Glossary · Data Center · Efficiency
PUE — Power Usage Effectiveness
The standard metric for measuring data center energy efficiency.
Definition
PUE = Total Facility Power ÷ IT Equipment Power
Power Usage Effectiveness (PUE) was developed by The Green Grid and is the industry-standard metric for data center energy efficiency. It compares the total power consumed by the facility (IT equipment plus cooling, power distribution, lighting) to the power consumed by IT equipment alone.
(theoretical)
(Uptime Institute 2023)
(Google, AWS, Microsoft)
How climate affects PUE
Cooling is 30–40% of typical data center energy use. Lower ambient temperatures reduce mechanical refrigeration requirements, improving PUE without additional capital expense. The Resita site's mean ambient is approximately 2–3°C below primary Western European data center markets.
PUE at Resita
With river water available from the Bârzava (mean flow 3.63 m³/s) for evaporative or adiabatic cooling, and a cooler microclimate, the Resita site is consistent with sub-1.3 PUE in properly designed AI or HPC facilities. Exact PUE depends on facility design choices made by the development partner.