Vol.3 No.3 2010

Research paper−189−Synthesiology - English edition Vol.3 No.3 pp.189-196 (Dec. 2010) reused in greenhouse farming, is an effective use of energy that is also economically feasible.2 Limit in achieving efficiency by a single datacenterThe energy flow and energy consumption configuration in a typical datacenter is shown in Fig. 1 and Table 1. The model considered here is a datacenter with maximum capacity of 1,000 racks (actual operation rate 85 %) and maximum power supply at 6 kW/rack (average 4.2 kW/rack). When the power consumption of the entire datacenter is simulated, and the simulated figure is multiplied with an emission coefficient published by electricity companiesNote 2), the CO2 emissions are as shown in Table 2.One of the effective methods for improving energy efficiency, when considering power consumption of air conditionings at the datacenter, is to raise the air conditioning efficiency by constructing the datacenter in a cold climate area. For example, comparing Sapporo and Tokyo where there are 1 IntroductionInformation and communication technology (ICT) has greatly contributed to the reduction of CO2 emissions through efficient energy use and conservation by avoiding redundancy in economic activities and by enabling efficient transportation and its alternatives. However, power consumption in offices and homes is increasing due to the wide uptake of ICT, and as a result, it has become one of the main factors that push up CO2 emissions in Japan. If this increase continues, ICT power consumption in 2025 will be 5.2 times more than 2006, dominating 25 % of the total power generated in JapanNote 1). The reduction of power consumption in the ICT field is a major issue.Particularly, datacenters equipped with multiple servers consume a large amount of electric power, and power consumption increases every year. From the perspective of preventing global warming, energy consumption and reduction of CO2 emissions are becoming major issues. Therefore, the Japanese datacenter industry is working to introduce efficient servers, air conditioners, and power supply facilities. However, the potential of efforts to increase energy efficiency for a single datacenter alone is limited, and a design approach that looks at the essence of the issue is in demand.Therefore, as a new design approach, we propose the “strategic system design” in which the systems of multiple companies are combined. As an example of the strategic system design, we shall explain that a composite system, in which low-temperature waste heat from a datacenter is - Reduction of CO2 emissions at a datacenter by reusing emitted heat for agriculture -Jiro Fukuda1* and Taketoshi Hibiya21. Graduate School of System Design and Management, Keio University / Mitsubishi Research Institute, Inc. 2-3-6 Otemachi, Chiyoda-ku 100-8141, Japan *E-mail : , 2. Graduate School of System Design and Management, Keio University 4-1-1 Hiyoshi, Kohoku-ku, Yokohama 223-8256, Japan Original manuscript received January 15, 2010, Revisions received May 31, 2010, Accepted June 15, 2010 Datacenters are important infrastructures of information and communication technology (ICT). Reducing electric-power consumption and the CO2 emissions at the centers are urgent issues from the viewpoint of global environmental concerns. Improvement of efficiency within a single datacenter, however, cannot assure significant reduction of CO2 emissions. Hence we propose the concept of “strategic system design”, which optimizes system design by combining different stake-holders not only from the viewpoint of the “physical system” but also from that of the “value system”. As an example, a system in which greenhouse cultivation farms reuse emitted heat at datacenters was considered from both the physical side and the value side. The complex system designed by such a strategic system design idea was found to be effective in reducing CO2 emissions compared with a single isolated system, and was clarified to be an excellent value system.An optimum design method utilizing a strategic system design conceptKeywords : Datacenter, global environment, system design, emitted heat, greenhouse business[Translation from Synthesiology, Vol.3, No.3, p.190-196 (2010)]UserCommunicationcompanyDatacenter companyElectricpowercompanyPowerplantPowersupplyUninterruptiblepower deviceServerEmergencygeneratorNetworkservicePCWasteheatAirconditioningdeviceFig. 1 Energy flow of the datacenter


page 4