Exploring the Demand Response Potential of Liquid-Cooled Data Centers

Due to the rapidly increasing electricity consumption of data center (DC), the participation of DCs in power demand response (DR) has garnered significant attention. Existing studies have predominantly focused on the dispatchable computing loads while relatively neglected the flexibility of thermal management systems of DCs. Notably, cooling systems account for approximately 30-40% of total DC energy consumption, and the cooling modes are evolving rapidly in pursuit of higher energy efficiency, among which the liquid cooling systems (LCSs) are regarded as the most promising technology worldwide. The multi-stage efficient heat exchange capability of LCS makes the flexibility of DC power consumption more pronounced, which has not yet been well characterized. In this paper, the electrical-thermal coupled characteristics of a typical Liquid-cooled DC (LCDC) are investigated and its potential to participate in power system DR is assessed for the first time. Fundamentally, the entire electric-thermal conversion and heat transfer process during LCDC operation are fully modelled, considering various components. Subsequently, a coordinated DR control strategy for computing server and LCS is formulated, considering constraints such as server temperature and Quality of Service (QoS). Furthermore, an index system is established to quantify the dynamic DR capability of the LCDC. Finally, case studies illustrate the DR potential of an LCDC is considerable, providing an average electrical power reduction of nearly 30% for a duration of about 20min under the set constraints. The numerical results clearly demonstrate the mutual constraints among LCDC DR indexes, such as response capacity, duration, and power rebound.