According to write The Guardian, the district cooling system began to take shape in the 1990s. Today, it covers about 120 kilometers of underground pipelines, which provide coolness to museums, hospitals, schools, office buildings, hotels and other public facilities. The network is already connected, in particular, to the Louvre, the Grand Palais, large business districts and a number of historic buildings.
Photo: Damien Meyer/AFP/Getty
The system works by exploiting the natural coolness of the river water. Cold water from the Seine circulates in a separate pipe next to the pipe that drains warm water from the city's buildings. Through a heat exchanger, heat is transferred from one system to the other without mixing the water. The cooled water is then returned to the buildings, and the water from the Seine is returned to the river, with only a slight increase in temperature.
The network is currently being developed by Fraîcheur de Paris, which was awarded the concession to operate the system in 2022 with the support of the city authorities. Over the next two decades, the network is planned to be expanded to all districts of the French capital and connect more than 3,000 buildings, including hospitals, schools, kindergartens, nursing homes and other critical infrastructure.
Workers work on the access ladder to the underground city cooling network. Photo: Christian Hartmann / Reuters
The company notes that not all buildings require the same level of cooling or can technically be connected to the grid. However, the main goal is to transform the system from an infrastructure focused mainly on large administrative buildings to a full-fledged city service.
Experts call this technology one of the most effective ways for cities to adapt to climate change. Unlike conventional air conditioners, which remove heat from buildings to the outside and further heat the urban environment, district cooling significantly reduces the urban heat island effect and consumes less electricity.
A map of the locations of the underground cooling system operated by Fraîcheur de Paris. Photo: Lewis Joly / AP
Although the system returns slightly warmer water to the Seine, numerous studies have not found any significant negative impact on the river's ecosystem. Temperature changes remain minor and within environmental standards.
Similar solutions are already being used in other cities around the world. Stockholm cools buildings with water from the Baltic Sea, and Toronto with water from Lake Ontario. At the same time, experts emphasize that each city requires an individual approach: the implementation of such projects depends on geographical conditions, building density and the availability of appropriate underground infrastructure.
Raphael Nayral, secretary general of Fraîcheur de Paris, inspects an underground municipal cooling power plant in Paris. Photo: Christian Hartmann / Reuters
One of the main challenges remains cost. The total amount of the 20-year contract for the development of the Fraîcheur de Paris network is 2,4 billion euros, which makes such projects economically feasible primarily for large cities with a high concentration of consumers.
We previously wrote that the Seine has once again become a place for swimming: Three public beaches opened in Paris.
Main photo – Rowan Simpson / Unsplash