SUSTAINABILITY
A
s AI and real‐time analytics become business‐critical, data centres globally are under pressure to scale compute density – and with it, cooling capacity. Yet amid the focus on megawatts and Power Usage Effectiveness( PUE), a quieter crisis is unfolding: the growing impact of this computing power on our already-stressed freshwater resources.
Data centre water consumption is not solely from on-site evaporative cooling. On average, 4.3 litres of water are consumed to generate a kWh of energy.
With data centre power use projected to double by 2030 in Europe, water stress will only increase.
Here, we speak with Matt McMullen, Senior Corporate Account Manager, Global High Tech at Ecolab, on the mutually rising tides of data and water.
Q. WHY DOES WATER MATTER IN DATA CENTRE COOLING?
»“ Cooling towers and other evaporative systems can provide energy efficiency, reliability, and cost savings and have long been the backbone of facility‐scale temperature control,” begins Matt.“ However, in regions classified as water‐stressed, even municipal supply can face seasonal shortages. A key industry improvement to deal with this challenge is the use of datadriven decision making, namely Water Usage Effectiveness( WUE).”
WUE, first introduced by The Green Grid in 2011, considers litres of water used per kWh of IT load to provide operators and data centre design professionals with a comparable KPI, much as PUE did for power.
“ Added analysis accounting for water consumed from power generation( WUE), local water stress factors( WS) and use of sustainable water sources have helped give a more accurate KPI for actual local water stress impact,” says Matt.
“ These WUE metrics show that innovations like adiabatic cooling and the use of greywater, or industrial reclaim, have helped relieve some water stress.
“ Another potentially large WUE improvement has come as a result of leveraging direct-to-chip( D2C) liquid cooling to answer the AI-driven need to cool chips with higher heat densities.”
“ A KEY INDUSTRY IMPROVEMENT TO DEAL WITH THIS CHALLENGE IS THE USE OF DATA- DRIVEN DECISION MAKING, NAMELY WATER USAGE EFFECTIVENESS”
Matt McMullen, Senior Corporate Account Manager, Global High Tech, Ecolab
84 October 2025