East Anglia TWO Offshore Wind Farm

East Anglia TWO is an offshore wind project being developed by ScottishPower Renewables, a subsidiary of Iberdrola, as part of the wider East Anglia Hub. The wind farm, located off the coast of Southwold in Suffolk, North Sea, will have an operational capacity of up to 960MW, capable of supplying electricity to approximately 950,000 homes.

The development represents an estimated investment of £4bn and forms a key element in the UK’s efforts to expand renewable energy generation. It also aligns with Iberdrola’s strategy to strengthen its offshore wind portfolio in the North Sea.

Project Location

The project is located in the North Sea, around 32.6km from the Suffolk coast and approximately 37.5km from Lowestoft. The onshore infrastructure, including the grid connection, will be constructed near Sizewell in Suffolk. This location was selected based on environmental and technical considerations to enable effective integration with the national transmission system.

Capacity and Infrastructure

With an installed capacity of up to 960MW, East Anglia TWO will consist of up to 75 wind turbines installed across an area of 218.4km². The turbines will feature a maximum blade tip height of 282m above sea level.

Each turbine is designed to generate 14MW of electricity and will use a 236m rotor diameter for optimal offshore performance. Siemens Gamesa’s SG 14-236 DD direct-drive turbines have been selected for deployment.

The project also includes the development of offshore and onshore substations. High-voltage export cables will be installed to transfer electricity from the offshore site to the national grid connection point onshore.

Nexans has been contracted to supply these high-voltage cables, ensuring efficient power transmission, while Hitachi Energy’s high-voltage direct current (HVDC) technology will support stable grid integration.

East Anglia TWO Offshore Wind Farm Development and Timeline

The offshore development area will include wind turbines, up to four electrical platforms linked by platform cables to collect electricity, a construction, operation and maintenance platform, and a meteorological mast.

Subsea inter-array cables will connect the turbines to the offshore platforms, while a maximum of two export cables will transmit electricity to shore. Two cable routing options were identified as preferred routes after considering engineering feasibility and environmental impact.

Onshore development works will begin with establishing a landfall location where Horizontal Directional Drilling (HDD) will be employed to install ducts beneath the seabed and avoid disturbance to the beach.

A minimum setback of 85m from the cliff top is planned to accommodate predicted natural coastal erosion over 100 years. Up to six single-core onshore cables will be buried over a distance of approximately 9km using trenching techniques for most of the route.

Road improvements and modifications will be undertaken to manage construction-related traffic and ensure access for heavy equipment. The onshore substation will occupy a 32,300m² site (190m x 170m) with a maximum building height of 14m and external equipment of similar height, except for lightning protection masts.

The associated National Grid substation will use either an Air Insulated Switchgear (AIS) design with a 6m maximum height and 145m x 310m footprint or a Gas Insulated Switchgear (GIS) design with a 16m maximum height and 120m x 140m footprint.

Additional realignment works will include installing up to one new pylon, three cable sealing end compounds, one cable sealing end (with circuit breaker) compound, and reinforcing existing overhead lines.

East Anglia TWO secured a Contract for Difference (CfD) in July 2022 under the UK Government’s Allocation Round 4. Construction is expected to begin in 2027, with operations scheduled for 2028. The project has an anticipated operational lifespan of 25 years.

Power Purchase Agreements

Electricity from East Anglia TWO will be supplied under the UK Government’s Contract for Difference mechanism. This arrangement will ensure price stability for the renewable energy entering the national grid.

East Anglia Hub

The East Anglia Hub represents a major offshore wind energy complex developed by Iberdrola through ScottishPower Renewables. It consists of three projects: East Anglia ONE, East Anglia TWO, and East Anglia THREE, with a combined capacity of around 2.9GW.

The hub is one of the largest offshore wind initiatives globally and contributes to the UK government’s target of achieving 40GW of offshore wind capacity by 2030.

Once fully operational, the hub is expected to supply enough electricity to power approximately 2.7 million UK homes and create significant employment opportunities during both construction and operational phases.

Contractors Involved

In July 2023, Siemens Gamesa signed a £1bn agreement to supply SG 14-236 DD offshore wind turbines for East Anglia TWO.

Nexans was awarded a contract in October 2023 to manufacture and deliver high-voltage export cables linking the offshore substation to the onshore grid connection point in Suffolk.

HSM Offshore Energy was appointed in November 2023 to design and construct the offshore substation.

Wood Thilsted joined the project in December 2023 to provide detailed engineering and design services across the East Anglia Hub, focusing on optimising offshore infrastructure.

In January 2024, Smulders and Sif were jointly contracted to fabricate monopile foundations and transition pieces. These will be produced at European manufacturing facilities and transported offshore for installation.

Seaway 7 was contracted in February 2024 to handle the transportation and installation of the foundations, deploying heavy-lift vessels for operations.

Cadeler also signed agreements in February 2024 to manage the transportation and installation of foundations and turbines.

Taylor Woodrow was appointed in April 2024 to carry out onshore substation works at the Suffolk site, including civil engineering and construction activities.

In November 2024, Hitachi Energy was selected to supply HVDC technology for grid integration.

OCU Group is responsible for civil engineering works along the overland cable corridor, with assistance from its subsidiary Peter McCormack & Sons.

Horizontal directional drilling will be performed to install cable ducts deep within sea cliffs, enabling a connection between subsea and onshore cables while ensuring minimal visual impact.