In the first article of our series about water sustainability in data centers, we discussed current cooling techniques and how to optimize and reduce water consumption. But with technology improving every day, there are plenty of new ways to address those issues. By adopting those strategies and combining them with circular infrastructure, your company can make a significant step towards sustainability. Let’s explore how today!
Stop using drinkable water!
A major initiative in data center sustainability is the shift away from using potable water for cooling. Instead, facilities are turning to alternative sources like recycled and rainwater. The State of the Data Center 2024 report highlights that:
- 29% of data centers plan to collaborate with vendors to create water treatment solutions.
- 22% have started using effluent or graywater recycling.
- 16% are integrating rainwater collection systems.
A notable example of success in this area is the Los Alamos National Laboratory (LANL). Their Sanitary Effluent Reclamation Facility (SERF) uses treated non-potable water for cooling, significantly reducing the need for potable water. By investing in reverse osmosis filters and improved pumps, LANL managed to boost the cycles of concentration — the number of times water can be reused for cooling — from 2.5 to 6, improving both water efficiency and operational availability.
New designs?
Design innovation is also pivotal in reducing water consumption. Some data centers are being built underground or even submerged in water bodies. Microsoft’s Project Natick exemplifies this by submerging a sealed data center off the coast of Scotland. This facility, which ran 864 servers for two years, leveraged seawater for cooling, demonstrating a practical approach to sustainable data center operations.
Another example would be the Facebook’s Prineville data center, which employs an upper-floor system that draws outside air, filters, cools, and humidifies it, achieving a 90% reduction in water usage compared to conventional chiller systems.
Location, location, location
Choosing the right location can greatly impact a data center’s cooling efficiency. Building data centers in cooler climates or regions with ample water sources, such as near lakes or rivers, reduces the strain on local water supplies.
Switch has taken significant measures to operate sustainable data centers in Las Vegas, a water-scarce region. By using 100% recycled effluent, they aim for a net positive water strategy—replenishing more water than they consume. This approach not only conserves water but also builds goodwill with local communities.
Advanced cooling technologies
Cutting-edge technologies continue to evolve, bringing innovative ways to enhance cooling efficiency while minimizing water use. While they are already in use, as we mentioned in our first article, their adoption is not widespread yet and can greatly benefit your water consumption :
- Direct-to-Chip (DtC) Cooling: This involves circulating a cooling liquid directly to the processor (CPU or GPU) plates. As we will see a bit later, companies like Nvidia are integrating this technology alongside advanced two-phase immersion cooling to maximize heat removal while minimizing water use.
- Immersion Cooling: This method involves submerging servers in a nonconductive liquid, which efficiently absorbs heat. While it requires high initial investments, its long-term benefits include reduced water usage and enhanced cooling performance while saving space, increasing rack density and reducing data center noise.
- Air-Cooled Chillers: These chillers use a closed-loop system to maintain cooling without relying on make-up water, providing an eco-friendly alternative to traditional water-cooled systems.
Leveraging AI and digital technologies
The integration of AI and IoT has proven effective for optimizing data center cooling systems. By employing advanced Data Center Infrastructure Management (DCIM) tools, facilities can monitor water and energy consumption in real time and make data-driven decisions to enhance efficiency. Google’s AI initiatives have shown that fine-tuning environmental controls based on real-time data can reduce energy use for cooling by up to 40% (and that was back in 2016, so the optimizations nowadays should be even better).
Additionally, the Computational Fluid Dynamics (CFD) technology that we mentioned in part 1 helps operators map airflow and identify inefficiencies, which aids in better resource allocation and reduced water and energy use.
Waste heat recovery
Harnessing waste heat is another avenue for innovation in data center cooling. In countries like Denmark, Microsoft data centers are channeling waste heat to nearby residential areas for heating. This method not only reduces overall energy consumption but also adds tremendous value to the local community.
The Organic Rankine Cycle (ORC) is a promising technology for repurposing waste heat into electricity. By using an organic working fluid with a low boiling point, ORC systems capture server heat and convert it into mechanical energy, which drives an electric generator. This increases the energy efficiency of data centers and lessens the dependence on traditional water-cooling methods.
Collaborative efforts and incentives
The COOLERCHIPS program, initiated by the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E), focuses on developing advanced cooling technologies for data centers to significantly reduce energy consumption and operational costs, targeting a cooling energy expenditure of less than 5% of a data center’s IT load.
Several cutting-edge solutions are being developed under this program:
- Microconvective Cooling Systems: Companies like JetCool are at the forefront of micro-cooling innovations, focusing on lowering CPU temperatures. JetCool’s technology employs microjets to deliver a precise coolant to critical points, resulting in improved heat dissipation. This system acts as an in-server radiator, eliminating the need for traditional air-cooling systems and providing energy savings of up to 10%.
- Hybrid Immersion Cooling: Flexnode is developing prefabricated edge data centers that integrate microchannel heat sinks and hybrid immersion cooling. These units combine the benefits of liquid cooling with minimal water usage, enhancing sustainability while maintaining optimal performance.
- Advanced Thermal Management Systems: Companies like HRL Laboratories are working on leveraging graphite micro-fins and innovative flow manifold designs. These enhancements can significantly improve heat transfer efficiency, minimize power consumption for cooling, and contribute to a more sustainable data center operation.
- HP’s Microfluidics Research: Using its proprietary inkjet microfluidics technology, HP is researching ways to minimize the thermal interface material required between processors and coolants. This initiative promises to reduce overall cooling energy needs while enhancing thermal management performance.
- Nvidia’s Push for Cooling Efficiency: Nvidia, a leader in AI hardware design, is also contributing by exploring complex cooling solutions. The company is working on systems that integrate direct-to-chip cooling with immersion cooling, all contained within a hermetically sealed chamber. By using green refrigerants and innovative liquid-vapor separators, Nvidia aims to reach an ultra-low thermal resistance of 0.0025°C per watt. This system not only improves cooling efficiency but also minimizes environmental impact through reduced water use.
Conclusion:
Innovation in data center cooling is rapidly evolving as the need for sustainable practices becomes exponentially urgent. From utilizing non-potable water and submerging data centers underwater to adopting advanced AI-driven cooling and waste heat recovery, these forward-thinking strategies offer hope for a more sustainable future. By investing in these innovations and continuing to adopt circular IT practices, data centers can minimize their environmental footprint while maintaining operational efficiency. If you’re ready to take action, please get in touch with us, and we will be happy to guide you every step of the way!
