Researchers at Microsoft have examined the environmental impact of different data centre cooling technologies from cradle to grave, in a new report published in the Nature journal.
The report, Using life cycle assessment to drive innovation for sustainable cool clouds, analysed four cooling technologies – traditional air cooling, cold plates, one-phase immersion, and two-phase immersion – as well as going beyond data centre operations themselves to explore the full lifecycle of the infrastructure involved, from raw material extraction and manufacturing to transportation, usage, and disposal.
By highlighting this process, Microsoft said that it hopes companies can develop data centres that use less carbon, energy and water.
Environmental impact
“A lot of people do life cycle assessments after the fact,” to understand a data centre’s environmental impact after it’s built, commented Husam Alissa, director of systems technology in Cloud Operations and Innovation at Microsoft and leader of the lifecycle assessment study.
“When we’re trying to make future design decisions, we typically look at total cost of ownership, performance, sustainability and other factors. We’re advocating in this paper for the use of life cycle assessment tools to guide engineering decisions early on and also sharing the tool with the industry to make adoption easier.”
In terms of the various cooling technologies proposed, Microsoft’s research found that cold plate cooling reduces greenhouse gas emissions and energy use by roughly 15%, and cuts water consumption by 30% to 50%, compared to air cooling.
The two immersion methods also achieved impressive reductions, but two-phase immersion raised environmental concerns due to the use of PFAS chemicals.
“It was interesting to see that cold plates could be as good as the two immersion cooling methods,” added Teresa Nick, director, natural systems and sustainability for Cloud Operations and Innovation at Microsoft and co-author of the paper.
Energy sources
The switching of energy sources was another area in which emissions could be reduced significantly – regardless of the cooling method used, data centre emissions were reduced by between 85% and 90% when said centres relied on 100% renewable energy.
The research effort took more than two years to complete, Microsoft noted.
“In a nutshell, we’re trying to understand the trade-offs,” Nick added. “You’re trying to understand the context of what you’re doing and what the impacts are.” Read more here and here.
