How Are Companies Cooling Data Centres Without Water?

As data centres expand their capacity to keep up with the AI and cloud computing demands, their technology's environmental footprint — particularly in water usage — is facing increased scrutiny.

Historically, many hyperscale data centres have relied on traditional evaporative cooling methods, which can consume vast amounts of water — up to 1.5 million litres per day per site — posing significant challenges in areas facing water scarcity.

In response to these challenges, leading technology firms are pioneering closed-loop and immersion cooling systems that not only limit water consumption but also maintain high performance standards.

The shift to zero water cooling

Data centre cooling systems have traditionally leveraged open-loop water systems for heat management.

However, these solutions are becoming untenable due to global warming and the associated risks of climate-induced droughts and water scarcity.

The industry's transition to more sustainable mechanical cooling solutions results in meaningful advances in infrastructure design, moving towards closed-loop liquid cooling systems.

In August 2024, Microsoft implemented closed-loop, chip-level cooling systems in some of its data centres, effectively eradicating the dependency on evaporative water use.

The system circulates coolant without additional water, saving upwards of 125 million litres annually per data centre.

This advancement builds on Microsoft's previous achievements in reducing water usage.

Between 2021 and 2024, it achieved a significant decrease in Water Usage Effectiveness (WUE), lowering it from 0.49 L/kWh to 0.30 L/kWh.

With these innovations, all new projects from August 2024 onwards will incorporate zero-water cooling designs.

Apart from cutting water use, these systems enable precise temperature management at the chip level, supporting high-density AI workloads and drastically reducing dependency on local water sources.

Closed-loop liquid cooling systems

Microsoft is at the forefront of closed-loop liquid cooling adoption, which circulates coolant within a sealed system between servers and cooling units.

Once initially set up, the system eliminates the need for further water input, effectively halting unnecessary water consumption.

This strategic design facilitates accurate chip-level cooling while negating reliance on municipal water systems.“These new liquid cooling technologies are designed to circulate water within a closed network," says Steve Solomon, Vice President of Data Centre Infrastructure Engineering at Microsoft.

"Once the initial setup is complete, the system operates independently, dissipating heat efficiently without additional water intake.”

Since its deployment, Microsoft has achieved an 80% improvement in Water Usage Effectiveness (WUE) compared to earlier models.

Further initiatives are underway with Singapore-based Evolution Data Centres, which utilises fully air-cooled, closed-loop systems to operate reliably in hot, humid climates without relying on regional water supplies.

This model is particularly beneficial for urbanising regions with growing digital infrastructure demands.

Immersion cooling

Companies like LiquidStack and Iceotope are progressing the field through immersion cooling technologies.

By submerging servers in engineered, non-conductive fluids, these systems achieve cooling energy reductions of more than 90%.

These solutions are ideal for high-density environments like AI processing nodes.

“Data centre operators recognise the benefits of liquid cooling but need assurance around long-term fluid management,” says Peter Huang, Global Vice President of Data Centre Thermal Management at Castrol.​​​​​​​

“Castrol has delivered fluid services for the automotive industry for decades – we're now bringing this proven expertise to data centres with a service model that supports optimal performance throughout the entire lifecycle.”

Hybrid cooling solutions

Developed in collaboration with Vertiv, Bridge Data Centres and Chindata Group, X-Cooling technology employs air and ambient thermal controls to manage temperatures without water use in hyperscale data centres.

The X-Cooling system is proving to be an effective method, achieving zero WUE and a low Partial PUE.

In China’s Hebei Province, implementing such systems is estimated to conserve up to 1.2 million tons of water annually for every 100MW, marking a substantial conservation contribution in the industry.

Vertiv’s Liebert XDU model amalgamates closed-loop liquid cooling and air-based support, representing a stepping stone for data centres moving away from traditional infrastructure towards more sustainable operations.

Industry-wide Impact of cooling innovations

The collective effect of these advancements represents a considerable stride forward for the industry:

• Annual water savings of more than 125 million litres per data centre.
  
• Drastic reductions in WUE, with near-zero usage now achievable.
  
• Better alignment with sustainability targets, especially in regions under water stress.
  
• Improved PUE, as the ability to operate at higher temperatures enables the use of more efficient chillers.

Investments in zero-water cooling are not solely about operational efficiency.

The evolution from water-heavy cooling approaches to more sustainable closed-loop and immersion solutions aligns with a broader industry recognition of climate risks and resource constraints.

With industry leaders such as Microsoft, Chindata, Bridge Data Centres, Evolution DC, Vertiv, Iceotope and LiquidStack, the drive towards sustainable data centre cooling strategies underscores a commitment to innovation and environmental stewardship.