Chapter 09 · Sustainability & AISustainability & AI
Water usage effectiveness (WUE)
Definition
A data-centre metric dividing annual water consumption by the energy delivered to IT equipment, expressed in litres per kilowatt-hour.
References
This source provides part of the technical or institutional basis for the definition.
This source supports the explanation of how the term is applied, measured or governed in practice.
Overview
What it means
WUE was developed by The Green Grid and standardised in the ISO/IEC 30134 series (part 9). Like PUE it is a site-level operational KPI; it covers operational water, not the water embodied in electricity generation or hardware, so it understates full water impact.
How it is used
Operators report WUE to efficiency programmes and under the EU data-centre reporting scheme, where it is a required indicator. It is used in siting decisions, cooling-technology selection and sustainability claims — where its boundary limitations deserve scrutiny.
Why it matters
WUE makes operational data-centre water use measurable and comparable, but it is not a complete water-footprint measure. It excludes embodied water in hardware and may exclude water associated with electricity generation, so it should not be presented as an overall sustainability score.