How Paris Is Using the Seine to Try to Keep Cool in Scorching Heat

Paris is using the Seine to cool critical buildings as extreme heat strains its district cooling network, according to Bloomberg. Under the streets of the French capital, a 75-mile network of pipes circulates chilled water to offices, malls, and sites including the Louvre. Operator Fraicheur de Paris, part of Engie SA, says the system uses 50% less electricity than a standalone approach and cuts emissions by half. Managing director Marie Carlo said chilling plants run around the clock, but record temperatures and occasional power outages sometimes prevent water from reaching usual cold levels. This year’s heatwave arrived before July’s typical peak, forcing the Louvre and the Eiffel Tower to close earlier, while transport disruptions and school shutdowns occurred across Europe. Carlo framed district cooling as increasingly vital amid climate change and cited past summer fatalities exceeding 60,000 in 2022 and about 47,000 in 2023. The process can chill water to as low as 4°C (39.2°F) and relies on refrigerants in a loop system; Paris’s rollout began on a small scale in the 1970s and expanded in the 1990s, with 14 chilling plants and ice tanks. Similar systems exist in Zurich, Singapore, and Chicago.