Building on the successful experience of its demonstrator Hywind Demo launched in 2009, the Norwegian company Statoil started in 2015 the world’s largest floating offshore wind park project, Hywind, to be installed, in north-eastern Scotland and 25 km off Peterhead,

Characteristic

  • Climatic conditions: strong and regular winds
  • Depth of water: 95 to 129 m (which did not allow the installation of offshore wind turbines)
  • Wind farm area: 4 km2
  • Height: 258 meters (foundation included), 80 meters immersed. The turbine towers will be 83 meters high with a diameter from 4.2 to 7.5 metres at the top and with a weight of 620 tons each
  • Weight of the submerged steel structure under the floats: 2000 tons
  • Anchors: attached to the seabed by a system of three-points mooring spread and a suction anchoring system
  • Foundations:  SPAR-type foundations, 3,500 tons each, 91 meters long and 14,8 m in diameter
  • Electrical architecture: wind turbines linked together by a network of cables, and also connected to the shore by an electric cable
  • Storage: 1MWh lithium battery
  • Cumulative power: 30 MW (5 wind turbines of 6MW each)
  • Expected output: 135 GWh per year, equivalent to the electricity requirements of 20,000 British households

For this project, Statoil received approval from the Scottish Government in November 2015. The investment for this project was € 214 million, representing a 60-70% cost reduction per MW compared to the Statoil demonstration park in Norway, Hywind Demo, launched in 2009.

Siemens supplied the  five SWT-6.0-154 direct drive offshore wind turbines. Nexans was responsible for the provision of static and dynamic cabling for a contract of approximately € 10.2 million. Nexans has also delegated to the Bardot Group the supply of buoyancy modules for electric cables. Navantia-Windar was in charge of the fabrication of the floating foundations. Finally, Navacel was awarded the contract for the construction of the five towers supporting the turbines.

Timeline

In March 2016, Navantia built the first block of the first floating foundation. The assembly of the five foundations was finalized in January 2017 at its production plant in Fene, Spain.

The two first foundations arrived in May 2017 at the project’s assembly base in Stord, Norway.

Credit: Olaf Nagelhus Woldcam/Statoil

In June 2017, the assembly of the five turbines started in Stord, waiting to be sent to Scotland after a series of tests.

Credit: Arne Reidar Mortensen/Statoil

In August 2017, the 5 wind turbines of the first floating wind farm Hywind have eventually been installed off Peterhead, in Scotland. The mooring system has been installed by NorSea Group (UK) Ltd., in association with Montrose Port Authority.

In September 2017, all the cables were installed. Statoil is currently conducting the final testing of the 5 wind turbines in Hywind Park before there commissioning planned for October 2017.

In October 2017, Hywind has started powering the Scottish grid.

Credit: Jan Arne Wold _ Woldcam / Statoil

Photo credit: Statoil

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