Can Lower PUE Hide Higher Water Use in an AI Data Center?
Yes. A lower PUE can accompany higher on-site water use, because PUE measures energy overhead, not water demand. Evaporative cooling can trade water for lower cooling electricity. Separately, a growing AI workload can increase total water use even when both PUE and WUE improve. Read the two ratios alongside absolute energy, water volumes, and the same measurement boundary. The decision in 30 seconds Ask for annual facility kWh, annual IT kWh, annual water liters, and the water numerator's definition. Then ask where and when the water is needed. A better efficiency ratio is useful evidence; it is not a complete answer to a site's resource constraints. Checked October 28, 2026. This is an interpretation guide, not a measured cooling comparison. All A/B/C figures below are invented annual scenarios. Fifteen arithmetic assertions ran on Node.js v24.14.1 on Windows; no data-center meters, GPU workloads, cooling equipment, or LLMs were operated. Contents and working definitions ...