In Paris, 110 kilometers of underground pipes combat the heat at the Louvre and other monuments.
As Paris suffers an intense heat wave , a little-known network of underground pipes is cooling the Louvre Museum and other historic monuments with water from the Seine River .
The Seine River. Photo: FinoYossen.
Since 1991 , river water has been cooling more than 800 buildings through a humble but efficient system that is still relatively little used around the world.
The City of Light has the largest urban cooling network in Europe: 110 kilometers of underground pipes , which reduce the use of energy-intensive air conditioning systems.
"It's like 'Batman'!" exclaims a passerby in the elegant and touristy eighth arrondissement of Paris, as a spiral staircase emerges from the ground leading to the underground cooling network.
The technology isn't new . The United Nations headquarters in New York has been using water from the East River for cooling since the 1950s.
But it takes a lot of planning and construction , so such efficient and sustainable cooling systems remain relatively uncommon.
The Pont Neuf over the Seine River in Paris. Clarín Archive
In Paris, however, the network has expanded considerably in recent years to cope with more intense and frequent heat waves. The first of the summer is expected this coming weekend.
The process works similarly to a district heating network, but in reverse: heat is transferred from the air to cold water, which is pumped through pipes to the city's buildings.
But unlike conventional air conditioning, it doesn't release hot air into the streets , according to Fraîcheur de Paris, which manages the Seine cooling network and others in Barcelona, Singapore and Dubai.
The Seine River keeps the Louvre cool.
The company, co-owned by French energy company Engie, says it also offers significant savings in electricity consumption , chemical use, and carbon dioxide emissions.
Heat waves could raise summer temperatures to 50°C by 2050 in Paris, says Raphaëlle Nayral, secretary general of Fraîcheur de Paris.
"On Monday, we broke our absolute record in terms of deployed power, with 235 megawatts," Nayral told AFP, who believes they could set a new record this Tuesday, as Paris could reach temperatures of 40°C.
"From 9 a.m., we were at the equivalent of a full day's demand last summer in the middle of the Olympic Games," he said.
Stairs leading to Climespace's underground cooling facility in Paris, Canada, in a November 14, 2011 photo © Eric Piermont / AFP/Archives
For Nayral, the city needs a more sustainable solution than air conditioning, with its associated heat and energy costs. "Otherwise, we'll make this city completely uninhabitable," he says.
Studies have shown that heavy use of air conditioning systems can increase heat in urban centers by around 0.5°C , a figure that increases as more units are installed.
This type of air conditioning also accounts for 7% of global greenhouse gas emissions , according to the UN. This is due in part to the energy use and the refrigerant gases that tend to escape.
In the Paris network, 12 stations pump chilled water from the Seine to 867 sites across the city , including the National Assembly building, where deputies debate laws.
Even in winter, the river can be useful for cooling server rooms and shopping malls.
At the Eighth District station, arranged over four floors up to 30 metres underground , river water is pumped through a series of black tanks and large green pipes with a shrill noise.
Pipes and pumps at the Climespace Canada plant in Paris, in this photo taken on November 14, 2011. (Eric Piermont) (Eric Piermont/AFP/AFP)
"It's a bit like the singing of the Seine," Nayral says with a smile, listening to the hum of the compressors.
The process is subject to numerous environmental regulations . To avoid damaging the Seine's ecosystem, water withdrawn for cooling cannot be returned to the river if there is a difference of more than 5°C between the two.
Other sites served in the French capital include department stores and offices, the rail network, concert halls, and the world's most famous museum, the Louvre.
A hospital has also been connected to the grid , and the cooling benefit is expected to be extended to nursing homes, schools, and daycare centers across the city.
The pipes and pumps of the Paris Canada cooling system, by Climespace, in a November 14, 2011 image © Eric Piermont / AFP/Archives
" By 2042, the network should more than double , with 245 kilometers of distribution (...) to provide new cool spaces when the city overheats," Nayral points out.
For individual homes, the wait could be longer, as extensive renovations are required to connect residential buildings to the grid.
Clarin
