Spatio-Temporal Reallocation Method for Energy Management in Edge Data Centers

Edge data centers (EDCs) have been widely developed recently to supply delay-sensitive computing services, which impose prohibitively increasing electricity costs for EDC operators. This paper presents a new spatiotemporal reallocation (STR) method for energy management in EDCs. This method uses spare resources, including servers and energy storage systems (ESSs) within EDCs to reduce energy costs based on both spatial and temporal features of spare resources. This solution: 1) reallocates flexible workload between EDCs within one cluster; and 2) coordinates the electricity load of data processing, ESSs and distributed energy resources (DERs) within one EDC cluster to gain benefits from flexible electricity tariffs. In addition, this paper for the first time develops a Bit-Watt transformation to simplify the STR method and represent the relationship between data workload and electricity consumption of EDCs. Case studies justifying the developed STR method delivers satisfying cost reductions with robustness. The STR method fully utilized both spatial and temporal features of spare resources in EDCs to gain benefits from 1) varying electricity tariffs, and 2) maximumly consuming DER generation.