ODATA and the myth of water use in data centres

ODATA has published a 79-second video to challenge what it calls the myth of water consumption in data centres. The narration says the perception comes from evaporative systems with cooling towers and that the company's centres use a closed chilled-water loop: after the initial fill, the water exchanges heat, is cooled and returns to the loop, with water use, according to the company, practically zero.

What the piece does not size is the other side of the choice. The report Data Centers and Their Energy Consumption, by the United States Congressional Research Service, dated 26 August 2025, attributes 38% to 40% of a data centre's electricity consumption to cooling and records, citing a supplier, that water-cooled systems can use half the electricity of air-cooled ones.

Swapping evaporation for a closed loop takes pressure off water resources and shifts part of it back onto the energy bill, because the heat that evaporation would dissipate now leaves through a chiller. In a water-stressed region the swap pays off; where the grid is the bottleneck, it shows up in the demand contract.

The engineering choice determines which input becomes scarce first. The useful indicator for anyone assessing a data centre is the pair of water and electricity per installed megawatt.