A lot of effort has gone in to greening up data centers from an energy use standpoint. The industry is hard at work to achieve carbon neutrality.
Less attention is given to water, even though, unlike energy, water lacks alternatives. Global water use has increased sixfold over the past 100 years, as our economy has grown. Consumption growth is expected to continue to increase by 1% every year.[1] As water becomes increasingly scarce, we expect more attention to be given to conservation with regulations and standards to follow.
Why the lack of focus on water?
There are a couple of issues behind the lack of attention paid to data centers’ water usage.
For one, data centers are increasingly critical infrastructure. As my colleague Sudhir Karla noted in his recent blog “Bringing utility-level reliability to data centers” , COVID 19 elevated data centers from resource to utility in a matter of weeks as the world transitioned to working, learning and streaming entertainment from home. There is intense demand for more data center capacity. Now doesn’t seem to be the time to slow down and rethink how data centers are designed and operated…or cooled.
There is also a matter of perception. Water is perceived to be plentiful. It falls from the sky, after all. And more than 70% of the earth’s surface is covered in it. But of course, we know much of that water is inaccessible or unusable leaving us facing a global water shortage. The UN encourages countries and regions to be proactive in treating water as a scarce resource.[2]
The Department of Energy estimates that the average data center consumes 1.8 liters of water to cool every kWh it consumes, while some industry experts estimate a higher volume of around 5 liters/kWh. [3] Using the lower estimate of 1.8 liters/kW, a 30MW datacenters will consume 1.3 million liters/day or 343,000 gallons/day. To put it in perspective, the average consumer uses about 80-100 gallons of water/day[4], or 142 liters in the UK[5].
Solutions
There is movement in the right direction. Sustainable water strategies include both sourcing and design. On the sourcing front, some hyperscale facilities are starting to include on-site water treatment facilities to tap into local, non-potable water sources. In places like Singapore, non-potable water usage is mandated for water cooled systems. Local municipalities have also put a cap on the amount of fresh water that can be consumed by a datacenter facility.
On the design front, more and more providers are choosing cooling systems with minimal need for water. Others are incorporating rainwater recovery strategies to capture rain, store it on site and use it for cooling to reduce burden on local water supplies.
A redesign is no small undertaking. Replicability in data center design makes it possible to build them quickly and affordably. Deviating from a design plan or retrofitting has trickle down effects into the supply chain which make it a major undertaking. All to say, design shifts will evolve slowly.
Since its inception, Compass has used a waterless airside cooling design. Free and 100% renewable, air is drawn into the facility through finely calibrated filters (to remove particulates) and used to cool the facility. While certain areas of the country have more “Free Cooling” hours than others, there is virtually nowhere in the country where it can’t be used. Even Houston, Texas provides over 3,600 hours of “free cooling” annually. Thus, Compass Datacenters can operate in even the most drought-stricken areas of the country.
Just in time
The pivot toward more water-friendly solutions comes as water availability is a major concern in the context of climate change. Like minimizing power use and investing in renewables gained focus and importance over the last decade, we’re pivoting to develop solutions to minimize the industry’s impact on water. New KPIs such as Water Usage Effectiveness and Carbon Usage Effectiveness are becoming the driving force for datacenter designs and selection.
Since day one, Compass saw a zero-water solution as a mandate. We’re glad to see more industry peers taking a harder look at their impact too so that, as a whole, our industry can lead in doing what’s right by the environment.
[1] https://unesdoc.unesco.org/ark:/48223/pf0000372985.locale=en
[2] https://www.unwater.org/water-facts/scarcity/
[3] Grace Communications Foundation Water Footprint Calculator https://www.watercalculator.org/footprint/data-centers-water-use/
[4] USGS water science school
[5] Water UK. https://www.water.org.uk/news-item/vast-majority-of-brits-have-no-idea-how-much-water-they-use-each-day/
