Nexans picked to supply cables for the world's first floating wind farm

The new contract for Nexans to service the Hywind Scotland Pilot Park wind farm is worth approximately €10.2 million. There are now a few large-scale floating solar PV farms across the world (including a new one just outside London), but this contract – for what is believed to be the world’s first floating wind farm - follows a successful demonstration facilitated by Nexans’ cables. This has been in operation in Norway since 2009.

Nexans will deliver cables to the site, located about 25km off the coast at Peterhead in Scotland. The average length per cable will be 29.84km, the transmission type will be MVAC and the nominal voltage will be 33kV.

The offshore cable systems will be manufactured, tested, sealed off and prepared for pull-in at Nexans’ specialised facility in Halden, Norway – then to be delivered in individual lengths ready manufactured for installation. Delivery is scheduled for the end of 2017.

The Hywind project, which will undergo an initial two-year testing period, will generate green energy to power roughly 20,000 homes, and may lead the way – it is thought - to developing larger floating wind farms in other areas after an initial two-year testing period. 

The wind farm’s technology

The pilot 30MW floating farm will be made up of five Siemens model SWT-6.0-154 wind turbine generators (WTG) that will be an impressive 178m high, connected through an inter-array cable network before feeding into a single export cable carrying energy back to land in Peterhead, where it will be distributed via the Peterhead Grange substation. 

The Siemens WTGs are of the synchronous direct-drive permanent magnet type, having power regulation via rotor blade pitch change with variable speed. The WTGs will be positioned approximately 720m to 1,600m apart, and the platform will be attached to the seabed by a three point mooring spread. The inter-array cables may need to be anchored at some locations.

Following the successful Norway demo, the project, assisted by Nexans, which is a Voltimum  partier organisation, will demonstrate technological improvements, installation and operation of multiple floating wind turbines, as well as examine the cost efficiency of the park configuration.

The mass of CO2 reduced annually by this floating wind turbine array is estimated to be 42,942 tonnes, while the SO2 (sulphur dioxide) reduction is expected to be around 1,000 tonnes.

Pioneering alternative offshore wind design

Dirk Steinbrink, Senior Executive Vice President High Voltage & Underwater Cable Business Group at Nexans said, “This project is a great example of Nexans pioneering alternative offshore wind design, extending the options for renewable energy generation. 

“The contract”, he continued, “establishes Nexans as leaders in offshore wind innovation by designing specialist cables for both the initial pilot project and the Hywind Pilot Park. We are proud to be able to support Statoil as it helps the Scottish government realise its commitment to 100% renewable energy by 2020.”