New markets for offshore wind turbines are marine areas with greater depths. Since conventional foundation concepts only range down to 50 m, wind turbines are learning to swim. Siemens have been involved since 2009. Now the company has been awarded a contract for the largest floating wind farm to date: the company is to supply five direct-drive offshore wind turbines with an output of six megawatts each for the 30-megawatt project “Hywind Scotland” off Scotland’s north coast. The systems will be installed on floating substructures at depths of 90 to 120 m.
In 2009, the Norwegian company Statoil and Siemens successfully installed a 2.3 MW-turbine for the project “Hywind Demo”. The current, much larger, project impressively demonstrates how floating wind farm concepts could be realised for large-scale commercial projects in a cost-effective way and with manageable risks in future years. A ballast keel and anchor cables keep the floating foundations in a stable position and allow for an upright position of the wind turbines in water. From the end of 2017 onwards, the project Hywind Scotland will annually generate around 135 gigawatt-hours of electricity and thus provide approximately 20,000 households with clean energy. Due to their low weight, the direct-drive offshore wind turbines from Siemens are particularly suitable for floating foundations. Interesting installation sites are off the coast of Japan, Norway and in the west of the United States.
It is estimated that by 2030, around 3.4 gigawatts of power provided by floating wind turbines are feasible. For Siemens, this future has already begun – as both Hywind projects have shown. “Once again, we are very proud of having realised a floating wind project with Statoil, and having set innovative milestones in the production of offshore wind energy,” said Morten Rasmussen, Head of Technology at Siemen’s Wind Power and Renewables Division.