Liquid cooling technology has been steadily gaining traction in the data center industry due to its ability to efficiently dissipate heat generated by HPC’s (high-performance computing systems).
Many have steadfastly cooled vast white spaces with air, with no intention of adopting other cooling methods. According to an Uptime Institute survey, a majority of enterprise IT operators (85 percent) do not employ direct liquid cooling. Interestingly, the percentage of operators unwilling to implement it (22%) surpasses those who do (16%).
Adoption pace hinges on factors like data center operators’ needs, liquid cooling solutions’ maturity and cost-effectiveness, and industry trends.
While it is difficult to provide an exact timeline for when all data centers will adopt liquid cooling, it’s evident that the trend is moving in that direction.
Go With The Flow?
First, let’s consider HPC’s. Liquid cooling is standard practice and all the leading supercomputers use it. It’s one place where power densities are high enough to make liquid cooling the only sensible option. Similarly, hyperscalers are also prone to using it, when the situation demands.
Next, there are two relatively recent, small announcements which signal increased interest.
One is an investment in a liquid cooling company. GRC (formerly Green Revolution Cooling) got a $28 million round of funding led by a whopping $25 million from SK Lubricants of Korea. Some people clearly see a serious future for the concept. There’s a little more to this: SK Lubricants is a petrochemical company keen to gather some green credibility, and it sees GRC as a way to develop a new business line that has environmental credentials.
The other is a company named Inspur who opened up a liquid cooled rack it makes for Chinese cloud giant JD to more customers. They built it in a factory capable of producing 100,000 liquid-cooled servers annually, selling them pre-bundled into racks. So Inspur, too, thinks liquid cooling is heading for a bigger market.
The Bigger Picture
To combat global warming and achieve decarbonization, it is crucial for the world to cease burning fossil fuels. The most challenging sectors to decarbonize are transportation, reliant on oil, and building heating, often fueled by natural gas. These practices have been justified due to factors such as cost efficiency. For example, in the UK, gas is approximately six times cheaper than electricity for heating purposes. Transitioning from gas to renewable electricity for home heating must be economically viable.
Max Schulze from the Sustainable Digital Infrastructure Association emphasizes the shift in value resulting from this change, stating that: “Now, heat is a very valuable commodity, especially when made from electricity.” Data centers, in particular, consume significant amounts of electricity, leading to concerns in certain regions like Ireland. Financially capable data centers can switch to essential renewable energy sources for decarbonizing the power grid. In Denmark, rapid data center growth threatened renewable energy targets, prompting slower development.
Consequently, there is a growing resistance to the construction of data centers. However, we must recognize that using electricity inevitably produces heat. Therefore, data centers could potentially provide a solution to this problem. Temperate countries should use renewable electricity to heat residential and commercial spaces. By purchasing renewable power and utilizing it for their operations, data centers effectively generate heat from renewable energy. They can then share or sell this heat to those in need.
Nevertheless, data centers currently generate heat in the wrong locations and of the wrong type. In the future, it may be advantageous for them to adopt liquid cooling methods to produce optimal heat.
Looking North
Data centers have an incredible potential to contribute to heat sharing initiatives by redirecting their hot air into district heating systems. While challenges may arise, some Northern European countries, where more than 50% of district heat is fueled by renewables, are actively implementing innovative solutions to maximize the utilization of this excess heat.
In Finland, Microsoft has taken a proactive approach by strategically locating its new region next to a Fortum energy plant, ensuring effective utilization of its hot air. Similarly, Sweden’s Stockholm Data Parks initiative has created an inviting space for data centers by establishing a site already connected to district heating. These initiatives showcase how air-cooled data centers can actively minimize heat wastage, unless more groundbreaking strategies such as Qarnot’s approach, which involves breaking down data centers into pieces installed as “digital boilers” in homes, are pursued.
In Norway, data centers are mandated to “consider” the reclamation of waste heat, although this may sometimes involve producing reports to demonstrate the lack of economic viability. Nevertheless, developers are constructing numerous data centers with external vents, denoting them as “heat reuse ready” and ensuring that the responsibility for heat reuse is shared. Across Europe, the Climate Neutral Data Center Pact is propelling data centers towards carbon neutrality. While acknowledging the importance of heat reuse and actively seeking opportunities, the pact may reveal limitations due to its focus on economic viability.
These examples and initiatives highlight the industry’s commitment to exploring and implementing heat reuse strategies, creating a positive trajectory towards more sustainable and efficient data center operations throughout Europe.
Immersion Cooling Examples
- Microsoft’s Project Natick: This is an innovative experiment that involves deploying data centers underwater. One aspect of this project involves using liquid cooling to manage heat dissipation in the submerged data center. In this setup, servers are submerged in a specialized non-conductive liquid coolant, which absorbs heat generated by the components. The liquid coolant is circulated through heat exchangers, and the heat is transferred to the surrounding water. This approach eliminates traditional air cooling, leveraging water’s natural cooling properties.
- Google’s Immersion Cooling: Google has also been exploring liquid cooling technologies for their data centers. In one instance, Google adopted an immersion cooling solution developed by a company called Submer. This solution involves submerging entire servers in a non-conductive liquid coolant. The coolant directly comes into contact with the components, efficiently absorbing heat. By eliminating the need for air cooling, this immersion cooling method allows for higher density server deployments and reduces energy consumption. Google’s adoption of immersion cooling demonstrates the potential of liquid cooling to address the challenges of cooling high-performance computing systems in data centers.
- NVIDIA’s DGX A100 Systems: NVIDIA, a leading provider of graphics processing units (GPUs) and AI computing solutions, has integrated liquid cooling into its DGX A100 systems. Designers create these systems for AI and high-performance computing workloads. NVIDIA utilizes a liquid cooling solution known as the “Direct Liquid Cooling” (DLC) technology. With DLC, engineers bring coolant directly into contact with the GPUs, effectively dissipating the heat generated by these powerful processors. Liquid cooling allows for more efficient cooling of the high-density GPUs, enabling optimal performance and reducing the reliance on traditional air cooling methods.
- Oak Ridge National Laboratory’s Summit Supercomputer incorporates liquid cooling for effective heat management, ranking among the world’s most powerful. Summit utilizes a hybrid cooling system that combines traditional air cooling with liquid cooling. The liquid cooling solution, developed by IBM, involves copper plates attached to the processors, which are in turn connected to a liquid coolant circulation system. This setup efficiently removes heat from the processors and prevents overheating. By implementing liquid cooling, Summit achieves optimal performance while maintaining energy efficiency and reducing cooling costs.
These examples highlight how different ways leverage liquid cooling to address the increasing heat challenges in data centers. Liquid cooling offers unique advantages in cooling efficiency, density, and energy savings, from underwater deployments to server immersion to integration into specific hardware systems.
Inevitability
At some point, these regulations and promises may have to start delivering – and at that point, the only way to share data center heat on a massive scale will be to improve its quality. It will take a lot of collaboration but at some point there will be a market for data center heat. Data centers will soon find it financially beneficial to embrace liquid cooling for superior heat generation. In fact, it might even become mandatory for them to do so.
The data center market doesn’t always follow logic, but there is a reasonable argument that the data center market will eventually have to go with the flow.
