National Grid Energizes Third Circuit of $1.34 Billion London Power Tunnels 2 (LPT2) Project

The newly energized transmission circuit serves around 340,000 properties in South East London, supplying power onwards to UK Power Networks’ distribution network through National Grid’s substations at New Cross and Hurst.

Dec. 19, 2025

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National Grid has announced energization of third circuit of $1.34 billion London Power Tunnels 2 (LPT2) project.

The first of two new circuits connecting National Grid’s New Cross substation in Southwark with its Hurst substation in Bexley is operational, running for 18 km beneath South London through tunnels up to 50 meters deep. The new link replaces one of two buried cables, with the other to be replaced when the second New Cross-Hurst circuit is operational in 2026.

At almost 22 km, the original links have been the longest AC transmission cables on the entire England and Wales network, an accolade passing to the Elstree to St John’s Wood cable circuit in the north of the city. The newly energized transmission circuit serves around 340,000 properties in South East London, supplying power onwards to UK Power Networks’ distribution network through National Grid’s substations at New Cross and Hurst.

Energization of the first two of LPT2’s circuits took place between Hurst and Crayford in August 2024 and March 2025, along a 2.5 km route forming the project’s most easterly section.

In total the LPT2 project, which began in 2019, covers 32.5 km across seven South London boroughs from Wimbledon to Hurst. It has been delivered by National Grid in partnership with HOCHTIEF-MURPHY Joint Venture (HMJV), Taihan, Balfour Beatty and Linxon.

The LPT2 project involves:

32.5 km of tunnels across seven South London boroughs between Wimbledon and Hurst.
200 km of high voltage cable installed in the tunnels – enough to stretch from London to Cardiff, or circle around the M25.
30 m average tunnel depth, with the route crossing under rivers and rail lines, including under the Northern and Victoria tube lines and the DLR.
147,000 students reached through a schools program tackling social mobility, closing STEM skills gaps, and opening green energy career pathways for underrepresented youth.
$701,400 in funding to local community groups and organizations through a grant program, including a Lambeth food growing charity and Bexley Cricket Club.
5 million working hours from over 3,000 people across the project since 2019.

The current London Power Tunnels project is the second phase to reinforce the capital’s electricity network in readiness for growing electricity demand. It follows the completion of the first phase in 2018, a seven-year, $1.34 billion project to construct 32 km of tunnels and two new substations to rewire the network in North London.