Data Centers Revisited: Assessment of the Energy Impact of Retrofits and Technology Trends in a High-Density Computing Facility

Abstract

As information and communications technology matures, the nature of the infrastructure that supports it evolves and specializes. While the telephone infrastructure had been built as a network with central offices acting as hubs, the information and communications technology maintains a similar structure, but instead, has hubs of specialized Internet data centers which house the routers and servers. This paper updates one of the first studies to document the electricity consumption and power distribution within an Internet data center. For this study, electricity billing data, metering data, and facility floor space allocation data were used to calculate computer room, total computer room, and building power densities for July 2002. The results of this 2002 study indicate that although the data center had expanded its operations by roughly 33% from the previous year and increased the electricity demand associated with the computer equipment by 55%, the total computer room power density (which includes cooling and auxiliary equipment) remained the same as the previous year at 355 W/m2. The facility’s efforts to improve energy efficiency offset the energy demand from an increased, electrically active, computer room area. The energy-efficiency measures included better optimization of power distribution units, power management modules, computer room air-conditioning units, alterations to operating conditions, facilitywide reductions in lighting, and improved facility controls. A key recommendation is to expand this research to address the need to develop metrics to capture the energy efficiency of the data network throughput.