About the Bramford to Twinstead Reinforcement

National Grid Electricity Transmission will reinforce the electricity transmission network between Bramford substation in Suffolk and Twinstead Tee in Essex through the construction of a new overhead line and underground cable link.

With new offshore wind generation, a new nuclear power station at Sizewell C and greater interconnection with countries across the North Sea being proposed, there will be a huge increase in the amount of renewable and low carbon electricity generation connecting along the East coast in the years ahead.

While our existing high voltage electricity network in East Anglia has been sufficient until today, it doesn’t have the capability needed to reliably transport all the energy that will be connected by 2030 while working to the required standards.

This will involve constructing up to 18 km of overhead line and around 11 km of underground cable (through the Dedham Vale National Landscape and in the Stour Valley). Strengthening the network here is vital to deliver cleaner, greener electricity efficiently, reliably, and safely and to support the UK’s move to Net Zero.

Construction work on a grid supply point substation at Butler's Wood started earlier in 2024. Our application for development consent was granted by the Secretary of State for Energy Security and Net Zero in September 2024, with construction works on the rest of the reinforcement due to start in the coming months.
 

Why is this happening?

East Anglia’s 400,000 volt (400 kV) electricity transmission network was built in the 1960s. It was built to supply regional demand, centred around Norwich and Ipswich. With the growth in new energy generation from offshore wind, nuclear power and interconnection, there will be much more electricity being generated in East Anglia than the network can currently accommodate.

The network needs upgrading and capability adding to be able to transport cleaner, greener energy from where it is generated to where it is consumed.

The Bramford to Twinstead Reinforcement is just one of several electricity network reinforcements that are needed to ensure the electricity transmission network is fit for the future.