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Retro Tech: When the past inspires innovation for a sustainable future

Rechargeable alkaline batteries, hydrogen powered cars, solar printers… Will these innovations revolutionize our daily lives? These ideas and principles are hardly new – in fact, some of them were invented more than a hundred years ago! Innovating to enhance our future also means exploring our past and the ingenuity of engineers, inventors and architects of previous centuries.

A public service laboratory harvesting knowledge from forgotten innovations

Cédric Carles’ enthusiasm is catching! The founder and director of Atelier 21, a designer by trade, used a range of examples to illustrate the principles of retro tech during his round table discussion at the Hacking de l’Hôtel de Ville on March 6th in Paris : “When the past comes to the rescue of a sustainable future”. “The climate emergency – and its impact on buildings and temperature regulation - is what brings us together. The idea is to create a community based on our research, to offer workshops on how to cool buildings inspired by architects using ancient techniques, to share ideas and inspire social housing projects, real estate developers, etc.” One example is the White roof project in New York that repaints roofs using reflective colors to offset the albedo effect. A self-declared “public service laboratory”, Atelier 21 was born in Switzerland 15 years ago to “offer a methodological approach to innovating by exploring the past”, says Cédric Carles. In short, Atelier 21 is a think tank for ecological transition in France and in Switzerland, with contributions from many other countries. Its stated objective is to activate communities, to raise awareness and gather historical know-how on innovation, making it readily available to all. “We realized there was a lack of resource sharing between engineers and startups, between engineers and professors when it came to the question of innovation. The available resources are sparse, and we wanted to combine them into one research program, unearthing energy-saving patents and inventions”. Atelier 21 is a trans-media project that includes the creation of a roadshow exhibit, prototypes of newly-rediscovered patents, a historical museum of energy innovation, and a reference book :  Rétro-futur, une contre histoire des innovations énergétiques.

From the depths of history to prototyping

What exactly are these patents that resonate with us in an especially relevant way today? The solar printer prototype by Augustin Mouchot and Abel Pifre was first invented in France in the 19th century, but the patent was discovered by a team in Vancouver. The hydrogen-powered car that excites our imagination today was dreamed up by Jean-Luc Perrier in 1979. The Atelier 21 team is currently researching a prototype of this car; they intend to build a heritage collection for a new museum featuring the precursors of ecological transition. There’s also the ingenious invention of Denis Papin, who in 1682 envisioned a way to soften bones and cook all types of meat quickly and cheaply – the precursor of the ubiquitous pressure cooker popularized centuries later! Finally, the team has unearthed a patent that calls for recharging alkaline batteries. Developed in the 1980’s by an electro-chemist, the product was quickly taken off the market: “We’re starting to prototype it and innovate with testing, fab labs and teachers, who are making recharge cycles. Beyond the recharging tool, this project gives us valuable information on battery capacity that is never shared with consumers. We’re in the process of building a battery Yuka”, Cédric Carles enthusiastically declares.

Why are these innovations - flops when they were originally invented - now making a comeback and taking center stage? “The stakes are high and we must inspire today’s society. The paradigm has shifted, we now have new concerns. This explains why some patents weren’t prototyped when first created – when there was no climate emergency, and the low cost of petrol didn’t necessarily encourage energy-saving initiatives. Today, we believe these ideas are ripe for sharing once again”.

Adapting existing structures to the constraints of dense urban areas and climate change: the Air project

