Spatial distribution and influencing factors of data center water usage effectiveness in China

Abstract

This study evaluates the direct water consumption of data centers using water-side cooling systems in China. A WUE calculation framework is developed by coupling cooling-tower water loss with cooling-system COP. Long-term meteorological data are used to extract representative typical days, which are then used to simulate annual and seasonal WUE patterns across major Chinese cities. The results show a clear spatial pattern: WUE is generally lower in northern and western China and higher in southern and eastern China. For closed-circuit cooling towers, WUE is mostly below 1.0 L/kWh in Northeast China, Northwest China, and the Qinghai–Xizang Plateau, but approaches or exceeds 2.0 L/kWh in hot and humid cities in South China. Among the eight national data center hub regions, the wet-cooling operation ratio is 27.3% in Inner Mongolia, 36.6% in Ningxia, and 52.4% in Gansu, while it reaches 100% in the Pearl River Delta. The results indicate that climate conditions and cooling-control strategies strongly affect water use. In the model, a 7 °C wet-bulb threshold is used for closed-tower dry-wet switching and for identifying open-tower natural-cooling availability, while open-tower air-to-water-ratio modes are classified using seasonal mean dry-bulb temperature.