The network in East Anglia today

A large loop runs from Walpole in the north to Pelham and Rayleigh/Tilbury in the south, via Norwich and Bramford​. Two 400,000 volt (400 kV) overhead lines connect Sizewell B, and a decommissioned 132,000 volt (132 kV) overhead line used to connect the now decommissioned Bradwell A​ nuclear power station. Historically there was relatively limited generation and low consumer demand in East Anglia when compared to other parts of the country.

Current generation and demand

The amount of generation in the region has historically been relatively low compared to other parts of the country.

Sizewell B provides nearly a third of the overall generation total for the region, whilst a substantial contribution also comes from offshore wind farms, such as Dudgeon off the Norfolk coast.

910 MW of generation also connects in the region via the UK Power Networks lower voltage distribution network.

All of these generation sources help keep the lights on for millions of people and power homes and businesses across East Anglia and beyond.

Demand for electricity in the region has been falling slightly in recent years. Peak demand on the network is forecast this year at 1,346 MW. However, demand across the UK as a whole continues to rise.

How power is transported

Each line of pylons on the network carries two electrical circuits. There are four circuits connecting to and from the region – two circuits on the overhead line between Walpole and Norwich to the north and two on the line running west out of Bramford to Twinstead Tee.

The network is planned and operated under a set of standards designed to ensure there are no widespread electricity supply interruptions, even if two circuits are out of service.

Taking the standards into account, the network today in East Anglia has around 3.5 GW of transfer capability out of the region, with two of the four circuits connecting the region to the wider network out of service.

The network as it is today has been able to meet the needs of the region and transfer power out of East Anglia, but with a huge increase in renewable and low carbon generation coming, that is about to change.

Moving towards net zero

As we move toward cleaner, greener sources of energy, and more of the energy we use comes from offshore wind, nuclear power, and trading energy through interconnectors with other countries across the North Sea, the demand on the electricity network is set to significantly increase.

The UK has set a world-leading target to tackle climate change, which is to achieve net zero carbon emissions by 2050.

The network in East Anglia will play a vital part in helping to meet this goal, with 60% of upcoming offshore wind generation set to come ashore along the east coast.

Future generation

While the network in East Anglia can accommodate the level of generation and demand that there is today, this situation will change over the next decade with the increase in the amount of electricity set to come from offshore wind, interconnectors and nuclear power.

By the end of this decade, there will be significantly more generation than the current network is capable of accommodating.

National Grid ESO assesses how much energy needs to be carried on the network in the future, and anticipates that up to 17.9 gigawatts of transmission network capability is needed by the end of this decade. This far in excess of the 3.5 GW of transfer capability in the existing network.

Contracted generation in East Anglia from 2021-2030

2021 (existing)

Generation (total) 4,100 MW; Nuclear 1,230 MW; Offshore wind 2,409 MW; Gas 420 MW; Biomass 41 MW.

Forecast demand 1,346 MW

Project nameCustomerConnection siteContracted generation (MW)StatusType of generation
Sizewell BEDF Energy Nuclear Generation LtdSizewell1230BuiltNuclear
DudgeonDudgeon Offshore Wind LtdNecton400BuiltOffshore wind
Greater GabbardGreater Gabbard Offshore Wind LtdLeiston500BuiltOffshore wind
GalloperGalloper Wind Farm LtdLeiston350BuiltOffshore wind
East Anglia 1East Anglia One LtdBramford680BuiltOffshore wind
Sheringham ShoalScira Offshore Energy LtdNorwich (connected to local distribution network)315BuiltOffshore wind
Gunfleet SandsGunfleet Sands LtdBramford (connected to local distribution network)99.9BuiltOffshore wind
Gunfleet Sands IIGunfleet Sands II LtdBramford (connected to local distribution network)64BuiltOffshore wind
Great YarmouthRWE Generation UK plcNorwich

(connected to local distribution network)

420BuiltGas (CCGT)
ThetfordEPR Thetford LtdBramford (connected to local distribution network)41BuiltBiomass

2022

Generation (total) 4,448.5 MW; Nuclear 1,230 MW; Offshore wind 2,409 MW; Gas 768.5 MW; Biomass 41 MW.

Forecast demand 1,303 MW

Project nameCustomerConnection siteContracted generation (MW)StatusType of generation
Yare Power LtdNorwich49.5Consents approvedGas (CCGT)
Progress PowerProgress Power LtdYaxley299Consents approvedGas (CCGT)

2023

Generation (total) 5,748.5 MW; Nuclear 1,230 MW; Offshore wind 3,609 MW; Gas 768.5 MW; Biomass 41 MW; Energy storage 100 MW

Forecast demand 1,287 MW

Project nameCustomerConnection siteContracted generation (MW)StatusType of generation
East Anglia 3East Anglia Three LtdBramford1200Consents approvedOffshore wind
Bramford TertiaryPivoted Power LLPBramford49.9Awaiting consentsEnergy storage
Bramford TertiaryBramford Green LtdBramford49.9ScopingEnergy storage

 2024

Generation (total) 10,015.5 MW; Nuclear 1,230 MW; Offshore wind 4,469 MW; Gas 2,468.5 MW; Interconnector 1,600 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,280 MW

