A Model for the Evaluation of Potential Energy Conservation of Data Center Focusing on the Air Conditioning Options in Japan

Abstract

The importance of carbon emission reduction is now broadly understood. After the gigantic earthquake on March, 11, 2011, the first priority issue for Japan is the recovery of the society and economy. However, most of the energy conservation options for the global warming mitigation are applicable under the energy constraints. Until today, the impacts of information and communication (ICT) industry have not been well addressed. In Japan, Ministry of Internal Affairs and Communications(MIC) has assessed that the power consumption for the air-conditioning of data centre (DC) indicates 17% of total power demand for ICT. In this study, we develop an optimization model considering the temperature and humidity conditions for DC with 2000 racks in Tokyo and Sapporo including - Cogeneration systems - LNG vaporizer to utilize the evaporating heat - Photovoltaic cell (PV) - Ambient air intake - Turbo refrigerator - Humidifier The results show that 23.9% and 11.9% of CO2 emission could be reduced by introducing photovoltaic cells and humidifier in Tokyo and Sapporo, respectively. The ambient air is largely utilized in Tokyo except for summer while it is not mainly utilized in Sapporo due to the low humidity. Thus, humidifier in Sapporo contributes to reducing CO2 emission in Sapporo. Key Word: data centre, energy conservation, ambient air, LNG vaporizer, humidity control