Floating wind power
A future pillar of the energy transition
Floating wind turbines offer huge potential to complement offshore wind farms..
What is floating wind power?
There are 2 types of offshore wind power: bottom-fixed and floating.
Bottom-fixed offshore wind
With bottom-fixed wind turbines, the turbines rest on a foundation fixed to the seabed. The foundation is usually a steel pile weighing up to 2,000 tonnes and penetrating 30 metres into the ground. Where the sediment is thiner, the foundation may be a steel mesh called a jacket.
Floating offshore wind
With floating offshore wind turbines, the structure supporting the turbine does not rest on the seabed, but, as the name suggests, on a floating platform. These structures are made of steel or concrete. As with boats, the submerged volume of the foundation allows it to be held at the surface by Archimedes’ principle. To prevent the floating wind turbine from drifting, the whole structure is anchored to the seabed using anchor lines and anchors.
With fixed-bottom wind turbines, the turbines rest on a foundation fixed to the seabed. The foundation is usually a steel pile weighing up to 2,000 tonnes and penetrating 30 metres into the ground. Where the sediment is thinner, the foundation may be a steel mesh called a jacket.
With floating offshore wind turbines, the structure supporting the turbine does not rest on the seabed, but, as the name suggests, on a floating platform. These structures are made of steel or concrete. As with boats, the submerged volume of the foundation allows it to be held at the surface by Archimedes’ principle. To prevent the floating wind turbine from drifting, the whole structure is anchored to the seabed using anchor lines and anchors.
This is a mature and highly competitive technology. The electricity price for the latest projects to be awarded in France in 2023 is around €45/MWh.
The costs of this technology are following the same trajectory as those of fixed-bottom wind power, but are not yet benefiting from its experience and economies of scale. Reducing costs is therefore one of the major challenges for floating wind power.
60 m
Maximum depth
1991
First land-based wind farm was installed (Denmark)
> 300 m
Maximum depth
2009
First land-based wind farm was installed (Norway)
Fixed-bottom
Typically, the maximum depth for such installations is 50 m. The first land-based wind farm was installed in Denmark in 1991. This is a mature and highly competitive technology. The electricity price for the latest projects to be awarded in France in 2023 is around €45/MWh.
60 m
Maximum depth
1991
First land-based wind farm was installed (Danmark)
Floating offshore
The first floating wind turbine was installed in Norway in 2009, so the technology isn’t as mature as fixed-bottom wind power. The costs of this technology are following the same trajectory as those of fixed-bottom wind power, but are not yet benefiting from its experience and economies of scale. Reducing costs is therefore one of the major challenges for floating wind power.
> 300 m
Maximum depth
2009
First land-based wind farm was installed (Norway)
For greater energy independance
The future of offshore wind is floating
Fixed-bottom and floating wind turbines complement each other. Fixed-bottom wind power has led the way in exploiting shallow seas. Floating wind will be installed in water depths greater than 60 meters where 80% of the offshore wind resource is found.
A massive source of renewable energy
Floating wind power is capable of producing 50%* of France’s annual electricity consumption*, just using 2% of the available surface area (the Exclusive Economic Zone) in mainland France.
* 371,000 km² x 2% x 8 MW/km² x 8760 h x 45% of the time = 50% of 460 TWh, the electricity consumption in 2022
Better integration to power grids
As winds at sea are stronger and more constant than on land, floating wind turbines can produce energy more regularly than photovoltaic or onshore wind turbines.
Environmental protection
The carbon footprint compares favorably with other energy sources.
of CO₂ per kWh
Wind turbines
of CO₂ per kWh
Gas-fired plants
of CO₂ per kWh
Coal-fired plants
And many more advantages:
- The electricity produced by floating wind turbines does not generate direct polluting emissions.
- It takes just 14 months for a wind turbine to produce the energy needed to manufacture it.
- Wind turbines are currently 85% recyclable, as they are mainly made of steel. By 2027, commercial wind farms will be fitted with recyclable blades, achieving a recycling rate close to 100%.
- Wind turbines do not generate waste heat (conventional thermal and nuclear power stations release 2 watts of heat for every watt of electricity produced).
Social acceptability
Reduced visual impact
Commercial floating wind farms can be installed far from the coastline, as their installation is not limited by water depth, and the best wind resource is typically far from the shore.
Limited conflicts of use
Floating wind turbines can be installed offshore, where there are fewer leisure and fishing activities.
Entirely reversible
Once dismantled, the floating wind farms allow the site to return to its original state. Anchors, chains and electrical cables are easily brought to the surface and then to port by workboats.
A French Offshore Wind Observatory
An Offshore Wind Observatory was set up in 2022 in France. Its remit is to make the most of existing knowledge and to launch new programmes to acquire knowledge about the marine environment and the impact of offshore wind farms on this environment.
A new job-creating industry
An industry with a future
Many countries have set ambitious deployment targets for offshore wind power: 45 GW by 2050 in France (i.e. 2,000 wind turbines); 50 GW in the UK by 2030.
Factories in France
Offshore wind power has already led to the deployment of turbine factories in Saint-Nazaire and Le Havre, and blade factories in Cherbourg.
New jobs
The production of floats will generate intensive activity in port areas. At least 10,000 jobs* are expected to be created by the industry.
* According to ‘Macroeconomic benefits of floating wind in the UK’ – Crown Estate – ORE Catapult – September 2018
Our concept
A solution designed for floating wind turbines.
Our achievements
See the progress of our projects.