Hornsea 3 blade production under way as Hull factory cuts UK’s largest turbine blades

Hornsea 3 blade production has begun at the Siemens Gamesa factory in Hull, marking a concrete step forward for what is shaping up to be one of the most capital-intensive offshore wind projects ever attempted in the UK, with an estimated investment of £8.5 billion, according to Black Ridge Research.

The blades rolling off the Hull production line measure 115 metres, which Siemens Gamesa says makes them the largest ever manufactured in the UK. Each one is destined for an SG 14-236 turbine, power-boosted to 15MW. Multiply that out: 197 turbines, three blades apiece, and the logistics task alone is considerable before a single rotation generates a watt of electricity.

What Hornsea 3 blade production means for the project’s scale

The farm itself will sit approximately 120 km off the Norfolk coast in the North Sea, according to Black Ridge Research, and is owned jointly by Ørsted and Apollo-managed funds. Once operational, the project is projected to deliver more than 2.9GW of generating capacity, enough to power more than 3.3 million UK homes.

That puts it well ahead of Hornsea 1 and Hornsea 2 combined. Those two predecessors are together capable of generating enough power for 2.5 million UK homes. Hornsea 3 alone, if it delivers on its nameplate, would surpass that figure by a substantial margin. Whether it does will depend on factors the press release does not address: load factors, grid connection reliability, and the long-term performance of a turbine model whose 15MW power-boost configuration is still accumulating an operational track record.

The ownership structure is worth noting. Ørsted’s co-ownership with Apollo-managed funds reflects a now-familiar pattern in large-scale offshore wind: developers sharing balance-sheet exposure with institutional capital to manage the eye-watering upfront costs that a £8.5 billion price tag represents. That figure does not appear in Ørsted’s own announcement, but it sits in publicly available project assessments.

Hull’s industrial role and the local employment case

Siemens Gamesa’s Hull facility employs more than 1,400 local people and previously produced blades for both Hornsea 1 and Hornsea 2, giving the site a continuous supply-chain role across the entire Hornsea Zone. That continuity matters for the industrial policy argument that offshore wind can anchor skilled manufacturing employment in coastal communities.

Energy Minister Michael Shanks framed the milestone in unambiguously political terms. ‘This is what good growth in every postcode looks like, world-leading offshore wind blades built in Hull, powering clean homegrown electricity for millions of homes from off the coast of Yorkshire,’ he said.

The politics are not wrong, but they do flatten the engineering reality. Luke Bridgman, Managing Director of Hornsea 3 at Ørsted, was closer to the substance: ‘These massive blades reflect how offshore wind energy continues to develop. This impressive feat of engineering is another part of the jigsaw that will help to power the UK.’

Darren Davidson, UK Vice President for Siemens Energy and Siemens Gamesa, pointed to the technology trajectory. ‘At 115 metres, these are the largest blades ever manufactured in the UK, reflecting how far offshore wind technology has advanced in recent years,’ he said. That claim is credible: the blades being made in Hull for Hornsea 1, which came online in 2019, were considerably shorter. The step-change in rotor diameter is a direct driver of the capacity uplift, since swept area scales with the square of blade length.

Blade production starting is a supply-chain milestone, not a commissioning one. The turbines still need to be transported, installed and commissioned some 120 km offshore before any of this translates into electrons on the grid. With a project at Hornsea 3’s scale and investment level, the gap between first blade and first power can run to years. The Hull factory has done its part; the hard work at sea is still ahead.