Production, navigation, safety… How is France’s first offshore wind farm doing?

It brings together 80 wind turbines installed in the Atlantic Ocean, about 12 km from the coast. Off La Baule and Le Croisic (Loire-Atlantique), the Saint-Nazaire wind farm was fully commissioned on November 23. The site was particularly awaited since its delivery was several years late and it was, above all, the very first in France. It should not remain so for long since three others are currently under construction (Saint-Brieuc, Fécamp, Courseulles-sur-mer). Update on the first six months of activity.

Production “a little above” forecasts

It is the EDF group which is responsible for operating the wind turbines of the Saint-Nazaire park, which officially has a power of 480 MW, the equivalent of 20% of the annual electricity consumption of the Loire department. -Atlantic. What is it really for six months? “Production has not experienced any incident and is completely in line with forecasts”, says Marc Chiron, Deputy Director of Offshore Operations at EDF Renewables. On average, just over 160 GWh have thus been injected into the network, the equivalent of the consumption of approximately 700,000 inhabitants. A peak of 195 GWh was even reached in March. Given the weather and maintenance hazards, wind turbines do not run 24 hours a day but rather “80 to 90%” of the time, according to EDF. And when they turn, they do not develop the same power. “It is normal that there are variations in production. What the wind studies carried out tell us is that, over one year, the actual production should correspond to 40% of the site’s maximum power. For the moment, we are in the nails, we are even a little above. This calculation, called the load factor, is around 25% for onshore wind.

Navigation authorized but very supervised

Huge (78 km2 in total), the Saint-Nazaire wind farm can be crossed by boats, whether fishing, goods or tourism. But navigation is strictly regulated. A new decree of the maritime prefect moreover, has just been adopted before the summer season. This prohibits any vessel with a length of at least 25 meters. It is also forbidden to approach within 50 meters of a wind turbine, knowing that they are separated by one kilometer each, and to approach within 200 m of the electrical substation, a sort of transformer station. of the site. The speed is limited to 12 knots (22 km/h), the activation of an automatic identification system (AIS) is compulsory in the event of poor visibility, anchoring is not permitted, as is swimming. Scuba diving, appreciated because of the rocky bottoms of the sector, remains very supervised. “We are convinced that the park, which is part of the public domain, must remain accessible. For the moment the navigation is very moderate. But we suspect that it will increase with the good weather. It is therefore important to remember the rules. Are we too permissive or not enough? It will be necessary to adjust after several months”, estimates Jean-Michel Chevalier, assistant to the maritime prefect of the Atlantic.

Located 12 km from the coast, there are 80 wind turbines in the Saint-Nazaire wind farm. – F.Brenon / 20Minutes

Safety taken very seriously

Given its importance and vulnerability, the wind farm is constantly monitored from the EDF base in La Turballe, on the coast. Maintenance boats are regularly on site, especially in the summer. Cameras and radio equipment are also positioned on the wind turbines and the substation. Pranksters wanting to moor to the masts or activists wanting to climb it would “not go unnoticed” assure the authorities. Violations are tortious and will be prosecuted in maritime court, they add. “No incident has been observed, indicates the deputy to the maritime prefect of the Atlantic. The field may seem close to the coast but, in reality, 12 kilometers is very far for yachtsmen. You also need an offshore license to navigate there. In the event of an accident, rescue is coordinated by the regional operational center for surveillance and rescue (Cross). With “specific training” and “exercises” for helicopter pilots given the height (180 m at the tip of the blade) and the danger of wind turbines.

The impact on wildlife, too early to draw conclusions

The subject of the impact on marine fauna is closely watched by environmental associations. If the works have indeed generated a degradation of the seabed and nuisances for wildlife, EDF wants to be reassuring. “The initial state of the environment is very well known, reports Marc Chiron. A regular and precise follow-up of the evolution is set up with independent experts, in particular by means of robots and divers. It is too early to conclude on the environmental impact but we are already witnessing a recolonization by certain species attracted by the accumulation of organisms that attach themselves to the foundations. It’s the reef effect, like on wrecks. The transparency of the water, disturbed by the site’s drilling, has returned to normal. Groups of dolphins of more than twenty individuals have been seen in the park. As for the 46 species of birds identified in the sector, they are also monitored. The risk of collision exists even if the majority of them fly up to 30 meters above sea level, ie below the blades of wind turbines.

The view, impressive at the foot, criticized on the coast

When sailing in the middle of the wind farm, the height of the installations is very impressive, especially when a ship cruising in the sector makes it possible to compare the dimensions. On the coast, the visibility of wind turbines is low or nil in the event of mist or bad weather. But when the sky is clear, as has been the case for several days, the view of the park on the horizon line is undeniable from the island of Noirmoutier (Vendée), to the south, to Belle-île (Morbihan ), North. A novelty that disappoints many locals, as well as tourism professionals. “The visual impact is still very strong. Significantly more than expected. Including at night with permanent lights. Our wild coast is no longer wild”, regrets Michèle Quellard (DvD), mayor of Le Croisic. “I think we’re already getting used to it, I don’t pay attention to it anymore”, nuance Camille, owner of a residence in La Turballe (Loire-Atlantique).

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