The Mona Lisa may maintain her famously mysterious smile as she benefits from one of Paris’ best-kept secrets: an underground cooling system that has helped the Louvre cope with the sweltering heat that has broken temperature records across Europe .
That lesser-known “urban freezing” network snakes beneath the feet of the snake at depths of up to 98 feet (30 m), pumping the icy water through a 55-mile (89 km) labyrinth pipe, which was used for 700 years. Sites used to cool more air
The system, which uses electricity generated from renewable sources, is one of the largest in Europe – and operates round the clock with rumbling noises that are completely inaudible above ground.
Paris City Hall has now signed an ambitious contract to triple the size of the network to 157 miles (252 km) by 2042, which would make it the largest urban cooling system in the world.
The new contract aims to help the city adapt and combat the threat of global warming. Many parts of Europe hit 40C (104F) in July.
The city is expanding its cooling network for hospitals, schools and metro stations over the next two decades.
It is unclear how much of the system will be operational by the time of the Paris Olympics in 2024, but it is possible that the system will be used at several Olympic venues.
Unknown to millions of tourists, piping currently cools the City of Light’s most emblematic landmarks, such as the Louvre and the Quai Branly Museum.
The scheme is operated by the joint venture company Frachur de Paris – 85pc is owned by state-run French energy company EDF and the rest by public transport operator RATP.
“If all (Paris) buildings become equipped with autonomous installations (such as air-conditioning), it will gradually create a very significant urban ‘heat island’ effect,” said Maggie Shelfhaut of the Frachur de Paris, of the rising heat. Referring to. Cities due to less vegetation, which is cooler, and more urban infrastructure, which absorbs the sun’s rays.
But she said the pipe network could cool Paris 1C (1.8F), if autonomous installations are put in place across the city.
“A degree less is a lot in the city center,” she said.
Three of the 10 high-tech cooling sites are located on the Seine River and are accessed by a retractable spiral staircase that’s barely visible from street level—something like Teenage Mutant Ninja Turtles’ Lair.
When the Seine water is cold enough, a machine captures it and uses it to cool the system water. The heat created as a by-product is sent back to the Seine, where it is absorbed. Chilled water is then pumped though the system’s pipes to its 730 Paris customers.
All cooling sites in Paris use renewable energy sources such as wind turbines and solar panels. Four new solar power sites that will be part of this network have also been earmarked for construction.
French officials see this energy independence as particularly important because Russia has cut off energy supplies to Europe.
The merits of using a cooling system that uses renewable energy to operate are already being realized by the sites that use them. The world’s most-visited museum, the Louvre, has benefited from the network since the 1990s – authorities are proud of its ecological, economic and art conservation benefits.
“This allows us to benefit from energy with a low carbon footprint available throughout the year,” said Laurent Le Guédart, the Louvre’s heritage director. “The uniqueness of the Louvre Museum is that it needs to use ice-cold water to properly preserve the artwork and control the humidity.”
The Louvre does not use air conditioning and officials say the cooling gives them much-needed floor space in the vast, yet cramped, former palace that is home to 550,000 artifacts.
It operates exclusively in the State Room of the Pavillon Denon where Leonardo da Vinci’s Mona Lisa resides.
“The Louvre’s energy bill is around €10m per year in 2021. We are trying to control this bill as much as possible, amidst obvious fluctuations and escalating energy costs,” said Mr. Le Guédart.