Yet France has a “very low-carbon electricity mix”, according to the International Energy Agency (IEA), with 62 percent of its electricity generated by nuclear power. And critics say the proliferation of heat-reuse projects distracts from the real problem: the amount of land, water and electricity data centers consume. “When the data centers are already here, of course it’s better to reuse the heat than to do nothing,” says Anne-Laure Ligozat, 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.” There would be less impact on the environment if there was a basic electric heating system without a data center, she adds.
Recently, projects to capture and reuse heat to heat homes, offices or universities have sprung up across the region as data centers face increasing pressure to help the European Union meet ambitious environmental targets, such as reducing emissions by 55 percent by 2030, says Simon Hinterholzer, a researcher at Germany’s Borderstep Institute for Innovation and Sustainability. In the past two years, these projects have become more popular as energy prices in Europe have soared, prompting local authorities to look for cheap sources of heat to replace Russian gas. “There is definitely a connection to the war in Ukraine,” adds Hinterholzer.
Once the data centers are built, researchers agree that these heat-reuse projects make sense. “It makes a significant difference,” said Shaolei Ren, an associate professor specializing in sustainable computing at the University of California, Riverside. Wren estimates that cooling technology can contribute up to 50 percent of the total energy consumption in a data center. “If companies reuse the heat, they’re essentially reducing the energy needed for cooling.”
But to argue that there are benefits to heat reuse projects, there needs to be an examination of where data centers derive their energy to begin with. Equinix says PA10 energy needs are 100 percent “met” by renewables, including through the use of power purchase agreements (PPAs), where technology companies pay wind or solar farms for the equivalent power they produce, even if this energy is not directly associated with a data center.
“At this point, there is no data center that runs entirely on renewables,” says Wren. “When technology companies claim to run their data centers with renewable energy sources or say they are carbon neutral, they mean carbon offsetting, meaning that they plug their data center into the power grid and implement some offsetting methods elsewhere . ” Companies that rely on PPAs, for example, don’t always buy renewable energy from the same country where their data centers are based.
For the past nine days, the roar of the crowds at the Olympic pool may have overshadowed the noise of the nearby Equinix data center. But in Paris, as in other parts of Europe, skepticism remains about this burgeoning industry and the disruption AI will introduce. The main problem, according to Ligozat, is the debate over the continued construction of data centers and what applications they should be used for. “For me, the big question is, should we keep building data centers?” she says. “And no, do we have to use the heat again?”
