In the suburbs of northeastern Paris, there’s a giant terracotta-colored warehouse with a labyrinth of windowless corridors. A deafening hum emanates from behind rows of anonymous gray doors, and disposable earphones are available under white delicate bars to shield passersby from the noise.
Here’s the incredible inside of one of France’s newest data centers, completed earlier this year and currently used to heat a novel Olympic Aquatics Center—seen from the roof of a data center. When American swimming star Katie Ledecky won her ninth Olympic gold medal last week, she did so by racing through water heated, at least in part, by data center machines.
Known as PA10, the clamorous site belongs to US data centre company Equinix – the humming sound is the company’s cooling system trying to chilly down its customers’ computer servers. “PA10 is specifically designed for high-density racks,” says the site’s data centre engineer Imane Erraji, pointing to a tower of servers capable of training artificial intelligence.
For the past month, the data center has been converting warm air into water, which is then sent to a local energy system run by a French utility company Engie. Once at full capacity, Equinix expects to export 6.6 megawatts of thermal heat from the building—the equivalent of more than 1,000 homes.
As forecasts suggest, artificial intelligence will soon turbocharged the amount of electricity that data centers need — Equinix predicts that energy exploit per rack could augment by as much as 400 percent — the PA10 reflects a European phenomenon in which officials are seeking to mitigate the environmental impact of the coming AI-related energy crisis and transform data centers into part of the infrastructure that keeps cities hot.
Erraji describes the project as a “win-win” for both Equinix and the local suburb of Seine-Saint-Denis. Equinix can remove heat from the building, so its cooling equipment doesn’t have to work as difficult, he explains, while the city gets a budget-friendly source of locally produced heat. After the project received 2 million euros ($2.1 million) investment from the city of Paris, Equinix has committed to providing free energy for 15 years. In June, the mayor of Seine-Saint-Denis, Mathieu Hanotin, also drew attention to the environmental benefits, saying that using the data centre as an energy source will save the region 1,800 tonnes of CO2 emissions a year.
However, according to the International Energy Agency (IEA), France has a “very low-carbon energy mix”, 62 percent electricity generated by nuclear power plants. And critics say the proliferation of heat-reuse projects distracts from the real problem: the amount of land, water and electricity used by data centers. “When data centers already exist, of course it’s better to reuse the heat than to do nothing,” says Anne-Laure Ligozat, a professor of computer science at France’s National School of Computer Science for Industry and Business (ENSIIE). “But the problem is the number of data centers and their energy consumption.” She adds that having a basic electric heating system without a data center would have a smaller environmental impact.