Europe’s drive to expand artificial intelligence is fuelling rapid growth in data centres worldwide, pushing up electricity use, carbon emissions and water demand.
Data centres could account for 3% to 4% of global electricity consumption by 2030, and could use around 5 billion cubic metres of water a year by 2027, the European Commission warned in a release on Tuesday.
Researchers have set out ways for data centres to use their “waste heat” — the low-temperature heat produced during computing — to capture carbon dioxide from the air or to purify water, according to the same statement.
The analysis examined “low-grade” waste heat typically in the range of 30°C to 70°C and assessed six possible uses that could work in different locations, including district heating, converting heat back into electricity, and technologies for cooling, water production and carbon removal.
Using projections of US data centre electricity use of about 200 terawatt-hours by 2030, the researchers compared the likely climate and economic impacts of each option after accounting for efficiency and the value of what is produced.
Two options stood out
Two uses performed best on both emissions reductions and economic potential — direct air capture (DAC) of carbon dioxide using waste heat, and thermal water purification to turn seawater or brackish groundwater into drinking water.
DAC refers to technology that removes carbon dioxide directly from ambient air; the researchers estimated waste-heat-powered DAC could remove about 50 to 1,000 megatonnes of CO₂ a year.
Thermal water purification uses heat to produce potable water, with the researchers describing the approach as a way for data centres to become net water producers.
The analysis said both options could outperform more conventional forms of heat recovery such as space heating, partly because they are less dependent on being located near heat users.
The researchers also flagged constraints, including that waste heat may be too cool for some DAC systems while chips must remain within safe operating temperatures, and that using all of a data centre’s heat could require a DAC facility larger than any yet demonstrated.
A study for the European Parliament found DAC could play a role in cutting EU emissions but that current costs are high and uncertain.
The underlying research was published as “Flipping the switch: carbon-negative and water-positive data centers through waste heat utilization” in the journal "Energy & Environmental Science."
