Paris will triple the length of underground pipes that deliver chilled Seine water under the Fraîcheur de Paris district cooling network. The system, conceived in the 1990s by a subsidiary of Engie, runs through six interconnected subterranean plants that pump cold river water through one pipe with a parallel return pipe carrying warm water to cool large buildings such as the Louvre. The network already reaches about 900 buildings and the city aims to expand service to roughly 3,000 buildings by 2042. City officials say centralizing cooling reduces reliance on thousands of individual air-conditioning units, cuts refrigerant emissions by about 90 percent, and helps stabilize the power grid. Supporters call it one of the world’s largest district cooling systems and a lower-carbon alternative as Cooling Degree Days in Paris have doubled over the last 40 years. Critics warn that the Seine’s low summer flows, pollution and nutrient loading risk algae blooms, eutrophication and harm to fish, and note that high river temperatures have already caused operational problems for French nuclear reactors. By tripling pipe capacity, Paris expects to extend centralized cooling into more public and cultural buildings, easing peak electricity loads and stabilizing the grid during heatwaves.
