In the northeastern suburbs of Paris sits a huge, terracotta-coloured warehouse with a labyrinth of windowless corridors, where a deafening roar emanates from behind rows of nameless grey doors and, beneath white strip lights, disposable earphones are provided to insulate passersby from the noise.
These are the magical insides of one of France’s newest data centers, completed earlier this year, and now being used to heat the new Olympic aquatics center, which can be seen from the data center’s roof. When US swimming star Katie Ledecky won her ninth Olympic gold medal last week, she did so by sprinting through water that was heated, at least in part, by machines in the data center.
The noisy facility, known as PA10, belongs to American datacenter company Equinix, and the whirring noise is the company’s cooling systems trying to keep clients’ computer servers cool. “PA10 is specially made for high-density racks,” says Imane Erraji, a datacenter engineer at the site, pointing to a tower of servers that can train AI.
For the past month, the data center has been turning hot air into water and sending it to a local energy system run by French utility Engie. At full capacity, Equinix expects the building will be able to pump 6.6 megawatts of heat out of the building, enough to power more than 1,000 homes.
With forecasts suggesting AI will cause a sharp increase in the amount of electricity data centers need (Equinix predicts power consumption per rack could increase by up to 400%), PA10 reflects a phenomenon in Europe, where authorities are trying to mitigate the environmental impact of a coming AI-driven energy crisis and turn data centers into part of the infrastructure that keeps cities warm.
Elazi describes the project as a “win-win” situation for both Equinix and the city of Seine-Saint-Denis. Equinix can pipe heat out of the buildings, reducing the strain on cooling equipment, he said, while the city gets a locally produced, cheap source of heat. The project has received 2 million euros ($2.1 million) in investment from the city of Paris, and Equinix has pledged to provide free energy for 15 years. In June, Seine-Saint-Denis’ mayor, Matthieu Anotan, also highlighted the environmental benefits, claiming that using the data center as an energy source could reduce the region’s annual carbon emissions by 1,800 tonnes.
But France’s electricity mix is ”very low carbon,” with 62% of its electricity coming from nuclear power, according to the International Energy Agency (IEA). Critics also say the rise in heat reuse projects is a distraction from the real issue: how much land, water and electricity data centers consume. “Obviously, if you already have data centers, reusing heat is better than doing nothing,” says Anne-Laure Rigozat, a computer science professor at the French National School of Industrial Management and Information Sciences (ENSIIE). “But the question is the number of data centers and their energy consumption.” Installing a basic electric heating system without data centers would have less of an environmental impact, she adds.
