How do Parisians stay so cool? A little-known cooling system snakes below ground at a depth of up to 98 feet, pumping icy water through 55 miles of pipes. It chills the air in over 700 sites in Paris, France. It’s helped the city cope with the sweltering heat that has broken temperature records across Europe.
The system uses electricity from renewable sources. It’s the largest in Europe. It chugs around the clock. But its deafening noise can’t be heard above ground.
Paris City Hall now plans to triple the size of the network by 2042. That would make it the largest urban cooling system in the world. The piping currently brings down the heat in some of the city’s most famous sites, such as the Louvre and the Quai Branly Museum.
Fraicheur de Paris, the company that operates the system, touts its benefits for the entire French capital.
“If all (Parisian) buildings get equipped with autonomous installations (such as air conditioning), it will gradually create a very significant urban ‘heat island’ effect,” says employee Maggie Schelfhaut. That refers to the increased heat in cities due to less vegetation—which cools the air—and more urban infrastructure—which absorbs the Sun’s rays.
But Schelfhaut says that the pipe network could make the whole of Paris one degree Celsius (1.8° Fahrenheit) cooler. “One degree less in the city center is a lot,” she adds.
Three of the 10 high-tech cooling sites lie on the Seine river. So just how does it work? When the Seine’s water is cold enough, a machine captures it and uses it to chill the system’s water. Heat created in the process is sent back into the Seine where it is absorbed. The cold water is then pumped though the system’s pipes to its 730 clients where it chills the air.
Paris’ cooling sites use renewable energy sources such as wind turbines and solar panels. French officials see this energy independence as particularly important given the threat of Russia cutting off energy supplies to gain political leverage. European nations are rushing to find alternatives.
The world’s most visited museum, the Louvre, has benefited from the network since the 1990s. A cool building is important for keeping artwork in good condition.
The Louvre does not use air conditioning. Officials also say the cooling saves them much needed floor space in the former palace that is home to 550,000 artworks.
Laurent Le Guedart is the Louvre’s Heritage Director. He says that the system is a money-saver given the rising cost of energy linked to the Ukraine conflict.
“The energy bill of the Louvre is around 10 million euros per year in 2021. We are trying to control this bill as much as possible,” Le Guedart says.
(Maggie Schelfhaut, communication manager of Fraicheur de Paris, walks through one of the company’s underground cooling sites. AP/Lewis Joly)