London Power Tunnels phase 1

Discover more about the first phase of the London Power Tunnels project


In February 2011, National Grid embarked upon a seven-year, £1bn infrastructure project to rewire the Capital, the first major investment in the electricity transmission system in London since the 1960s. The project, known as London Power Tunnels, saw the construction of 32kms of underground tunnels, running from Hackney in the east to Willesdon in the west, and from Kensal Green to Wimbledon in the south. The newly build 10 transmission circuits can now carry some 20% of the Capitals electricity demand and stretched out they would run all the way around the M25.

Key facts

  • The depth of the tunnels varies along the route being between 20 metres and 60 metres down. The tunnels go under Tube lines, canals and rivers.
  • 192km of 400kV cable has been installed in the tunnels, along with 30km of 132kV cable.
  • There were 14 access shafts dug to support the tunnelling work, which was completed in 2015.
  • Over 700 people were employed at the busiest time on the project, with forty apprenticeship tunnelling roles created over the project’s lifespan. In total, it took over 6 million people hours to complete LPT.
  • National Grid recycled 99% of the material excavated during the construction of the tunnels, with the excavated 500 cubed metres of London clay enough to fill Arsenal’s Emirates stadium, which is just down the road from the project’s Highbury substation.

Community Outreach

We are proud of the positive legacy we left with phase 1 of the London Power Tunnels project where we engaged with over 30,000 students; it is our aspiration to build on this through phase 2.

  • Through our long-term partnership with youth charity City Year UK, we sought to inspire the next generation of engineers and encourage thousands of children’s interests in STEM subjects through school visits and interactive educational sessions.
  • Alongside the Tottenham Hotspur Foundation, National Grid helped to deliver sport and physical activity projects to the community, providing £75,000 of funding to three local groups in Haringey.
  • We teamed up with Daubeney Fields Forever, a collection of local community groups in Hackney, to help transform a disused car park into a pocket-sized park.
  • During the summer months, National Grid teamed up with the National Citizen Service (NCS) through the The Challenge programme in Ealing. As part of the programme, which looked to connect and inspire people to strengthen their communities, National Grid hosted various groups of 15-17 year-olds at the London Power Tunnels headquarters in Willesden, providing a tour of the site and a careers talk from the senior project managers. The National Grid team also provided feedback to groups of young people on their campaign ideas to promote social cohesion in their local communities.
  • National Grid created the Energy Education Centre, in the Willesden Junction area of north-west London, as a free facility to help young people understand energy and to strengthen their interest in science. Visiting groups learned about the vital role of energy in our lives, how it is made and delivered, the issues around fossil fuels and the importance of renewable energy.

London Power Tunnels phase 1 route map