Cooling Data Centers When Water is Scarce, Part 1

Cloud service providers, colocation vendors, and enterprise data center managers are bowing to the environmental directive to “reduce, reuse, and recycle.”

More than 2.7 billion people around the globe currently suffer from water scarcity, according to World Wildlife Fund. Unfortunately, due to changes in consumption and climate, over two-thirds of the population may face water shortages by 2025.

Water scarcity is a humanitarian issue, as well as a cause of social and political unrest. Soon, more than 5 billion people won’t reliably have enough water to meet their daily needs, yet the world is also striving to invite these same families into the global digital economy.

This puts the data center industry on the horns of dilemma, experiencing a rapid expansion in demand as well as a pressing need to curb our water use while we grow.

The Water Status of the Industry

Data centers are notoriously thirsty enterprises. When extreme drought hit California, for example, the industry came under attack for gulping 158,000 Olympic-sized swimming pools’ worth of already limited water supplies every year.

Sadly, the quest for energy efficiency has often tipped the balance toward more water use. Adiabatic cooling—evaporating water to remove heat—lowers overall power consumption but at a high water cost. Massive cooling towers are particularly prevalent in hot climates and desert regions already experiencing water pressures. This is how in places like Maharashtra, India, the government can be forced to import drinking water for inhabitants even as large colocation facilities proliferate.

Cloud service providers, colocation vendors, and enterprise data center managers are bowing to the environmental directive to “reduce, reuse, and recycle.” From redesigning HVAC systems for greater efficiency to employing municipal wastewater in place of freshwater supplies, the industry is working to shrink the impact of its cooling needs. But we still must do more to save off an accelerating water crisis. Fortunately, solutions are emerging.

Siting Strategies

One of the best ways to avoid excessive cooling requirements, of course, is to avoid being where it’s hot. This means siting decisions play an important role in determining water consumption. Iceland, for one, has grown popular with data center providers because of its climate, and Canada, Finland, and other chillier locales are also attracting interest.

Because it would be impossible to serve the entire globe’s data demands from the Arctic, if for no other reason than latency, the data center industry is also exploring other options. These include building underground. Facilities, like the Lefdal Mine Data Center in Norway and the Guian Seven Stars Data Centre in China, located within a cavern, benefit from the consistently lower temperatures a few meters down. Other abandoned industrial sites and geologically interesting spots worldwide are being examined for potential build-outs.

Then there is Microsoft, which made headlines by going deep underwater. The company recently sunk a submarine-like pod with 864 servers capable of storing 27.6 petabytes of data off Scotland’s Orkney Islands. As much of the ocean is about 0° C, should this “Project Natick” continue to show promise, submerged data centers could offer a means for the industry to alleviate significant cooling-related water-use issues.

And there is another direction—one can go up to secure cooling advantages as well. Temperatures drop approximately 6.4° C for every kilometer of altitude. This is driving growth in the data center market in places like the Rocky Mountains of North America. The world’s loftiest data center currently stands above 5 kilometers in the Chilean Andes, although challenges to building and operating at those heights made it an expensive gambit, albeit a necessary one for its astronomy research purposes.

And we could go farther up, all the way into space. Progress is being made toward commercial data centers in orbit. Price reductions driven by privatized space flight, technology’s ongoing miniaturization, and advancements in “lights out” data centers are transforming a sci-fi dream into a real possibility. Several companies are now testing software-based equipment hardening, distributed satellite backup clusters, and other concepts for cost-efficiently protecting vulnerable equipment and data from solar flares and radiation, another key step toward full-scale data centers in the final frontier.