WUE

Water Usage Effectiveness: site water divided by IT energy, for a stated boundary and period.

The Green Grid’s 2011 paper defines site WUE in litres per kilowatt-hour and a source metric that also counts water used to make the electricity. Union reporting under Delegated Regulation (EU) 2024/1364 uses W IN / E IT in cubic metres per megawatt-hour for halls at or above 500 kW IT demand. Those are different cells. A Nordic winter is not a measured WUE.

Common confusions

• Treating outdoor air or “cooling-free” as a WUE of zero.
• Pasting a Union average onto a named Swedish hall.