Energy Efficiency of Data Center Operating Practices: Server Clustering, Powering On/Off, and Bang-Bang Control

Abstract

Data centers today account for up to 3% of all global electricity consumption and produce 200 million metric tons of CO2. Hence, improving energy efficiency is an important operational concern. This article examines common operating practices such as server clustering, powering on/off, and bang–bang control in terms of energy efficiency. Extending the mixed integer programming (MIP) formulation in a previous research study, we introduce new constraints reflecting the operating practices adopted for operational convenience. We develop an algorithmic strategy for constructing energy efficient clusters of servers using two upper bounds on the cluster size. Numerical experiments show that server clustering and bang–bang control do not diminish energy efficiency, and that powering on/off by itself is insuffcient. Our results produce a conclusion that differs from the published literature on data center design and operations.