In the four corners of the planet, wind farms are multiplying in the agricultural countryside and the seas, but attempts to install these turbines in urbanized areas, on the roofs of buildings, have almost always ended in failure. The presence of buildings and other obstacles such as trees makes the wind unstable and creates turbulence in the air. Which, in turn, cause noise pollution and vibrations in the masts and blades of these machines, thus having their lifespan and profitability. Should we therefore abandon all hope of harnessing wind energy in cities?
The French start-up Wind my roof founded in 2018 by two bridge engineers, Antoine Brichot and Yanis Maacha tries his luck in turn and takes up the challenge. The project was born in 2016, during a course in fluid mechanics at theSchool of Bridges. The two students observed there the behavior of the wind which, in the city, collides with the buildings, goes up along their facade and passes, while accelerating, above the edge of the roof (which the architects call “acroterion”) . It is therefore at this place that it must be exploited, concluded the two future engineers.
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Neither mast nor blade
But unlike “field” wind turbines, “city” wind turbines developed by Wind my roof composing neither mast nor blades. The two friends have designed metal boxes called wind box which contains a ducted turbine, with horizontal axis, of 1500 W and are exceeded by two photovoltaic panels totaling 600 Wp.
These hybrid modules are therefore based on the complementarity of technologies by exploiting the strength of urban air currents, but also solar energy. They occupy 4 m2 at the edge of the roof for a weight of 350 kg. Placed facing the prevailing winds on the acroterion of the roofs, they can produce annually – according to Wind my Roof – up to 2,000 kWh of wind energy and up to 800 kWh of photovoltaics, i.e. a total of 2800 kWh/ year.
In addition, electrical components such as inverters and batteries are pooled to reduce installation costs. The company further specifies that the WindBoxes can withstand gales up to 180 km/h and temperatures down to -15°C. 92% made in Francethey are “low carbon” products with emissions estimated at 25 grams of CO₂/kWh over a lifespan of 20 years.
Supported by an impressive list of organizations such as the Ministry of Ecological Transition, the Île de France Region, Ademe, the Solar Impulse Foundation, BPIFrance and even Vinci Energies, the young company – which now has seven employees – generated a fundraising of €700,000. A financial windfall that enabled him to install and test a first prototype on a building in La Défense. ” We have international objectives, and ambitions, particularly in Germany, because energy there is still carbon-intensive and the challenges there are multiple for a startup like WIND my ROOF. explains Yanis Maacha, one of the co-founders.
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First commercial installation on a building in Rouen
Associated to Rouen Housing, the startup finalized a few days ago a first installation of 8 WindBoxes on a building in the city. ” We are experimenting with WIND my ROOF the self-production of renewable energy on the roof of the Capricorne building located in the Hauts de Rouen. This project is good for the environment and for the purchasing power of households, especially in the context of soaring energy prices. We fight for the socio-ecological transition, in actions, and position our territory as a pioneer in terms of innovation declared on this occasion Nicolas Mayer-Rossignol, Mayor of Rouen, President of the Rouen Normandy Metropolis and of Rouen Habitat.
The building has 84 apartments on 10 floors. It was chosen for its characteristics which combine the ideal criteria for this type of installation: exposure to winds, height and reduced urban density.
The investment made by Rouen Habitat should make it possible to reduce the charges for the inhabitants of the building. The 8 Windboxes will provide electricity for the common areas of the building, self-consumption with resale of the surplus. The annual production of green electricity should amount to an average of 14 MWh for 20 years.
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