Stefan Grosjean about his encounter with Jérôme Michaud-Larivière, founder of the 'arbre à vent'
Jules Verne famously remarked that „everything that is beautiful and great in the world is the product of an outrageous hope.“
„You know when it's wind still in the city but you can still hear the leaves of the trees rustle? It was this paradox that I was trying to solve - why is it that we can't harvest these breezes, which are all around us?“
„It’s part of a wider problem. As a civilization, we use about 17 terawatts of energy per year. Wind generates about 800 terawatts annually around the world that can potentially be harvested – more than 20 times the amount of energy that we need. So there’s a huge disproportion between the renewable energy that is available and the way we generate and consume electricity. That fact should motivate us to find other ways of harvesting energy around us.“
Data show that Michaud-Larivière has a point. In his home country France, for instance, only about 3.1 per cent of energy is currently generated in wind farms.
It got Michaud-Larivière thinking about what he would need to catch those turbulent city breezes, and to package them in a form that would inspire consumers, architects and policy makers about the prospect of generating electricity close to the point of consumption.
From the first time I saw the Arbre à Vent, it struck me as a brillant idea. Consumers can’t build big wind turbines in their backyard, but the Arbre à Vent allows them to place a wind tree very close to their home. It fits with our vision at Smappee of empowering consumers to take responsibility for the renewable energy revolution.
„We started working on a leaf-shaped turbine that would start generating electricity at about half the wind speed that a bigger wind turbine needs. The aeroleafs, as we call them, are developed to catch micro-turbulence. They start producing at wind speeds of about 2 m/s, versus 4 m/s for traditional consumer wind turbines. Also, they don’t need a constant wind speed or direction, which makes them very useful in an urban context.“
The current generation of the Arbre à Vent generates about 2500 KWH per year, about a third of the average yearly consumption of a French household.
„It’s not a huge output as yet. But it is generated right at your doorstep, and it will produce energy right away, without the extra costs of installation that are sometimes forgotten, and which can be considerable.“
Also, placing a wind turbine at your front door or your backyard avoids the loss of energy that’s associated with energy transportation. It’s a dirty secret that energy grids lose between 5 and 10 percent of the generated power on the way from the power plant to your wall socket.
The main hurdles for Arbre à Vent today are to get performance up and the cost down. In fact, Michaud-Larivière admits that the current generation of Arbre à Vent is as much an educational project as an economic way of generating electricity.
„In some conditions, the Arbre can generate electricity in a much more economic way than other systems. To be honest, in most conditions today, it won’t. However, bear in mind that today we’re not benefiting from any economies of scale yet, and also, there is still room to increase the efficiency of the aeroleafs from about 23 percent to 28 percent.“
After making its début at the Paris climate talks last year, there are some 30 Arbres à Vent sold in Europe – of which 8 are currently installed in Switzerland, France and Belgium.
„Our clients are mostly people who are involved in sustainability – architects, designers, product developers, but also cities who want to showcase local, non-invasive energy production. Our clients know that the tree is more expensive than the gains it will bring – but they’re the kind of clients who want to bear witness to the energy transition, to educate people. As a planet, we cannot wait for the transition to happen. We need to make it happen.“
„Once we go into mass production, I think it should be possible to reach a pay back period of about eight years without subsidies. We’re working on that - we think we might get there by covering the trees in photovoltaic cells, for instance. My ultimate dream is to get the Arbre à Vent to a human scale – a size that would allow us to sell it at the likes of Home Depot and Leroy Merlin, where you could buy it and plant it at your front door.“
More about Arbre à Vent: http://www.newwind.fr/en/
Stefan Grosjean (@stfngrsjn) is an advocate for renewable energy and energy efficiency and is the founder and CEO of Smappee (www.smappee.com), the world’s smartest home energy monitor
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