Feb 29, 2020 - Energy & Environment

Study: Data centers use less energy than expected

Close-up photo of cables and LED lights in a computer server

Cables and LED lights in a computer server in Berlin. Photo: Thomas Koehler/Getty Images

Overall energy use from data centers has increased slightly over the past decade, but improved efficiency means that they're using less energy per operation, according to a new analysis.

Why it matters: Ultra-efficient server farms have kept energy consumption from growing as fast as data use. But with 5G and AI on the horizon, new innovations will be needed to prevent an explosion in energy use.

Background: As more of daily life migrated to the digital cloud, many environmentalists warned that the energy required to process all that data would create a climate catastrophe.

  • One widely distributed 2019 report estimated the energy needed to power online video streaming would emit over 300 million tons of carbon dioxide a year — 1% of global emissions.
  • The same report estimated the emissions generated by watching 30 minutes of Netflix was equivalent to driving almost 4 miles.

But the new analysis, the first major attempt in a decade to compile a global view of data center energy demands, found that between 2010 and 2018 energy use increased only 6% to 205 TWh — less than the amount of electricity consumed by South Africa.

  • Over the same period of time, data center computing grew by 550%.

How it works: Three major trends have kept data center energy use in check, according to Eric Masanet, an adjunct professor of engineering at Northwestern University and the lead author of the report, published in Science on February 28.

  • IT devices in data centers have grown more efficient. "Just like your laptop or your cellphone, you get more performance out of your IT devices for the same amount of energy," Masanet told me.
  • Big cloud computing companies like Google have consolidated servers in massive data centers that can be run more efficiently than smaller operations.
  • Virtualization allows cloud computing companies to run multiple applications on a single server, further enhancing efficiency.

Masanet compares the changes to a city shifting commuters from individual cars to buses.

  • "A single bus uses more energy than a single car, but it can carry so many more people that the energy per person is greatly reduced," he said. "Similarly, you can minimize the energy use of a server by maximizing how much they're utilized."
  • Google says one of its big data centers is on average twice as energy-efficient as a typical enterprise data center.
  • While Masanet and his colleagues didn't directly measure carbon emissions, many of the biggest cloud computing companies have aggressively purchased renewable energy.

What's next: Data demand is expected to double within the next few years, and as servers run up against the theoretical limits of Moore's Law "continuing those energy efficiency gains is not a guarantee," Masanet said.

  • He and his colleagues call for more stringent IT energy standards, further research into next-generation computing, and incentivization of renewable energy sourcing.

The bottom line: Technology and policy have kept a lid on energy consumption even as data demand has exploded — which means that the only thing you're wasting when you bingewatch Love Is Blind on Netflix is your time.

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