National Grid Files Plan for Norwich and Tilbury Transmission Line

National Grid PLC has applied before the Planning Inspectorate to build a new transmission network that it says would power up to six million homes and businesses in East Anglia.

The project involves building “a new electricity transmission network upgrade between Norwich Main substation in Norfolk via Bramford substation in Suffolk and a new Tilbury North substation into Tilbury substation in Essex”, National Grid said in a statement on its website.

“The Norwich to Tilbury project will boost electricity capacity across East Anglia, a powerhouse of renewable energy, particularly offshore wind, but a region that has historically had limited transmission infrastructure”.

The proposed line consists of 180 kilometers (111.85 miles) of high-voltage overhead and underground cables.  

National Grid plans to start construction 2027. It expects the work to take around four years.

“As our demand for electricity grows the way we generate electricity is changing. This project will connect our homes, businesses and public services to sources of home-grown British energy which will lower our electricity bills in the long-term and make us more energy independent”, said project director Simon Pepper.

National Grid said the submitted plan accounted for results from public consultations. “Over the past few years, multiple rounds of public consultation have been held with local authorities, elected officials, technical consultees, affected landowners and local communities”, it said.

The Norwich to Tilbury project is part of National Grid’s The Great Grid Upgrade, which consists of 17 major infrastructure projects across England and Wales. These projects would expand and upgrade the network to enable renewables integration.

“These projects are vital to increase Britain’s energy security and meet growing demand for electricity in the years ahead”, National Grid said.

Last year the National Grid Electricity System Operator unveiled a GBP 58 billion ($67.33 billion) plan to raise Great Britain’s generation capacity with renewable energy, with the ultimate goals of meeting growing demand and achieving power decarbonization.

The plan aims to connect a further 21 gigawatts (GW) of wind capacity offshore Scotland to the grid, in addition to a previous plan of 23 GW. “This would mean that there would be 86 GW of offshore wind, making Britain a global leader in offshore wind and floating offshore windfarms”, the system operator said in a statement accompanying the plan. “For comparison, the International Renewable Energy Agency states that there is currently 63GW of offshore wind installed globally.

“In total there will be over 30 GW of offshore wind in Scottish waters compared to 6 GW of peak electricity demand in Scotland in 2035. The plan moves that power to where it can be used – both around Scotland and across Britain”.

The system operator noted in the plan that while Britain achieved significant growth in renewable energy capacity, investment in transmission capacity had not caught up, leading to wastage.

The United Kingdom had 61.37 GW of installed renewable generation capacity as of the first quarter of 2025, according to government data.

“Britain’s electricity needs are set to rise substantially (by up to nearly 65 per cent) by 2035, as our everyday lives become more digitally intertwined and we move towards more electrified heat and transport options”, the system operator said in the new plan.

“Coupled with this, the UK government has set an ambition to have a fully decarbonized electricity system by 2035.

“This means producing more electricity and transporting it in a smarter, cheaper, and greener way. A key part of this is efficiently connecting the offshore wind being built around Great Britain in a coordinated way”.

The government’s goal is to reach 50 GW of offshore wind capacity by the end of the decade.

The new plan also seeks to grow transmission capacity to match the growth in renewable generation.

After assessing about 200 network options, the plan included an “optimized high-level network design”. The design recommended “over three times as much undersea cabling laid compared with new onshore routes, linking electricity being produced in the seas around our shores onto the mainland at appropriate points”.

The system operator also proposed reinforcing grid integration between North East Scotland and North West England through a new arterial transmission route.

“Furthermore, by enhancing the capacity between the west coast and the east coast of England, the links between the primary arterial routes are strengthened”, the plan said. “This increased coast-to-coast connectivity balances power flows across the country, improving security and ensuring that renewable power can always be accessed regardless of where it is generated”.

The system operator has been renamed National Energy System Operator after National Grid sold it to the government last year to create an independent operator.

To contact the author, email jov.onsat@rigzone.com