Central to the UK’s decarbonisation and net zero ambitions lies a robust, resilient and future-ready electricity grid.
Our team of electrical transmission and distribution specialists act as expert strategic partners, offering distribution FEED studies, consulting services, and overhead lines, cables and substation development, as well as construction and commissioning.
Drawing on decades of experience in major infrastructure projects in sectors including energy and power (London Tunnels, carbon capture for the East Coast Cluster), transportation (HS2, Crossrail), and water (Tideway, Anglian Water’s Strategic Pipeline Alliance), we’re bringing predictable, best-in-class capabilities, deep technical experience and end-to-end project delivery to drive the UK’s transition in high-voltage infrastructure and power the UK for future growth.
Our transmission and distribution services:
We’re highly experienced at delivering complex tunnelling programmes for a variety of infrastructure sectors, including energy, water, and transportation. We use production thinking and the latest automated technology to minimise disruption and unlock efficiencies in space-constrained environments. Our expertise includes the installation of mechanical, civil and electrical services, and assurance.
We design and install underground cables and cable tunnel systems that carry high voltage transmission circuits safely and reliably, connecting power sources to urban areas and heavy industry.
We integrate and upgrade high voltage transmission systems across the UK, including cross-country cable corridors and overhead line turn-ins at substations, with a focus on constructability, environmental sustainability, biodiversity, and community engagement.
We design, build, test and commission high voltage transmission and distribution substations, up to 400kV. Our focus is on safety, resilience, and long-term asset performance.
We have a long history of providing integrated design services that bring in engineering and constructability at the earliest possible stage, reducing risk and improving efficiency across all elements of transmission and distribution infrastructure.
We manage and deliver multi-disciplinary infrastructure programmes across live networks and complex, regulated environments. By bringing together our unique mix of construction, consultancy, engineering and digital services, we work strategically with our customers and suppliers to meet critical national needs by transforming the performance of the infrastructure that connects, protects and powers people's lives.
From early-stage feasibility to handover, our team of electrical transmission and distribution specialists act as expert strategic partners, offering transmission and distribution FEED studies, consulting services, and overhead lines, cables and substation development, as well as construction and commissioning.
We work with customers across the energy transmission and distribution landscape, including National Grid, SSE, Scottish Power and progressing our collaboration with other distribution networks across the UK as well as engaging with major OEMs.
Production Thinking is embedded in Costain’s delivery of critical infrastructure. Combining modern methods of construction (MMC) with new technologies and materials, lean techniques, digital tools and smart decision-making, Costain’s production thinking approach boosts productivity and efficiency across its infrastructure projects.
The UK is facing power challenges that haven’t been seen for generations.
On the one side, demand for electricity is increasing, caused by a growing population, changing behaviours and the electrification of transport, heating and industrial activities.
At the same time, the UK is benefitting from an increasing supply of power from renewable sources, including nuclear, wind and solar. The low-carbon electricity that’s being generated requires transmission and distribution over hundreds of kilometres, from coastal sources to the homes, factories and urban areas that rely on it.
The UK’s National Grid, as part of the Great Grid Upgrade, is aiming to respond to the UK’s growing demand for electricity, which is expected to increase by 50% by 2035 and double by 2050. It is targeting a 50GW increase in clean energy by 2050.
The challenge is clear: connect gigawatts of clean power from renewable sources to industrial hubs and population centres, whilst improving grid resilience and capacity by upgrading ageing assets.
Upgrading transmission infrastructure is not just about meeting energy targets. It’s about building resilience into an essential system and creating the conditions for long-term prosperity.
Every new substation, cable tunnel and high voltage connection enables economic growth and better energy connections for industry and people. It also accelerates decarbonisation by integrating low-carbon power generation, while at the same time unlocking regional investment through the creation of jobs and development of skills across the country.
From planning and design to construction and commissioning, Costain acts as a trusted delivery partner to both private and public sector organisations.
Our high voltage transmission, tunnelling and distribution expertise in action:
London Power Tunnels: delivering a 32km electricity superhighway
Instead of digging up and replacing the old cables that are buried under the roads – adding years of roadworks to London’s already busy transport network – the joint venture created easily-accessible spaces that allowed cable installation and maintenance to be undertaken without any disruption to the public.
In addition, the management and movement of more than 400,000m3 of excavated soil (spoil) from the tunnels had a significant, positive environmental and financial impact to the project. The team identified an opportunity to reuse the spoil within National Grid’s network of disused gas holders that required remediation. This industry leading approach prevented 340,000m3 (85%) of excavated spoil and 97.6% of all other waste from going to landfill.
London Power Tunnels: a new 32km electricity superhighway"The London Power Tunnels project is seen as major success story within National Grid. Costain has been the key contract partner for the London Power Tunnels project since 2010 constructing vital assets in challenging environments."
Gareth Burden National Grid, Senior Project Manager
Anglian Spa: reducing the amount of water used in pipeline commissioning
Costain, as part of the Strategic Pipeline Alliance (SPA) tasked with delivering hundreds of kilometres of new, interconnecting pipelines, is combatting the impact of climate change to keep fresh, clean water flowing for Anglian Water’s customers.
Since its appointment in 2020, Costain and its Alliance partners have had a highly successful and collaborative track record, deploying production thinking techniques that drive efficiency and sustainability. This includes cutting water use by 85% and reducing the project's environmental impact through adopting a low water commissioning strategy that used compressed, dry and clean air to disinfect pipes.
Costain and its SPA partners recently secured an extension to deliver an additional 20km of pipeline for Anglian Water by 2030, building on the existing interconnector work and taking the total length of the strategic pipeline to 580km.
Anglian Water low water commissioning
Tunnel vision - how a pioneering robotic and AI solution is transforming tunnel installation
An automated system has the potential to revolutionise the installation of mechanical and civil services in tunnels; that’s what makes our successful trials of ATRIS - Automated Tunnel Robotic Installation System – so significant.
ATRIS is an integrated robotic and AI solution that can autonomously select brackets, locate where they need to be mounted along a tunnel wall, and install them.
When combined with a real-time digital assurance system, known as Digitally Assured Tunnel Assets - Information System (DATA-IS), it is possible to create a fully automated tunnel installation and assurance solution that can be deployed in tunnel construction for a variety of sectors including cable tunnelling.
It is expected to increase productivity by 40% due to faster installation, reduce installation costs for new mechanical and electrical (M&E) systems by 30%, and cut construction plant movements by 40% to decrease embodied carbon. It also has huge safety benefits, reducing working at height and in confined spaces and improving safety at the tunnel workface.
Tunnel, vision: how a pioneering robotic and AI solution is transforming tunnel installation
Crossrail – powering the Elizabeth Line
Costain’s joint venture with Alstom and TSO – Crossrail’s largest JV – was engaged to deliver the design, construction, testing and commissioning of the railway systems in the Elizabeth line’s tunnel network across London. This included track, mechanical and electrical systems, overhead lines, equipment within tunnels and ventilation.
Working with Alstom, we also delivered the HV traction power (25kV) and non-traction power (11kV and 22kV) systems. We used digital rehearsals to assure the installation of switch gear in complex station structures, up to six storeys beneath central London. The works included integration and testing of these two systems for the Crossrail programme, which required ongoing engagement and communication with multiple stakeholders, including National Grid.
Connecting London through innovation and collaborationContact
If you want to learn more about Costain’s capabilities in high voltage transmission and distribution infrastructure, please don’t hesitate to reach out to our transmission director, Bruce Tumenta [email protected]