In France today, 300 000 building companies generate 40% of waste and CO2 emissions nationwide. On 25 July 2019, temperatures in Paris reached a record high of 42,7°C. The growing rate of pollution in Paris, exacerbated by climate change, is a vicious cycle: in 2018, 42 days of pollution rates surpassing authorized thresholds were recorded. Finally, “hot spots” in Paris are partially caused by urban density: “In the heart of Paris, it’s much hotter than in areas 8 kilometers away, where temperatures are 5 to 8 degrees lower. The phenomenon is also caused by the dense urban landscape of Paris; instead of rising, heat stagnates. We can’t rebuild the architecture of Paris, so how can we cool the air naturally?”, asked Lucille Leyer and Romain Brochard, architects and partners at Ylé architecture firm. They observe that “we have to build differently, to adapt to the city of tomorrow”. Ylé, which means raw materials in ancient Greek, was created a year and a half ago, through a project developed by the Pavillon de l’Arsenal and the City of Paris for the Faire 2019 contest. “We’re trying to create architecture with the resources we have around us, in our local environment, especially organically-sourced resources. We’re coming up with new ways to make intelligent use of existing materials”. The Air project aligns with this vision, analyzing ingenious methods used in warmer countries and adapting them to the architectural heritage of Paris. In the capital, architects identified 60 Haussmann-era buildings with environmentally under-exploited courtyards and chimneys. “Initially, the courtyards were built to give access to air and light, but that ventilation no longer works properly – they’re now used as waste storage areas. We want to revegetate courtyards by rolling out a landscaping program. Similarly, chimneys are the backbones of these buildings, but many are no longer in use due to strict urban regulations. They could be utilized to ventilate air upwards towards the rooftops through a wind tower model”.

Opening the windows of Montparnasse Tower: a challenge at the crossroads of architecture and engineering

Different times, different architectural concepts. Guillaume Meunier opened the public debate on Montparnasse Tower. The Deputy Director in charge of the environment for Elioth engineering workshop says, “I’m trying to prove that the idea of opening windows sometimes leads to complex solutions, and that retro tech lets us combine various approaches”. The Montparnasse Tower rehabilitation project focuses on a natural ventilation approach. The idea: to cool the building, outside air must be brought in to limit the use of air conditioning. “We’re in Paris, in a dense cityscape, in a tower where it’s not always possible to open the windows as the wind is extraordinarily strong on the upper floors. Yet 50% of the tower’s energy consumption is used for cooling systems.” The team believes opening the windows is vital to attaining energy efficiency. Their approach lies at the crossroads of architectural engineering, by staggering façades and installing compression-decompression microsystems. To test the new configuration, test models and protocols were used to demonstrate they could be implemented on a larger scale. “In the end, we created vertical wind tunnels using pressure to bring air into the conduits, and a blower at the foot of the building sending it back up to the office spaces.” The question of implementation hasn’t yet been resolved: use a low-tech mindset, whereby occupants open/close their own windows, or install an automatic system using a complex algorithm to gauge temperatures and open/close windows? But the resulting energy savings of up to 10% make it worth taking a closer look. “Wind towers are an exceptional example – they’ve never disappeared and are consistently used in developing countries where there’s a need for affordable natural cooling solutions. In contrast, the systems we’ve invented are sometimes ecological aberrations. The more heat waves we experience, the higher the temperatures, the more people will want air-conditioning – it’s a vicious circle. Public authorities may well forbid the use of air-conditioners, but if there are no credible alternatives people will circumvent the law. I’m already astounded by the number of illegal façade cooling units I see everywhere”, adds Jean-Louis Missika, Deputy Mayor of Paris in charge of architecture, urban planning, the Grand Paris project, and economic development and attractiveness.

 “I think it’s been demonstrated that retro tech offers a wealth of new opportunity. The history of technical progress is a history of missed opportunities, of choices made arbitrarily. When you examine the history of the birth of the automobile, you realize that we came very close to the electric car, and the arguments in favor of it were the same ones we hear today: it’s better adapted to urban environments than thermal vehicles. Sometimes it’s simply chance, or the technology isn’t yet ready, or industrial players influence governing bodies to push certain technological choices. And it’s true that earlier solutions were sometimes proven to be of little use, such as triple-glazed windows with water circulation. It’s clear that when fossil fuels were cheap and global warming wasn’t an issue, it wasn’t the best solution. Yet suddenly we’re realizing that in our current context, it might be a fantastic solution. So retro-innovation is very important, and I believe researchers and entrepreneurs should take a closer look at these questions”, concluded the Deputy Mayor.  



Interview de Cédric Carles, la rétro tech