Offshore wind news: innovative Keystone 'twisted jacket' foundation design successfully demonstrated at Hornsea

The demonstration is a significant step on the route to commercialising the structure for use with turbines. The project incorporates a comprehensive monitoring programme and will provide valuable insights into optimising the structure for fabrication and installation.

The 'twisted jacket' uses less steel than a conventional jacket and is easier to fabricate, using fewer components. Installation costs will also be lower because more units can be fitted onto an installation barge due to its small footprint.

The Offshore Wind Accelerator foundation competition was launched in 2009 to find cheaper foundations for 30-60m water depths and attracted 104 entries from all over the world. Over the last 18-months, the Carbon Trust and the eight OWA members: DONG Energy, E.ON, Mainstream Renewable Power, RWE, ScottishPower Renewables, SSE, Statkraft and Statoil have invested in the conceptual design and de-risking of four finalists, and undertaken a programme of work to assess the impact on the cost of energy of each design.

The foundation supports the first met mast to be installed for Round 3 and the data collected will inform the wind farm design and energy production estimates. The 4GW Hornsea zone is being developed by SMart Wind, the joint venture between Mainstream Renewable Power and Siemens Project Ventures.