Climate Change Threatens Supercomputers

Increasingly intense heat waves, wildfires, and droughts are forcing costly adaptations.

Source: Getty Images, Adapted by M. Atarod/Science

In 2018, during a savage drought, the California wildfire known as the Camp Fire burned 620 km2 of land, reducing several towns nearly to ashes and killing at least 85 people. The disaster also had a ripple effect far from the flames, at a supercomputer facility operated by Lawrence Berkeley National Laboratory (LBNL) 230 km away. The National Energy Research Scientific Computing Center (NERSC) typically relies on outside air to help cool its hot electronics. But smoke and soot from the fire forced engineers to cool recirculated air, driving up humidity levels.

“That’s when we discovered, ‘Wow, this is a real event,’” said Norm Bourassa, an energy performance engineer at NERSC, which serves about 3,000 users a year in fields from cosmology to advanced materials. Hot and dry weather took a toll again a year later. California utilities cut NERSC’s power for fear that winds near LBNL might blow trees into power lines, sparking new fires. Although NERSC has backup generators, many machines were shut down for days, Bourassa said.

Managers at high-performance computing (HPC) facilities are waking up to the costly effects of climate change and the wildfires and storms it is intensifying. With their heavy demands for cooling and massive appetite for energy, HPC centers—which include both supercomputers and data centers—are vulnerable, said Natalie Bates, chair of an HPC energy efficiency working group set up by Lawrence Livermore National Laboratory. “Weather extremes are making the design and location of supercomputers far more difficult.”

Climate change can bring not only heat but also increased humidity, reducing the efficiency of the evaporative coolers many HPC centers rely on. Humidity can also threaten the computers themselves, as NERSC discovered during a second fire. As interior air was recirculated, condensation inside server racks led to a blowout in one cabinet, Bourassa said. For its next supercomputer, set to open in 2026, NERSC is planning to install power-hungry chiller units, similar to air conditioners, that would both cool and dehumidify outside air.

The cost of such adaptations is motivating some HPC centers to migrate to cooler and drier climates, places such as Canada and Finland, said Nicolas Dubé, chief technologist for Hewlett Packard Enterprise’s HPC division. “We can’t build in some locations going forward, it just doesn’t make sense,” he says. “We need to move north.”

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