Understanding regional energy consumption patterns in Japanese households through factor analysis

Abstract

A recent survey conducted by the Ministry of Environment in Japan revealed significant disparities in energy consumption between urban and rural regions. Since 2017, data have been collected annually from 13,000 households across ten regions under varying climatic conditions. This study analysed regional energy use by conducting factor analysis using a covariance structure, a method rarely employed in Japan. The analysis identified five to seven key factors that collectively accounted for 50–56% of the observed variance in energy use. In all regions, "lifestyle" (e.g. city type, household size) emerged as the predominant factor, followed by "standard of living" (e.g. building structure, floor area). These results are consistent with those reported previously. The occupation of compact apartments has been demonstrated to engender a reduction in energy consumption, thus representing a low-carbon model lifestyle. The third factor exhibited a regional discrepancy: in cold climates, the heating and lighting measures that contributed to the evaluation of building performance were significant, whereas in non-cold regions, indoor activity schedules, such as cooking times on weekdays or holidays, exerted a greater influence. This study provides an accurate approach to the issue of decarbonised residential CO₂ emissions in cold and non-cold climates. It is imperative to acknowledge that the approach adopted is not a simulation but rather a real-world investigation. The concept of a sustainable lifestyle, as evidenced by shared living, minimal car use, and efficient cooking hours in dense housing, has been identified as a key factor in decarbonisation. This approach, which has been modelled as an ideal sustainable lifestyle for developed countries, such as Japan, is considered a significant step towards achieving environmental sustainability.