A small dark nugget-sized material made up of copper, lead and phosphate that acts as a superconductor shook the scientific community last week. Superconductors are special because they conduct an electrical current with zero resistance. The rub is that they currently only work at extreme temperatures: think −243.15 °C. This new discovery, LK-99, is reportedly a superconductor that works at room temperature. With the constraint of extreme temperature removed, the possibilities are seemingly endless. But as stock markets surged in response to the news and social media lost its sanity (what’s new?), the findings about a material that could one day facilitate hovertrains as the norm is now under the global microscope. So, let’s dive into a case study about what superconductors are already doing. Nexans, a Paris-based multinational in our Clean Energy & Technology fund (C5KG), has used superconductors in a number of projects. One is providing a new power supply to connect the Montparnasse station in Paris to the Vouillé substation using superconducting cables. A dozen conventional copper cables would have been needed to deliver the required power to the station, but this would have meant digging up the surrounding roads. Nexans solved the problem by using two superconducting cables, which only need small dimensions to operate efficiently, avoiding the need for disruptive roadworks. It’s the first-ever use of superconducting cables in France and will make the Montparnasse to Vouillé connection the first superconductor used in a railway grid on Earth. It’s not quite a levitating train at Montparnasse, but as James Clear says, “the aggregation of marginal gains is a powerful force.” More on this story FT, Times, Nexans.