A solar oven for green steel

Direction Saignelégier, at the French border. As we go deeper into the valley, we come across a small industrial area at the foot of the mountains. Here, nestled between the garage and the tennis club, is Panatere, a watch subcontractor who, in addition to making timepieces for a few major brands, has set out to make the national emblem of the watch industry more virtuous. On the agenda: waste collection, new sorting technologies, and metallurgical innovations. At the Panatere headquarters, 44 employees work every day to achieve a specific objective: to work for the environment without making any concessions on the quality of the finished product.

At the origin of this initiative, we find an anomaly in the Swiss watch industry, which consumes nearly 9,000 tons of steel every year. In manufacturing, precision is the order of the day. Each piece is finely machined, generating abundant metal scraps. Every year, 1,500 tons of steel are thus thrown away in the form of chips. According to figures from the Ministry of Ecological Transition, the production of one ton of this metal emits 1.8 tons of CO2, the equivalent of 9,000 km by car, and 900,000 by train. By wasting 1,500 tons of steel every year, the Swiss watch industry produces 2,700 tons of CO2 unnecessarily. The equivalent of a trip of 1.35 million kilometers by train, or the Earth-Moon distance... 4 times.

In Jura dialect, a panatère is a small wicker basket used to collect fruit. And it is in reference to this peasant icon that the Panatere company collects metal waste from nearby factories to give them a second life. And right in the heart of Watch Valley, there is plenty to do. “The idea is to produce quality steel, 100% recycled, without the addition of minerals, which has never been seen before” declares Raphaël Broye, founder of Panatere. “With our network of partners, we operate in a short circuit, like farmers.” Once their collection is complete, Panatere sorts the waste using a patented method, before sending it to small local foundries, from where new 100% recycled ingots come out. A concept that is as much about the short circuit as of the circular economy, which, applied to Swiss watchmaking, responds to the problems of waste and shortage of components.

While this collaboration with local steel mills lasted a while, it was never optimal. The founder of Panatere says: “Our waste was cumbersome for metallurgists, who were used to working in large quantities, so we had to find another system.” The specifications are clear: a solution is needed that is more agile, always local, and more ecological. “For a while, we thought about a photovoltaic system,” he says, “But due to lack of space, we were interested in solar ovens.”

Their main inspiration is the oven in Odeillo, in the Eastern Pyrenees. This giant, 60 meters wide and 50 meters high, belongs to the CNRS and is capable of producing a heat of 3500 degrees. “This is well beyond the melting point of most metals.” declares Raphaël Broye. Numerous tests have been carried out in partnership with the CNRS, revealing the great potential of this method: “We obtain better quality steel, with a carbon balance divided by 165”. Quickly, Panatere decided to build its own solar oven “the first for industrial use” affirms its founder. After a brief study carried out with MétéoSuisse, it was decided that the oven would be built in the town of La Chaux-de-Fonds, the second sunniest city in French-speaking Switzerland, 25 kilometers from the Panatere headquarters.

In spring 2023, the solar metal processing center will finally be built. Ultimately, it should produce 200 tons of recycled steel per year. Through the collection of industrial waste and the development of new metallurgical technologies, Panatere wishes to provide a sustainable, profitable and ecological solution to the traditional production of raw materials. By developing a system based on the circular economy and short circuits, Panatere is becoming the reflection of a watch industry eager to carry out its revolution on time.

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