Hornsea One is a 1.2 GW offshore wind farm located around 120 km off the Yorkshire coast in the North Sea. Developed by Ørsted, construction began in 2018 and the first turbines supplied power in early 2019. All 174 Siemens 7 MW turbines were installed by October 2019, and the project was fully commissioned in December that year, becoming the world’s largest offshore wind farm at completion.

Built as part of the multi-phase Hornsea development zone, the scheme includes extensive offshore works, inter-array cabling and a long export cable route making landfall at Horseshoe Point before connecting into the onshore substation at Killingholme. Overall, Hornsea One delivers around 4 TWh of electricity annually, supporting millions of homes and forming a core part of the UK’s offshore wind build-out.

Hornsea One sits within a broader plan to develop up to 6 GW of capacity across the Hornsea zone. Later phases—Hornsea Two, Three and the now-cancelled Hornsea Four—continue to expand the world-leading cluster, extending the project west, east and north across one of the UK’s most productive offshore wind areas.