Big Tech’s AI data center push is spawning a new heat economy

Students at a technology university in Dublin are enjoying an unexpected advantage of artificial intelligence; AI is helping heat their campuses.

Since 2023, Dublin Technical University’s Tallaght campus has been one of a growing number of campuses. Buildings in the city’s southwest suburban area will be heated by waste heat from a nearby Amazon Web Services data center.

Data centers have always produced excess heat, but integration with district heating networks has been slow because the waste heat produced by these energy-hungry facilities is often too low temperature to directly heat other buildings.

This is now changing. As the AI ​​boom begins and data centers become increasingly filled with racks of advanced chips requiring up to three times the computing capacity of before, operators have had to find new ways to balance maximizing efficiency without sacrificing sustainability.

Artificial intelligence is a “twist” that makes it more appealing, according to Adam Fabricius, commercial director at heating, ventilation and air conditioning equipment provider Sav Systems and heat networks researcher at sister company EnergiRaven.

“What’s exciting is that AI can give you higher temperatures, and water cooling makes that a lot easier. You need a lot less hardware to connect those systems,” he told CNBC.

Brendan Reidenbach of the International Energy Agency told CNBC that providing heat to the district heating network gives data centers “additional social license.”

“On paper it may not ultimately be very cost-effective, but it contributes to that good social impact by turning the potentially bad news story of the proliferation of data centers into the good news story of ultimately decarbonised heat supply. So it’s very much a win-win situation,” he added.

There’s a fair amount of uptake among Big Tech. Microsoft Høje-Taastrup in Denmark announced plans to feed the district heating network; ONE Equinox data center heats 1,000 homes in Paris; And Google made a big statement heat recovery project at its facility in Hamina, Finland.

Ireland was one of two European countries to impose a moratorium on new data center applications as electricity-hungry facilities strained Dublin’s grid and depleted consumers. 22% of the small country’s power Ireland eventually eased its moratorium late last year as the AI ​​boom created a sense of a U-turn on the economic potential of the plants.

The IEA’s Reidenbach said Ireland was “really a blank slate” as it had not previously had district heating. He said the Tallaght plan demonstrated the benefits of integrated planning because it brought together the power system operator and the distribution network operator.

In 2020 the local government established Heat Works, Ireland’s first not-for-profit energy organisation. Waste heat from the nearby AWS data center provides 100% of the heat to the network.

“Although we are only in our second year of monitoring, we have evidence that the project is limiting our exposure to market price shocks overall,” TU Dublin head of decarbonisation Rosie Webb told CNBC via email.

According to TU Dublin’s calculations, the campus will reduce carbon dioxide by approximately 704 metric tonnes in 2024, despite additional energy demand from two new buildings added to the site.

AWS’s data center in Tallaght offers a “unique opportunity” for heat reuse, according to the company’s country leader Niamh Gallagher. The scheme, which sees AWS providing free recycled heat, was initially planned to heat 55,000 square meters of public buildings – an area three times the size of the city’s Croke Park stadium ground – as well as commercial space and 133 flats.

“When we can identify a specific project that uses our infrastructure to support the community’s climate goals, it’s a win-win situation,” Gallagher told CNBC.

When it comes to heating networks, Europe is much more advanced than the United States, according to Ben Hertz-Shargel, head of global grid edge at energy research firm Wood Mackenzie.

Some midsize data centers located closer to metropolitan areas are probably best positioned to provide waste heat, Hertz-Shargel said. An example of this is Equinix, which, like AWS, does not make a profit from the waste heat it provides, he added.

However, delays in permits and high investment costs of building heat networks and integrating data centers into the system make it difficult to scale the model.

There is also lifecycle incompatibility. Reidenbach said the district heating network is typically given a 30-year lifespan, while equipment in the data center is given only seven to 10 years. “This leaves a huge risk that assets will remain idle,” he added.

Nexalus, a thermal and science engineering company that patented its technology from Trinity College Dublin in Ireland, has researched ways to capture heat from the hot GPUs and CPUs housed in data centers.

The company uses jet impingement liquid cooling to increase the performance of the chips while capturing waste heat at much higher temperatures. Instead of producing “low-grade” heat, Nexalus CEO Kenneth O’Mahony told CNBC that it provides output at around 55 to 60 degrees Celsius without using a heat pump; This is hot enough to be reused for direct district heating.

Other data centers typically release excess heat at around 30 to 35 degrees Celsius, making it much less practical for reuse, according to the company, which maps the heat emitting from chips so it can target the hottest areas for cooling.

“It’s like a showerhead on a shower. If you have pain in your shoulder, you point it at the point you want it to go. So we do that and map it out to maximize the impact on each chip,” O’Mahony said.

“We see data centers as energy debtors and actually energy producing centers,” he added. “It should be desirable to place your data center in the construction phase of cities, in the design of apartment blocks… to produce enough heat for your entire building.”

Nexalus is not the only company exploring this technology. Nvidia It caused alarm in the refrigeration market when it was recently introduced. next generation Rubin chips It doesn’t need to be cooled as heavily as previous models.

Rob Pfleging, CEO of modular liquid cooling provider Nautilus Data Technologies, said he “got chills” when he saw Nvidia’s announcement because it has long focused on raising water temperatures to deliver “significantly greater efficiency.”

“The best part about it [Nvidia] the announcement is: [that it’s] we are moving in the right direction because it also allows heat to be reused much more easily,” Pfleging told CNBC.