Despite a huge increase in the compute loads of data centers between 2010 and 2018, actual energy usage rose only marginally, researchers found.

Significant efficiency advances mean that the industry's power demands rose just six percent in the time it took for compute to jump 550 percent. The study - by Northwestern University, Lawrence Berkeley National Laboratory, and Koomey Analytics - is set to be published in the journal Science on February 28.

Good news at last

Power lines
– Thinkstock / zhengzaishuru

Researchers used data from various sources to build a picture of data center energy consumption, including information on data center equipment stocks, efficiency trends, and market structure. The resulting model enables a detailed analysis of the energy used by data center equipment (such as servers, storage devices, and cooling systems), by type of data center (including hyperscale and cloud) and by world region.

The energy efficiency improvements outpaced any other major sector, the researchers said, and mean that data centers are thought to account for one percent of global energy usage.

The study criticized "several oft-cited yet simplistic analyses" that claim the energy used by the world’s data centers has doubled over the past decade and that their energy use will triple or even quadruple within the next decade. "But such extrapolations based on recent service demand growth indicators overlook strong countervailing energy efficiency trends that have occurred in parallel," the study notes.

The paper estimates that in 2005 the worldwide energy use of data centers was 153 terawatt-hours (TWh), 194 TWh by 2010, and 203 TWh in 2018.

But between 2010 and 2018, global data center workloads and compute instances have increased sixfold, data center Internet protocol (IP) traffic has increased by more than 10-fold, and data center storage capacity has increased by an estimated factor of 25.

Looking ahead, the researchers noted the difficulty of predicting the future, but said that improvements such as greater levels of server virtualization, shifts to low-power storage devices, and structural moves from small, inefficient data centers to hyperscale facilities should ensure that "there is a sufficient energy efficiency resource to absorb the next doubling of data center compute instances that would occur in parallel with a negligible increase in global data center energy use."

We still have work to do

Despite the positive news, the study's lead, Eric Masanet, cautioned: “While the historical efficiency progress made by data centers is remarkable, our findings do not mean that the IT industry and policymakers can rest on their laurels.”

“We think there is enough remaining efficiency potential to last several more years. But ever-growing demand for data means that everyone - including policymakers, data center operators, equipment manufacturers, and data consumers - must intensify efforts to avoid a possible sharp rise in energy use later this decade.”

Coauthor Arman Shehabi, LBNL research scientist, added: "Considering that data centers are energy-intensive enterprises in a rapidly evolving industry, we do need to analyze them rigorously. Less detailed analyses have predicted rapid growth in data center energy use, but without fully considering the historical efficiency progress made by the industry. When we include that missing piece, a different picture of our digital lifestyles emerges.”

Opening up

Speaking to DCD, Shehabi said that such research could be improved further by more transparency in the industry, and urged that data center operators contact the paper's researchers to confidentially share details about their facilities. Everyone in the industry could be more open, but data that was particularly hard to come by was from enterprises with in-house data centers, and from Chinese companies in general.

“Lack of data has hampered our understanding of global data center energy use trends for many years,” coauthor Jonathan Koomey of Koomey Analytics said. "Such knowledge gaps make business and policy planning incredibly difficult.”

The models and data sets used in the Recalibrating global data center energy-use estimates study will be made public.

The researchers also made three specific policy recommendations:

  1. Extend the life of current efficiency trends by strengthening IT energy standards such as ENERGY STAR, providing financial incentives, and disseminating best energy efficiency practices
  2. Increase R&D investments in next-generation computing, storage, and heat removal technologies to mitigate future energy use, while incentivizing renewable energy procurement to mitigate carbon emissions in parallel
  3. Invest in data collection, modeling, and monitoring activities to eliminate blind spots and enable more robust data center energy policy decisions

In its conclusion, the paper warned: "Given the important role data centers will play in future energy systems, the historical dearth of knowledge on their energy use and the mixed signals given to policymakers by contradictory findings are unacceptable. Global data center energy use is entering a critical transition phase; to ensure a low-carbon and energy-efficient future, we cannot wait another decade for the next reliable bottom-up estimates."

For the next issue of DCD Magazine, we talk to Shehabi, as well as several other researchers, industry figures, and government officials about the impact of climate change on the data center industry. From the sea level rising, to wildfires and hurricanes, are you ready? Subscribe for free today.