Water in data centres and the irrelevance thesis

Water has become a central argument in the public debate on data centres. Joaquim Rolim recommends an interview and summarises the thesis: water consumption in modern data centres would be irrelevant.

The fact sheet Data Centers and Water, from the Environmental Law Institute, of January 2026, separates the two figures. Direct water consumption in United States data centres rose from around 21.2 billion litres in 2014 to 66 billion in 2023, according to Lawrence Berkeley National Laboratory data. In the same year, the sector's 176 TWh of electricity implied around 800 billion litres consumed indirectly in generation.

The same fact sheet classifies air cooling and direct-to-chip liquid cooling as low or zero consumption, and evaporative cooling as high, with around 80% of the water lost through evaporation. The post's thesis therefore holds at project level, not at sector level: the water leaves the site and reappears in the energy mix that feeds the site.

For Brazil, the useful reading is one of measurement. The direct figure is resolved in the project, with a closed loop; the indirect one depends on the mix supplying the development and here must also take into account reservoir evaporation. Publishing both indicators per project takes the discussion out of the realm of impression.