Designing data centres to minimise water use
Public debate about data centre operational water use often overlooks how modern designs can cut consumption to near-negligible levels. At Pure DC, we design and build data centres to minimise operational water demand through a combination of closed-loop cooling, rainwater harvesting, and targeted use of potable water.
Cooling systems are based on a closed-loop water circuit coupled with air-cooled, free-cooling chillers. This approach minimises evaporative losses by recirculating water through the system, only requiring minor top-ups. The design delivers a Water Usage Effectiveness (WUE) of less than 0.001 l/kWh — over a thousand times lower than the consumption rates of some open-loop systems.
Potable water is predominantly used for everyday employee needs like hygiene, toilets, and kitchen facilities. Rainwater harvesting is installed for site irrigation, further reducing mains water demand. Our basis of design includes a WUE target, water metering across the site, and leak detection systems.
We are actively working to remove the need for water in humidification processes at our sites wherever feasible, aiming to reduce yet another core data centre component from requiring natural resource.
At our Brent Cross data centre, the campus will feature almost 750,000 plants to form one of the world’s largest living walls, supporting biodiversity, reducing noise pollution, and improving air quality. We are trialling the addition of biochar to the growing substrate — a first for a living wall globally. Initial results show biochar can cut water use by up to 60%, while also supporting plant health.
Electricity generation from thermal power stations also consumes water, mainly for cooling. By sourcing power through green Power Purchase Agreements (PPAs) for wind and solar, we lower the indirect water footprint associated with the electricity used to run our facilities.
Water use during construction activity is measured by our general contractors, enabling us to monitor and manage total project water demand from day one.
In combination, these measures allow our campuses to operate with one of the lowest water footprints possible — delivering capacity for cloud and AI workloads while conserving and optimising the usage of a critical natural resource.