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VolkerInfra provides specialist Extra High Voltage (EHV) underground cable design and installation services, predominantly in the renewable energy sector.

We are helping the UK move towards an energy-secure future and supporting the transition to greener energy to reach net-zero by 2050. We help clients achieve a cleaner and more efficient electricity transmission network by connecting new offshore and onshore wind farms to the national grid, delivering underground cabling within substations and installing cross country underground cables and between country interconnectors.

We employ in-house cable system designers, CAD technicians, cable engineers, temporary works designers, jointing technicians, cable installation and construction experts.

During the preconstruction phase, our design and engineering teams offer bespoke designs for each installation meeting the client’s specific requirements and ensuring that the performance and lifetime expectance of the cable system is not compromised. We call upon our extensive experience and expertise to determine the most efficient and cost-effective conductor and material size, earthing design, laying configuration, and installation techniques. Our designs are verified by manufacturers and third-party consultants, as required, and to suit our customers’ requirements.

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Full in-house service

We provide a full in-house service for the delivery of all civils and excavation activities associated with the installation of EHV cabling systems.

A team of highly experienced and specialist employees safely and efficiently delivers the works by using clear site-specific drawings and information, supported by a robust quality management system and our in-house design team. Our specific services include:

  • Cable management ducts and troughs with specific thermal and mechanical loading requirements.
  • Cable sealing end structures and their associated concrete bases designed to withstand the anticipated mechanical forces.
  • Deep trenching and horizontal directional drilling works required to avoid underground obstacles.
  • Specialised mid circuit joint bays and transition joint bays to meet the specific cable system design requirements, surrounding geotechnical environment, local hydrology and cable jointers requirements.

Our clients

We collaborate with the UK’s leading energy suppliers and their delivery partners.

We have successfully installed cables for some of the leading clients in the power sector, such as National Grid, Ørsted, Siemens, and GE Grid Solutions. We are a cable installation partner on National Grid’s £1.5 billion Electricity Construction Framework. Our scope covers new build undergrounding routes, route replacement and route decommissioning.

We have delivered the onshore cabling scope associated with some of the UK’s largest offshore wind farms in recent years, including Hornsea 2 and Moray East. On the Hornsea 2 project in Lincolnshire, we completed all the civils works associated with the 38km onshore cable route. This included installing underground circuits within a 40m-wide construction corridor, consisting of three 220kV export cables and fibre optics. We have recently been appointed to fulfil the same role on Hornsea 3 – the next stage in the programme that will supply 1.3 million UK homes with clean energy generated by North Sea wind.