Offshore wind turbines can be installed in one of two ways: either on a foundation permanently attached to the seabed (a 'fixed' installation) or on a floating base anchored to the seabed.

  • Offshore turbines harness the power of sea winds to generate energy in the form of electricity. © Adwen
  • The floating offshore wind turbine is a technology of the future, and offers the benefit of being able to operate in extremely windy deepwater areas far from the coast.

What is offshore wind power?

Offshore wind turbines harness the power of sea winds to generate carbon-free renewable energy. They work in exactly the same way as onshore generators; the only difference being that it is installed at sea and is either anchored to the seabed or mounted on a floating structure. Using masts much higher than those of onshore turbines, offshore wind generators can generate up to twice as much energy than their onshore counterparts, because they can rely on higher and more consistent wind speeds.

Last year, offshore wind farms achieved a new level of total generating capacity, with more than 4,000 MW worldwide. The majority of this growth came from two new projects; one in Germany (2,400 MW) and the other in China (500 MW). These two countries lead the industry alongside the UK, which still boasts the largest offshore wind generating capacity (5,400 MW of installed capacity at the end of 2015*)

Fixed offshore wind power projects run by ENGIE

  • In France: the projects at Le Tréport and the islands of Yeu and Noirmoutier
    With its projects off Dieppe and Le Tréport and the islands of Yeu and Noirmoutier, ENGIE is making a significant contribution to the development of a long-term offshore wind power industry in France. The consortium of ENGIE, EDP Renewables and Neoen Marine has been awarded the government contract to develop and install two offshore wind parks with combined power generating potential of 1,000 MW. The estimated generating capacity of these wind farms should therefore be sufficient to meet the energy needs of 1.6 million consumers. At the cutting edge of innovation, each of these wind farms will have 62 Adwen 8 MW wind turbines. ENGIE and its partners are implementing these projects in close cooperation with local stakeholders. To find out more and receive regular updates on these projects, visit the websites for the Dieppe and Le Tréport project and the project for the islands of Yeu and Noirmoutier.
  • The Mermaid project in the North Sea
    ENGIE Group company ENGIE Electrabel is working as part of the Otary consortium (65%) on the Mermaid project in the Belgian North Sea. This wind park was granted its first offshore permit on April 15 this year, and is expected to become a reality in 2020. Between 27 and 41 wind turbines will be installed here to deliver a total generating capacity of around 250 MW. The Mermaid project will generate enough electricity to meet the annual consumption needs of 286,000 Belgian households, reducing the country's CO2 emissions by 367,000 metric tons per year.
Floating wind turbines: key benefits and features

Floating wind turbines: generating power in the deep offshore

Like fixed offshore wind turbines, the floating wind turbine generates electricity by converting the mechanical energy of the wind. But its floating structure enables it to generate power a long way offshore in deep water where the sea winds are stronger and more consistent. Another benefit is its ease of installation, since there is no need to cast solid foundations or to use the kind of specialist construction vessels needed for fixed offshore wind turbines. At between 15 and 22 km from the coast, the visual and maritime impact of these windfarms is also relatively low.

Floating wind power technology may still be at the pilot plant stage, but this sector is of strategic importance for coastal regions in terms of jobs, industry and ecology. The technically exploitable potential of floating wind power in Europe is estimated at 600 GW, compared with 250 GW for fixed offshore wind power*.

Floating offshore wind power projects run by ENGIE

  • The WindFloat Atlantic project in Portugal
    ENGIE is already involved in floating offshore wind power development with the WindFloat Atlantic project off the north coast of Portugal in partnership with EDP Renewables, Mitsubishi Corp., Chiyoda Corp. and Repsol. Planned to enter service by the end of 2018, this pilot installation will use 3 or 4 generators to provide a total generating capacity of 25 MW, and will be built on semi-submersible foundations designed by Principle Power.
  • The expansion of the French offshore wind industry
    The Mediterranean coast of France is particularly well suited to the development of offshore renewables, which is why ADEME launched its Pilot Floating Wind Farm call for projects on August 5 last year. Its aim is to install pre-commercial wind farms in four clearly defined areas (three in Languedoc-Roussillon and one in Brittany).

    The consortium of ENGIE, EDP Renewables, Caisse des Dépôts and Eiffage submitted a joint project focusing on the area off Leucate on the Mediterranean coast; France's most promising offshore wind power resource. Their Golfe du Lion Floating Wind Power project is being designed in close consultation with local stakeholders, and will include between 3 and 6 wind turbines, each rated at 6 MW. They will be used in conjunction with an integrated semi-submersible floater from Eiffage Métal. Developed by Principle Power, the concept has been tested off the Portuguese coast since 2011. This solution is the most promising technology in today's market.

* IFP Energies nouvelles (in French only)

About ENGIE

ENGIE develops its businesses (power, natural gas, energy services) around a model based on responsible growth to take on the major challenges of energy’s transition to a low-carbon economy: access to sustainable energy, climate-change mitigation and adaptation, and the rational use of resources. The Group provides individuals, cities and businesses with highly efficient and innovative solutions largely based on its expertise in four key sectors: renewable energy, energy efficiency, liquefied natural gas and digital technology. ENGIE employs 154,950 people worldwide and achieved revenues of €69.9 billion in 2015. The Group is listed on the Paris and Brussels stock exchanges (ENGI) and is represented in the main international indices: CAC 40, BEL 20, DJ Euro Stoxx 50, Euronext 100, FTSE Eurotop 100, MSCI Europe, DJSI World, DJSI Europe and Euronext Vigeo (Eurozone 120, Europe 120 and France 20).

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