Data centres are becoming hugely important infrastructure and more than ever are in demand, enabling services like cloud storage, video streaming, and e-commerce. However, behind the scenes, these facilities consume significant resources to keep operations running smoothly. One resource that often goes unnoticed is their huge water consumption, or when noticed becomes a hugely controversial subject.

Buy why do these buildings need so much water?

Cooling: The Primary Role of Water

Servers inside data centres generate enormous amounts of heat as they process and store data. If this heat isn’t managed properly, it will lead to overheating, equipment damage, or costly downtime within a matter of minutes.

Cooling is critical, and that’s where water comes in.

The Impact of Evaporative Cooling

Evaporative cooling is one of the most efficient ways to keep servers cool and upto 90% more efficient than just using traditional refrigerant air-conditioning systems. Evaporative cooling works by using water to absorb heat, which then evaporates to carry the heat away in large cooling towers. While this method is effective, it’s also water-intensive.

To give you an idea of the scale:

• A typical 1-megawatt (MW) data centre using evaporative cooling can consume around 18,500 gallons of water per day.
• Larger hyperscale facilities may use magnitudes more than this, as cooling capacity scales with how large the data centre is

This makes evaporative cooling the biggest contributor to water consumption in most data centres.

Reducing Water Usage in Data Centres

While evaporative cooling is energy-efficient compared to traditional air conditioning, its massive water consumption has raised major concerns, particular in water stressed environments such as Oregon where Google’s datacentre was using a one-third of the cities water usage and growing each year.

The good news is that the industry is working hard to address this issue with smarter designs and new technologies.

1. Using Free Cooling

Free cooling takes advantage of natural resources like cold air or water to cool servers without relying heavily on evaporative systems. Data centres in cooler climates, for example, can use mix filtered outside air during colder months to reduce water and energy use.

Smarter Cooling Systems

Many data centres are adopting innovative methods to cut water consumption, including:

• Closed-loop systems are emerging as economically viable alternative to traditional evaporative coolers that significantly reduce water consumption by recycling the same water repeatedly, rather than continuously drawing new supplies. Microsoft is experimenting with these designs in their next-generation datacentres which are hoped to saved over 125 million litres of water per datacentre per year
• Rainwater harvesting and greywater use: Some facilities are turning to alternative sources like capturing rainwater or recycling wastewater instead of using fresh drinking water.

Conclusion

Water is a key resource for data centres, particularly for cooling, where evaporative cooling plays a major role in traditional data centre cooling solutions. However, the industry is making big strides toward sustainability by introducing smarter designs, adopting more efficient systems and metrics such as WUE (Water Usage Efficiency) to grade data centres.