East Anglia Three: Foundations In, Turbines Turning — Inside the 1.4 GW Build and Its Spanish Steel Backbone

East Anglia Three (EA3) has moved through the phase where most heavy fabrication and marine installation decisions are still open. All 95 monopile foundations and all 95 transition pieces are in the seabed, Seaway7 has completed the final inner-array cable lay — 95 cables totalling more than 240 km, loaded, laid and pulled into the foundations — and the Siemens Gamesa turbine installation campaign, which began in April, is the remaining large offshore activity before commissioning. Testing, termination and trenching work continues on the array cables.

The practical commercially relevant conclusion for suppliers: the primary steel and marine construction procurement is complete. For a steel or fabrication business, EA3 should now be read as a closed reference project and a demand signal — not as an open tender.

What the asset is

EA3 is the largest of the East Anglia Hub projects and, on completion, is expected to supply power equivalent to well over a million homes. It is a template for how a UK Round 3-scale project gets built when the developer keeps engineering and interface risk in-house rather than handing a single contractor an EPCI wrap.

The delivery model: multi-contract, owner-managed

There is no single EPCI contractor at EA3, and the "who is the EPC?" question does not have a clean answer because none was appointed. ScottishPower Renewables, as the Iberdrola vehicle, let separate large packages and retained interface management. The marine package that comes closest to an EPCI scope went to Seaway7: transport, logistics and installation of the 95 monopiles, seabed preparation, scour protection, and engineering, supply and installation of the inner-array cable system. Turbine transport and installation was a separate firm contract with Cadeler, and turbine supply came from Siemens Gamesa.

That structure matters beyond EA3. It spreads marine risk across specialist vessels and contractors, and it means the developer — not a lead contractor — carried the sequencing risk between foundations, cables and turbines. At EA3 that sequencing has held: foundations first, array cable closed out behind them, turbines following on.

The steel story is already written — and it is Spanish

Most of the foundation steel was fabricated in Spain, split between two suppliers and one transition-piece fabricator:

• Navantia Seanergies–Windar Renovables joint venture built 45 monopiles, each roughly 84 m tall, 10.6 m in diameter and about 1,800 tonnes. The build was reported at around 900,000 working hours over a 15-month execution period.
• Haizea Wind Group, at its Port of Bilbao facility, built 50 monopiles under a contract signed in 2023 worth more than €200 million and covering materials supply, manufacturing-process engineering and monopile production — a full-scope fabricate contract rather than tolling. Haizea has since positioned itself as a leader in monopiles for turbines above 15 MW.
• Windar also produced all 95 transition pieces.

At roughly 1,800 tonnes per monopile, the monopile order alone represents on the order of 170,000 tonnes of fabricated steel across the two suppliers, before transition pieces and secondary steel are counted. That is the scale of demand a single 1.4 GW project generates — a useful benchmark for fabricators modelling the UK pipeline.

Two details worth flagging for anyone using EA3 as a reference case. First, foundation fabrication ran 2023–2025; delivery and installation wrapped in the first half of 2026. Second, the ownership of the project changed after those contracts were signed: Masdar and Iberdrola announced a €5.2 billion deal for Masdar to take 50% of EA3 from ScottishPower Renewables, with the stake transferring in July 2025. Masdar therefore inherited, rather than placed, the foundation supply contracts.

Financing and revenue: the commercial frame

Financial close came in July 2025 on a £3.6 billion (about €4.1 billion) project financing from 23 banks plus the Danish export credit agency EIFO. Masdar described it as its largest-ever facility; the book was reportedly oversubscribed by more than 40%. Total project cost is put at roughly €5.2 billion, a figure that should be preferred to the lower, inconsistent estimates sometimes quoted.

Revenue rests on two legs: a 15-year CPI-linked Contract for Difference awarded across the UK's AR4 and AR6 allocation rounds, and a power purchase agreement with Amazon signed in 2024. That combination — subsidy floor plus corporate offtake — is characteristic of late-allocation-round UK offshore wind, and it is the commercial backdrop against which the remaining construction risk is being run.

What is actually left

The remaining programme is narrow and largely mechanical: complete turbine installation, finish array-cable testing, termination and trenching, commission the export and array systems, synchronise to the grid and reach commercial operation, targeted for end-2026. Grid connection and commissioning, not fabrication, are now the critical path.

For steel and industrial suppliers, EA3 offers little in the way of open opportunity. Any forward-looking avenue — maintenance, repair, potential repowering or expansion within the East Anglia Hub — is speculative and not evidenced by current project disclosures; it should not be treated as a pipeline item. The more defensible reading is that EA3, together with its Hub siblings, demonstrates sustained UK demand for very large monopiles that the domestic fabrication base has so far largely not captured. That is the strategic question the project leaves open, not a tender to chase.

Reading the timing carefully

The cable installation completion and foundation milestones sit in mid-to-late 2026, while the turbine campaign that began in April is widely reported as due to finish this year. Readers tracking EA3 should anchor on the developer's own sequencing and the vessel movements of Seaway Ventus (foundations), the Cadeler fleet (turbines) and the array-cable spread, rather than on any single trade-press date. Where sources differ — for example on the exact offshore distance, quoted as 69 km by Seaway7 — the developer and installation contractor figures are the more reliable.

The takeaway

EA3 is best understood now as a nearly-complete construction reference, not an open procurement. Its foundation package shows how much steel a 1.4 GW array consumes, how it was sourced from Spanish fabricators on full-scope contracts, and how a multi-contract developer model sequenced foundations, cables and turbines without an EPCI wrap. The value for industry professionals lies in using those facts to calibrate the next UK projects — not in looking for work on this one.