π Project Overview
Hornsea One was the world's first gigawatt-scale offshore wind farm when it was fully commissioned in 2019. Located in the southern North Sea, its 174 Siemens Gamesa 7 MW turbines stand approximately 190 metres to blade tip. The project transformed the UK's offshore wind ambitions and proved that gigawatt projects were commercially viable, paving the way for Hornsea Two, Three and the Dogger Bank complex.
Site Schematic
Schematic diagram β not to scale. Illustrative layout based on project specifications.
β‘ Key Facts
π§ Technical Specifications
| Capacity (MW) | 1,218 MW |
| No. of turbines/units | 174 |
| Turbine / unit model | Siemens Gamesa SG 7.0-154 |
| Unit capacity | 7 MW each |
| Rotor diameter | 154 m |
| Hub height | 102 m |
| Foundation type | Monopile |
| Water depth | 23β28 m |
| Distance from shore | 120 km |
| Site area | 407 kmΒ² |
| Annual output | 4,200 GWh/year |
| Homes powered | 1,000,000 homes |
π Grid Connection & Infrastructure
| Grid connection point | Killingholme, Lincolnshire (onshore substation) |
| Voltage | 400 kV National Grid connection |
| Export cable | Three HVAC 220 kV cables, ~120 km |
| CfD held | Yes β Allocation Round 1Β£120/MWh (2012 prices) |
π’ Development & Ownership
| Developer | Γrsted |
| Owner / operator | Γrsted (50%), Global Infrastructure Partners (50%) |
| Year consented | 2014 |
| Construction started | 2018 |
| Commissioned / target | 2019 |
| Capex estimate | ~Β£4.2 billion |
| Location | 120 km off the Yorkshire coast, between Hornsea and Withernsea |
| Region | North Sea |
| Coordinates | 53.92Β°N, 1.97Β°E |
π Project Timeline
πΏ Environmental & Planning
Hornsea One went through one of the most detailed EIAs ever conducted for a UK offshore project. The site was selected to minimise impacts on migratory birds, with exclusion zones around key navigation routes. The export cable route was designed to avoid sensitive seabed habitats. Post-construction monitoring shows the site is becoming an artificial reef habitat.