At the top of their 91-meter mast, the 117-meter-diameter rotors turn at a steady speed, taking advantage of the Picardy wind to generate electrical energy. In the Le Quesnel wind farm, in the Somme, the nine wind turbines operated by Valeco each produce between 3 and 3.6 megawatt hours of renewable electricity per year, which is added to the production of the 160 parks in the department. , the richest in wind turbines in France. “90% of the renewable energies produced in Picardy come from wind power,” explains Véronique Pauly, regional director of Enedis in Picardy. The Somme is the most endowed department, followed by the Aisne, because there is a lot of agricultural land, wasteland, wind, and few classified sites here. »
A boon for the region, while the objectives to be achieved in terms of carbon-free electricity production are constantly increasing. Today, this represents about a quarter of French energy consumption. To achieve carbon neutrality in 2050, it is a question not only of reducing electricity consumption by 40%, but also of increasing the share of carbon-free electricity in total consumption to 55%. It is therefore at least 150 terawatt hours of new electricity that will have to be found, while total consumption today fluctuates around 460 TWh.
The challenge is daunting, but it does not scare Cédric Boissier, director of the “Acceleration of renewable energies” project at Enedis: “In 2022, we connected 3.8 gigawatt hours of renewables, with two thirds of photovoltaic and one third of wind power. In the first quarter of 2023, the rise continues, particularly in private photovoltaics. We have connected 50,000 installations in 2021, 98,000 in 2022, and by the middle of 2023 we have already connected 115,000 installations. This phenomenon of acceleration brings us closer to the long-term objectives. “Objectives which certainly seem accessible in terms of production, but which raise the question of connection.
Because it is not enough to produce electricity, it must then be injected into the network. This step requires specific, colossal infrastructures, and also represents a significant challenge. These infrastructures are what are called substations. These are installations where the electricity produced at very high voltage circulates at a lower voltage, to then be injected into the network. At the heart of this structure are huge transformers, 130 tons, responsible for maintaining proper voltage.
Source substations are connected to production sites such as wind turbines, near which there are delivery points, approximately 20 to 25 kilometers apart. “The customer makes a connection request, and we then study each characteristic of the files to choose the best place to connect them,” explains Romain Genibrel, electrical and connection engineer at Valeco.
This connection represents another sizeable challenge, which requires titanic construction sites. Along the entire length of the route, cables are buried, most of the time buried in furrows dug on the sides of the roads, in consultation with the communities. “We have a very strong relationship with local elected officials, since we are under a concession regime”, recalls Cédric Boissier. Mayors are consulted on all electrical development projects, including the route taken by connection cables.
But the main difficulty comes from global warming. Indeed, copper, a very conductive material and therefore popular in the industry directly linked to electricity, is also very sensitive to high temperatures. “Part of the connection has a mixed composition between copper and aluminum, and another part is entirely in copper”, details Romain Genibrel. “The temperatures are taken into account in the connection calculations,” says Alexandre Wettstein, construction manager for northern France at Valeco. The specialist also explains that the power is limited to avoid excessive heating of the copper.
Faced with the challenge of climate change, wind power is therefore seeking to play its card, and certain regions, such as Picardy, are at the forefront of these changes. Nevertheless, there is still a long way to go towards carbon neutrality, and very often the delays in setting up wind farms are long, counting in years.