Paris Expands Seine River Cooling System

Paris is expanding its urban cooling network, which uses water from the Seine River to cool thousands of buildings, aiming to reduce energy consumption. For three decades, the city has utilized this centralized system as an alternative to individual air conditioning units that release heat into the streets and exacerbate urban warming.

The Fraîcheur de Paris system operates through 120 kilometers of underground pipes. Cool water drawn from the Seine flows alongside a pipe carrying warm water back from connected buildings. A heat exchanger transfers temperature between the two circuits without mixing the fluids.

Paris plans to triple the system’s reach by 2042, connecting over 3,000 buildings, prioritizing hospitals, schools, and care facilities. A 20-year contract, renewed in 2022 and valued at €2.4 billion, manages the network jointly by RATP and Engie, with the city of Paris owning the infrastructure. Other cities like Stockholm and Toronto have adopted similar systems, adapting them to local water sources.