Wind power plays an essential role in the energy transition to renewable energies. While fixed-bottom onshore and offshore wind turbines have seen significant growth in recent years, floating wind turbines are a new technological innovation enabling wind resources to be exploited in areas where conventional solutions are unsuitable. Floating wind turbines have the potential to revolutionize the wind energy industry by offering greater flexibility and accessibility to deep-sea wind sites.
How floating wind turbines work
Floating wind turbines are offshore wind turbine structures that are not fixed to the seabed, but rest on floats or buoys. They are held in position by anchoring and cable systems, which allow the structure to adapt to sea movements. The main floating technologies are semi-submersibles, spar-buoys and tensioned barges.
Fixed-bottom offshore wind turbines, on the other hand, are installed directly on rigid foundations. This difference enables floating wind turbines to be deployed in much deeper waters, where winds are stronger and more regular. Nevertheless, wind turbines are gigantic structures and floating them, especially in rough seas, can be extremely difficult.
However, floating wind turbines also face challenges. The initial cost of these structures is higher than that of fixed-bottom offshore wind turbines, due to their complexity and the materials required. What’s more, anchoring floating structures and connecting them to the power grid presents major technical and logistical challenges. Engineers must also consider the environmental impact of these structures, particularly on marine wildlife and local ecosystems.
Floating wind turbine projects
Several floating wind turbine projects have been launched around the world. Among the most notable are
- Hywind Scotland : Developed by Equinor and Masdar, Hywind Scotland is the world’s first commercial floating wind farm. Inaugurated in 2017, it comprises five wind turbines, each rated at 6 MW, installed 25 km off the Scottish coast. The turbines are anchored to spherical floats and connected to the seabed by cables.
- WindFloat Atlantic: Located off the coast of Portugal, this project, developed by a consortium led by EDP Renewables, Engie and Repsol, consists of three floating wind turbines, each rated at 8.4 MW. Inaugurated in 2020, WindFloat Atlantic uses Principle Power’s WindFloat technology, based on a semi-submersible platform.
- Kincardine Offshore Wind Farm: This floating wind farm is located around 15 km off the east coast of Scotland. Developed by Cobra Group and operational since 2020, the project comprises six floating wind turbines with a total capacity of 50 MW.
In Scotland, the world’s largest floating wind turbines were recently installed, as reported by Ouest-France. These wind turbines, 258 meters high and each with a capacity of 14 MW, demonstrate the technological advances in floating wind power and the potential of this technology for large-scale renewable energy production.
Prospects for innovation
To make floating wind turbines more viable, several areas of innovation are envisaged, such as improving float design and materials, optimizing anchoring systems and reducing maintenance costs through automation and robotics. In addition, the development of subsea power grids and energy storage solutions could enable better integration of floating wind turbines into national and regional energy systems.
What are the advantages and disadvantages of floating wind turbines?
The advantages of floating wind turbines include access to larger wind resources in the deep sea, far from coastal areas, thus reducing visual impacts and noise pollution. In addition, floating wind turbines reduce installation and maintenance costs, as they do not require complex and costly foundations.