Energy bosses expect electricity demand will surge across London over the coming years
A new substation is being built near Watford(Image: National Grid)
The National Grid is scrambling to boost electricity supply in North West London ahead of five data centres being built. The energy company has announced plans to build a new substation, lay 60km of new cable and upgrade over 200km of overhead line.
Maps of the project show the network will be improved between St John’s Wood and Sundon in Bedfordshire. Network Rail said it will help cope with rising electricity demand across North West London while making sure homes and businesses continue to get reliable power.
A new substation will be built in Letchmore Heath near Watford to make this possible. The existing substation at St John’s Wood will also be reinforced, along with upgrades to Elstree and Sundon substations.
People living near the Letchmore Heath substation will be eligible for a share of £530k to spend on local projects through the government’s community fund. Network Rail is currently working on an electricity upgrade in South London that’s due to finish this year, while another project between Hackney and Pelham in Hertfordshire is due to finish in 2028.

Data centres are springing up across London in response to the surge in artificial intelligence(Image: Hounslow Council)
The National Grid is yet to confirm its timeline for the North West London upgrade. “The project is a nationally significant investment that will strengthen the electricity network, unlock new connections, support regional economic growth and help keep long term energy costs down for consumers,” National Grid project director Joe Senior said.
“Working closely with our delivery partners and supply chain, we’re bringing together substations, cables and tunnels, and overhead line reinforcement in a single programme to deliver the infrastructure needed to power future homes, businesses and digital industries as electricity demand rises.”
Raj Kundan, HMJV project director, added “HMJV are proud to continue supporting National Grid in the delivery of critical national energy infrastructure, bringing our cutting-edge solutions and ‘One Team, One Spirit’ approach. Our team look forward to working in collaboration with National Grid and the enterprise partners to leave a positive legacy for all those connected with the scheme.”
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