Unlocking the next generation of offshore wind: step change to 132 kV array systems

The OWA High Voltage Array Systems project publishes outcomes of a study into the optimal future array voltage level and how the transition can be made most effectively.

HiVAS report cover


The Carbon Trust has published a study in collaboration with the OWA High Voltage Array Systems partners. The primary objectives of the study were to: 

  • Determine the optimum voltage for future array systems
  • De-risk future wind farm projects that will use the new array voltage level
  • Promote the optimum voltage as a global standard
  • Inform wind farm developers, the supply chain, regulators and other relevant stakeholders about when the change to the higher voltage is likely to occur and the critical path to transitioning to the next voltage 

The study involved:

  • Extensive supply chain engagement to raise awareness of the project and to gain insight from the supply chain on technical and engineering factors
  • Reviews of the market, literature, regulations and standards
  • Detailed engineering design studies of high voltage array components
  • Life-cycle cost benefit and risk analysis
  • Review of the impacts of increasing array voltage on cable designs


Publication date: June 2022

Key findings

  • Consensus was reached that 132 kV operating voltage is the cost-optimal next array voltage, with 132 kV offering significant cost savings over 66 kV, even for wind turbines of 14 MW, which are currently available at 66 kV.
  • The study found that that the earliest 132 kV wind farms could be operational is the end of the 2020s, even with immediate proactive work from developers and the supply chain. This highlights the urgency with which the industry must move to make the transition to 132 kV operating voltage.
  • Further work was identified to accelerate the transition to 132 kV. This includes defining robust requirements and standards for 132 kV cables; development, qualification and testing of 132 kV cables; understanding the implications of 132 kV on floating wind; and developing improved cable connectors and testing methods.

About the project 

The project partners are: Carbon Trust, EnBW, Equinor, Ocean Winds, Ørsted, RWE, ScottishPower Renewables, Shell, SSE Renewables, TotalEnergies and Vattenfall. 

TNEI and Petrofac delivered the OWA High Voltage Array Systems project, working closely with the Carbon Trust and the project partners.  They also received inputs from Hellenic Cables and Orient Cable who were contracted to develop concept designs for various high voltage array cables.  All delivery contractors were identified through competitive tender processes. During the project, TNEI and Petrofac also engaged numerous technology manufacturers, array system installers, system operators, regulators, universities, and research institutions.   



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