How to cut water usage in cloud data centers
Water may not be the first word that springs to mind when it comes to huge data centers, but it is fundamental to their operations.
Primarily used in cooling systems to ensure servers don’t overheat, tremendous amounts of water circulate daily in data centers worldwide. As the demand for cloud services keeps surging, major cloud providers build more and more facilities to keep up. Amidst a global water scarcity crisis, sustainable water use becomes imperative for the industry. In an attempt to mitigate the issue, the major CSPs put in place innovative, water-efficient technologies and practices.
How is water utilized in data centers, and why is it so important?
Before we can discuss the implications of water consumption in data centers, we need to understand the reasons behind the high volumes of water usage. The average data center is 100,000 sq ft, with many containing thousands of servers. Each task these servers perform requires energy that translates into heat. With so many machines in place, this heat aggregates, and extreme measures must be taken in order to cool it down and prevent damage to the equipment and services.
Cooling methods in data centers rely mostly on water-based systems, in which large volumes of water absorb and dissipate the heat coming out of the servers. Here is a short explanation of how this works.
Water chillers circulate water through the data center, absorbing heat from the equipment. The heated water is then routed to a cooling tower, allowing the heat to dissipate. The cooled water is recirculated into the data center, and the cycle continues. The problem with this method is that most of the water doesn’t survive the trip. Eighty percent of the water evaporates during this process, leaving behind salts and minerals dissolved in the remaining water. As more water evaporates, the remaining water becomes concentrated, which may cause damage to the system. That means that the water needs to be renewed every few rounds.
On average, between one to nine liters of water are evaporated during the cooling process of one kilowatt hour (kWh), measuring the amount of energy needed to power one machine that consumes 1,000 watts for one hour. The large range stems from variations in the level of efficiency of each data center and the fact that weather conditions may affect the effectiveness of this process. We are talking about vast amounts of water per year, reaching tens of millions of liters per month. According to Google’s 2023 environmental report, its data centers consumed 5.2 billion gallons of water during 2023. That’s an average of approximately 500,000 thousand per data center per day. These are extraordinary numbers.
Implications
The extensive use of water in data centers doesn’t come without a price, taking a toll on environments and economies worldwide. These adverse consequences are especially apparent in areas where water is scarce, with residents expressing concerns that their essential resources are being exploited for the benefit of large corporations at the expense of local needs.
Regions such as North America and Latin America find themselves in a tough spot; while experiencing local water scarcity crises, they’ve had the misfortune of becoming strategically valuable for data center deployments, consuming millions of gallons of water daily. These amounts equal those used by small towns and they exacerbate an already potentially dire situation for these communities. Google intends to replenish 120 percent of the water it consumes by cleaning wastewater and supporting the restoration of natural ecosystems. However, according to its 2023 report, they are currently replenishing six percent.
Sustainable practices and future trends in data center cooling
As the environmental footprint of data centers rises, Google, Amazon, and Microsoft adopt and experiment with innovative methods to minimize water usage. Google, for example, leverages ML to develop predictive cooling systems that dynamically adjust to real-time needs; Amazon explores advanced evaporative cooling and modular data center designs that optimize airflow and minimize cooling requirements. Meanwhile, Microsoft investigates natural cooling resources, such as seawater and geothermal energy, and has experimented with underwater data centers through its Project Natick (though this project has been discontinued.)
These initiatives mark a significant shift toward sustainable data center operations, aiming not just to mitigate the problems but solve them. As a testament to that, Google and Microsoft are working towards becoming water-positive by 2030, reflecting their commitment to reversing water consumption trends.
How can the cloud industry become water-positive?
In order for the cloud industry to achieve these sustainability goals, it must adopt more sustainable practices.
Collecting water usage data is probably the most crucial step. Currently, only half of all data centers track their water usage. Optimizing resources is what we do at Zesty, albeit in a different way, so we know how vital visibility into resource usage is to the goal of minimizing wastage. Without knowing where your usage is high, understanding why and how to mitigate it is almost impossible.
Replacing legacy systems is also essential. By upgrading outdated cooling technologies, data centers can significantly lower their water and energy consumption by leveraging modern, more efficient technologies. We also need to find both new ways to cool data centers and ways to use other water resources for cooling, such as gray water and rainwater harvesting. And we must be more mindful of where we deploy data centers.
Constructing data centers in colder regions is a strategic move that utilizes the natural cold air to aid in cooling, thereby reducing the need for mechanical cooling systems. This geographical strategy not only enhances the sustainability of operations but also cuts down on both energy and water use.
Shaping a sustainable future for the cloud
The high water consumption of cloud data centers poses a significant challenge in the cloud industry and has environmental, economic, and social implications. The pioneering efforts of tech giants like Google, Amazon, and Microsoft demonstrate a commitment to reducing this impact through innovative cooling technologies. However, the destination is still far away and requires continuous innovation and supportive policies to promote sustainable practices industry-wide. By aligning the efforts of industry leaders with practical sustainability initiatives, we can ensure the sustainability of our digital infrastructure and a responsible future for the tech ecosystem.
This article was originally published by Data Center Dynamics.
