an offshore wind farm works
Offshore wind power, kézako?
In the marine renewable energies sheet , you were able to understand the specificities of these energies. By 2030, France will have to produce 40% of electricity from renewable sources. Offshore wind power therefore fits perfectly with this objective.
What offshore wind power offers:
- Great productivity
At sea, winds are stronger and more regular than on land, so offshore wind turbines can be larger and more durable than those on land, creating more electricity.
- A competitive and low-polluting technology
Offshore wind emits little CO2.
- Significant potential
France has large and numerous maritime areas, which is therefore ideal for renewable energies, such as offshore wind power.
- Job creation
To build an offshore wind farm, you need engineers, technicians and specialized workers.
How does an offshore wind farm work?
To discover all the stages of operation of an offshore wind farm, watch the video below:
Wind turbines located at sea are called offshore wind turbines. For the Saint-Brieuc wind farm, they run and produce around 90% of the time. Each wind turbine has an electrical power of 8 Megawatts.
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- The blades drive a generator
Thanks to more regular sea winds, offshore wind turbines produce more than land wind turbines. The blades then drive the generator, which produces electricity.
- Electricity travels via a network of underwater cables
The wind turbines are connected by a network of cables to the electrical substation, which transforms the electricity arriving there into 66 kV to inject it into the terrestrial network at 225 kV.
How to build and connect an offshore wind farm?
- The construction
- We manufacture the elements that make up wind turbines
- We adapt port equipment to the needs of the project
- We transport the elements of wind turbines at sea
- Wind turbines are assembled at sea
- The connection
- We install the electrical station at sea
- We install the electrical cables at sea then to land
- We connect the elements to allow electricity to reach your home
The example of the Saint-Brieuc offshore wind farm:
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What does the Saint-Brieuc offshore wind farm look like?
Off the bay of Saint-Brieuc, the offshore wind farm is spread over an area of 75 km2, with the nearest wind turbine located 16.3 km from the Breton coast.
The park has 62 wind turbines, arranged in 7 lines of 3 to 14 wind turbines. The space between each line is approximately 1,300 meters and within these lines, the space between the wind turbines is approximately 1,000 meters, this is called the inter-turbine space.
The expected energy will amount to 1,850 Gigawatt hours, the equivalent of the electricity consumption of 835,000 inhabitants, heating included. This represents almost 9% of Brittany's total electricity consumption.
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The wind turbines are fixed on jacket-type foundations , made up of a metal trellis fixed to the seabed by 3 piles.
The electrical substation is located in the center of the wind farm, aligned with the turbines in the fourth row.
Who is Ailes Marines ?
Ailes Marines is a company owned by Iberdrola, a Spanish group operating in the energy sector. Ailes Marines is the name of the company created by Iberdrola, which is in charge of developing, building and operating the offshore wind farm in the Bay of Saint-Brieuc.
To carry out this project, Ailes Marines relies on a multinational project team of more than 100 people, around fifty of whom are based in France.
What to remember?
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Are you ready for the quiz?
Are you ready for the quiz?
Quiz: How an offshore wind farm works
What to remember?
Rotor : Moving part of a rotating mechanism.
Hub: Part fixed to the center of the rotor, which allows the latter to keep an axis thanks to its own fixing on the dial, allowing it to transmit rotation.
Landing junction: Connection point between submarine cables and underground cables.
Jacket-type foundations: These are metal structures on which offshore wind turbines rest. They are fixed to the seabed using 3 piles.
Maritime areas: Expanses of salt water in free and natural communication.
CO2: Carbon dioxide is a colorless and odorless gas. Its molecule is made up of one carbon atom and two oxygen atoms. The role of this gas is important in the greenhouse effect, because it keeps the Earth warm, but if its quantity is too great it can then cause global warming.