassembled and tested cables with SEANEX connectors for construction. Each of the Vestas turbines will be connected using SEANEX accessories. The cable joints and preassembled cables link the submarine cables to the gas-insulated switchgear (GIS) in the tower of the turbines.

“We are pleased that our SEANEX solution has been selected for this project. This confirms that in SEANEX, we have developed a compact, robust connection system that is perfectly suited to 66kV offshore wind farms,” said Dr Peter Muller, Head of Renewables at PFISTERER.

“The SEANEX Connection System has helped us simplify our fabrication and delivery activities by providing a clear interface point between the inter-array cables and the turbine, accelerating the project execution and saving time and costs while providing a permanently robust and secure connection,” commented James Allan, Lead Engineer – Array Cables of Seagreen/SSE Renewables, summarising the advantages.


“The connection system will provide an easier, quicker, cost efficient and safer approach to connect the wind turbine HV network to the array cable infrastructure in a pluggable variant. SEANEX ensures an end-to-end pretested configuration, allowing the possibility to test the entire array cable infrastructure prior to turbine installation, and will last as long as the turbine.

It will also reduce the time for connecting the individual wind turbine generators (WTGs) to the array network, and still allow a primary gas-insulated switchgear in the transition piece to become redundant since it is directly connected to the WTG HV switchgear. It feels like plugging in your extension cord at home on a bigger scale,” explains Stephan Kremers, Project Manager at Vestas.

As the wind turbines are installed, the pluggable connection between the submarine cable and the tower cable allows the project partners’ individual construction phases to be clearly separated. In addition, the 39cm long SEANEX cast resin joints are designed to be more flexible handling during offshore installation process.

They are solid-insulated and therefore SF6 gas free, resistant to salt water and UV radiation, and submersible. They are suitable for various cable types up to a diameter of 800sqmm.

In the Seagreen project, the XLPE insulated submarine cables are connected to the switchgear via flexible, preassemble and pretested “dropper cables” at sea, when installing the turbine, it is simply a case of plugging the cable into the preassembled joint.

This reduces the offshore installation time. The touch-safe, gas-free and maintenance-free inner cone fitting feature separate mechanical and electrical contacts which are stable in continuous operation under load.

PFISTERER will deliver the SEANEX fittings for the Seagreen project when construction starts.

The Seagreen offshore wind farm is located 27km off the Angus Coast in the Firth of Forth.

It will be developed and operated by Seagreen Wind Energy Limited.

Once constructed, the wind farm will be the largest in Scotland. Phase One will feature 114 MHI Vestas V-164-10 MW turbines and is expected to provide low carbon energy for more than one million homes.

In September 2019, Seagreen secured a 15-year CfD contract awarded by the UK government. SSE Renewables is leading on the development and construction of the first 1,140 MW, supported by Total, and will operate the asset on completion, which is expected in 2022/23.


Thorne & Derrick are national distributors of LV, MV & HV Cable Installation, Jointing, Substation & Electrical Equipment – servicing businesses involved in cabling, jointing, substation, earthing, overhead line and electrical construction at LV, 11kV, 33kV, 66kV and EHV. Supplying a complete range of power cable accessories to support the installation and maintenance of low/medium and high voltage cable systems:

  • Slip-on Cable Terminations
  • Cold-shrink Cable Terminations
  • Heat-shrink Cable Terminations
  • Cable Joints – Heat & Cold-shrink
  • Separable Connectors (Euromold)
  • Surge Arresters & Switchgear/Transformer Bushings