Project nameCustomerConnection siteContracted generation (MW)StatusType of generation
East Anglia 2ScottishPower Renewables (UK) LtdFriston (to be established)860Awaiting consentsOffshore wind
Kings Lynn BEP UK Power Development LtdKings Lynn1700Consents approvedGas (CCGT)
EurolinkNational Grid Interconnector Holdings LtdFriston (to be established)1600ScopingMulti-purpose interconnector
Bramford TertiaryPivoted Power LLPBramford7.1ScopingEnergy storage
Bramford TertiaryBramford Green LtdBramford49.9ScopingEnergy storage
NorwichPivoted Power LLPNorwich49.9Consents approvedEnergy storage

2025

Generation (total) 13,215.5 MW; Nuclear 1,230 MW; Offshore wind 7,669 MW; Gas 2,468.5 MW; Interconnector 1,600 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,287 MW

Project nameCustomerConnection siteContracted generation (MW) 

Status

Type of generation
Vanguard EastNorfolk Vanguard East LtdNecton1200Consents approvedOffshore wind
Hornsea 3Orstead Hornsea Project Three LtdNorwich2000Consents approvedOffshore wind

2026 – same as 2025 (no additional projects connecting)

Generation (total) 13,215.5 MW; Nuclear 1,230 MW; Offshore wind 7,669 MW; Gas 2,468.5 MW; Interconnector 1,600 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,298 MW

2027

Generation (total) 16,775.5 MW; Nuclear 1,230 MW; Offshore wind 9,729 MW; Gas 2,468.5 MW; Interconnector 3,100 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,312 MW

Project nameCustomerConnection siteContracted generation (MW) 

Status

Type of generation
East Anglia 1(N)East Anglia One LtdFriston (to be established)860Awaiting consentsOffshore wind
BoreasNorfolk Boreas LtdNecton1200Consents approvedOffshore wind
NautilusNational Grid Interconnector Holdings LtdFriston (to be established)1500ScopingMulti-purpose interconnector

2028

Generation (total) 19,175.5 MW; Nuclear 1,230 MW; Offshore wind 10,729 MW; Gas 2,468.5 MW; Interconnector 4,500 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,351 MW

Project nameCustomerConnection siteContracted generation (MW)StatusType of generation
Hornsea 3Orstead Hornsea Project Three LtdNorwich1000Consents approvedOffshore wind
AminthAminth Energy LtdNorwich1400ScopingInterconnector

2029

Generation (total) 21,193.5 MW; Nuclear 2,900 MW; Offshore wind 11,077 MW; Gas 2,468.5 MW; Interconnector 4,500 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,387 MW

Project nameCustomerConnection siteContracted generation (MW)StatusType of generation
Sizewell CEDF Energy Nuclear Generation LtdSizewell1670Awaiting consentsNuclear
Five EstuariesRWE Renewables UK Swindon LtdCoastal Node (to be established)348ScopingOffshore wind

 2030

Generation (total) 24,459.5 MW; Nuclear 5,666 MW; Offshore wind 11,577 MW; Gas 2,468.5 MW; Interconnector 4,500 MW; Biomass 41 MW; Energy storage 207 MW

Forecast demand 1,413 MW

Project nameCustomerConnection siteContracted generation (MW) 

Status

Type of generation
Sizewell CEDF Energy Nuclear Generation LtdSizewell1670Awaiting consentsNuclear
Bradwell BBradwell Power Generation CoBradwell1096ScopingNuclear
North FallsSSE Renewables Services (UK) LtdCoastal Node (to be established)500ScopingOffshore wind

 

Increasing the capability of the existing network

Before we consider building new parts of the network we first must consider whether we can achieve more capability by upgrading parts of the existing network.

In the first half of the decade that’s exactly what we will be doing.

We will be installing power control devices at key substations in the region – at Pelham, Rye House and Waltham Cross, to make more use of an existing route to the west of the region.

We will be increasing the voltage of a section of line from Waltham Cross south into London to 400kV to increase the capability of that part of the network on into the capital.

We will be re-wiring existing overhead lines with larger diameter conductors that can carry more power – for example on the existing overhead lines from Bramford to Braintree to Rayleigh to Tilbury.

Making these improvements increases the capability of the existing network to around 6 GW. But it is still insufficient to deliver up to 17.9 GW of export capability that the National Grid ESO advises is required to deliver cleaner, greener energy to homes and businesses beyond the region in line with Government ambitions.

These upgrades alone won’t provide enough additional capacity, so we also need to build new parts of the network between Bramford and Twinstead, a subsea link between East Anglia and Kent, and between Norwich in the north of the region to Tilbury in the south.

Reinforcing the network between Bramford and Twinstead

A new route is needed between Bramford and Twinstead Tee because there are three double circuit overhead electricity lines carrying power into Bramford – one from Norwich to the north and two from Sizewell to the east – but west of Bramford out to Twinstead Tee, there is only one carrying power out of the region.

With substantial new sources of energy connecting in the region by the end of the decade, the existing overhead line west of Bramford would be overloaded, which would fall short of the Security and Quality of Supply Standards.

Beyond Twinstead Tee there are two routes out of the region – one west to Pelham and one south to Braintree-Rayleigh-Tilbury.  Adding a double circuit route between Bramford to Twinstead will remove that bottleneck on the network and make more efficient use of the two routes west and south of Twinstead Tee.  Reinforcing the network between Bramford and Twinstead will create two independent double circuit transmission routes west of Bramford – one from Bramford to Pelham and one from Bramford to Braintree to Rayleigh to Tilbury.