Paris expands Seine‑based district cooling network to serve 3,000 buildings

Paris is planning to triple the size of its district cooling system that uses cold water from the Seine to provide air‑conditioning for buildings. The network, known as Fraîcheur de Paris, currently supplies cooling to landmarks such as the Louvre and the Grand Palais and will be extended to more than 3,000 sites across all arrondissements by 2042. The system circulates cold river water through underground pipes, exchanges heat with building‑internal water via a heat‑exchanger, and returns the warmed river water without direct contact. The 20‑year contract, worth €2.4 billion, is jointly held by RATP and Engie, while the city retains ownership. Advocates say the approach reduces electricity demand and limits the heat‑island effect caused by millions of individual air‑conditioners, offering higher energy and environmental performance.

The expansion targets hospitals, schools, day‑care centres and retirement homes, aiming to lower overall cooling electricity consumption and mitigate urban heat. Monitoring so far shows temperature changes remain within ecological limits for the river, and the model is being observed by other cities considering similar water‑based district cooling solutions.