Energy consumption measurement survey in commercial buildings in Japan - The existence of stand-by electricity

Panel: Panel 4: Sustainable Energy Use in Buildings

Authors:
Chiho Nakagomi, Jyukankyo Research Institute
Akio Tanaka, Jyukankyo Research Institute
Hiroyuki Ohashi, Jyukankyo Research Institute
Hidetoshi Nakagami, Jyukankyo Research Institute

Abstract

Energy conservation in commercial sector plays one of the important roles along with the other sectors in order to meet the Kyoto target. Promotion of energy conservation in commercial buildings requires at first to grasp the present status of their energy consumption. However, few long-term energy measurement surveys in commercial buildings in Japan have been ever conducted, while many energy consumption surveys are based on energy bill.

In this paper, we present results of an actual measurement of energy consumption in commercial buildings, and also analysis of the relation between the end-use energy consumption and several parameters (outdoor temperature, humidity, tenant occupancy rate, etc.) based on the annual measured data on electricity consumption as well as past three years energy consumption reports.

We expressed the air-conditioning and fan energy demand as a function of the outdoor temperature by using least square method. The regression equations whose errors lie between 0.2~5.9% assume high accuracy. This result will contribute to estimate the demand of end-use energy consumption in commercial buildings.

The hourly energy consumption data reveal an interesting fact that 20 kW of power is loaded constantly through the night. This nocturnal electricity demand for unspecified might be largely attributed to the existence of stand-by electricity in office equipment. This fact suggests the potential of energy conservation and necessity of further survey on energy consumption by type of use including stand-by electricity in commercial buildings.