Offshore wind power

History and characteristics of an innovative energy source

Offshore wind power is a true emblem of the energy transition and has already won over many countries. The production of energy by offshore wind power is indeed very interesting depending on the geographical location of the farms. In France, it has a real potential, thanks to a vast and windy maritime landscape.

However, despite the popularity of this innovative source of energy production, many questions remain: how does an offshore park work? How many are there in the world? Which one was the first to be built?

Today we answer all these questions.

How does offshore wind power work?

Offshore wind turbines are elements installed off the land coast. They are connected to the electrical grid via a submarine cable.

From a technical point of view, they work in the same way as onshore wind turbines, except for one detail: their installation at sea allows a better use of the wind energy, thanks to a more powerful actuation of the blades.

During the first experiments of offshore wind energy, and in particular during the launch of the first commercial wind farm in 2002, by the energy provider Elsam (now Ørsted), the turbine models used were simply onshore wind turbines, placed at sea. However, the marine conditions led to numerous breakdowns and required a complete repair of the nacelles and blades in 2004. From then on, the manufacturers reviewed the materials to be used, leading to the current models.

But why put wind turbines at sea?

The advantage of the open sea is that the winds are much stronger and more regular than on land. This makes it possible to produce up to 60% more energy than for onshore wind turbines, in particular thanks to the size of the turbines. In fact , an offshore wind turbine is 2 to 3 times more powerful than an onshore wind turbine.

It is important to know that a wind turbine only starts to produce energy when the wind speed is above 10 km/h. For example, a wind farm with an average wind speed of 30 km/h is 8 times more productive than one with an average wind speed of 15 km/h.

Since wind speed increases with altitude, offshore wind turbines are generally very tall and have wide blades, because the more air surface area is mixed, the greater the power of the turbine. For example, the turbine models used for the Saint-Brieuc wind farm are 207 meters high: that's more than the Mont Saint-Michel, as shown in the graph opposite.

Finally, the production and installation costs of offshore wind turbines are higher than those of onshore wind turbines, but their efficiency is higher.

Offshore wind power in France

Since the launch of the first national call for tenders in 2011, offshore wind energy has been booming and has become one of the pillars of a society looking towards a "greener" future. The gigantic marine potential of France opens up large energy production capacities. According to the Cerema, France has the 2nd largest potential for offshore wind energy development in Europe.

In addition to having a considerable maritime space, our country also has many port areas, and a recognized maritime, energy and industrial know-how.

To date, the first offshore wind farm in France is the one in Saint-Nazaire (Loire-Atlantique), composed of 80 wind turbines that will produce the equivalent of 50% of the domestic electricity consumption of the Loire-Atlantique. It was commissioned on September 22, 2022. Those of Saint-Brieuc and Fécamp will follow in 2023.

In a context where it is becoming imperative to ensure a form of energy autonomy, the French government is moving to adopt certain measures. As such, the Prime Minister, Elisabeth Borne, and the Minister of Energy Transition, Agnès Pannier-Runacher, have announced the launch of working groups focused on the theme of energy sobriety. The objective of this project: to reduce our energy consumption by 10% in two years to guarantee our security of supply in the context of the war in Ukraine and, in the longer term, to get France off fossil fuels by 2050.


In a few facts...


Wind power represents the greatest potential for energy development in the marine environment in the coming decade.


France has the 2nd largest offshore wind energy deposit in Europe, after Great Britain.


Europe is the world's largest offshore wind market.


The first offshore wind farm was built in 1991 in Denmark

Offshore wind power in Europe and elsewhere

The European Union has acquired undeniable expertise in the field of renewable energy. Indeed, due to its geographical location, it has a vast maritime space, distributed between the Baltic Sea, the North Sea, the Mediterranean, the Black Sea and the Atlantic. As a result, countries such as the United Kingdom and Denmark have taken the path of offshore wind energy and have independently developed several offshore wind farms.

In terms of history, Denmark was the host of the very first offshore wind farm, which appeared in 1991, in Vindeby. It was a real achievement for the time, but today we could call it a miniature park, as the scale and quality of current projects have grown.

By 2050, the European Union aims to achieve its goal of carbon neutrality. To achieve this, renewable energy production capacity must of course continue to grow. In this respect, large-scale projects tend to keep this promise. This is the case, for example, of the Seagreen project,the largest offshore wind farm inScotland, which started on August 22, when the first of 114 turbines was commissioned. Located about 27 kilometers off the coast of Angus, the 1,075 megawatt (MW) wind farm (designed to power the equivalent of 1.6 million homes) will be the world's deepest fixed-foundation wind farm, with a water depth of 59 meters.) It is expected to be fully operational in the first half of 2023.

In addition to the many farms present in Europe, a few farms exist off the coast of the United States but also in Asia, notably in Taiwan where the Formosa 1 offshore wind farm was launched in 2019.


The field of possibilities

Nowadays, "low carbon" energies are quite topical and are added to the list of solutions to fight against global warming. The challenge of 100% renewable energy is launched to reduce health, social and environmental impacts.

Ailes Marines is committed to this formidable challenge by applying the following actions:

  • Capture and take advantage of the wind of the Saint-Brieuc bay.
  • Focus on research, innovations, developments and environmental analyses aimed at producing more respectful, responsible and sustainable energy.

  • Ensure the protection of our environment and biodiversity.