Household energy consumption pattern changes in an aging society: the case of Japan between 1989 and 2014 in retrospect

This study examines how population aging affects household energy consumption, first presenting a theoretical framework to assess three effects of population aging on household energy consumption: the pure aging effect, the cohort effect, and the family structure effect. An empirical model is constructed to investigate these three effects based on Japanese households' micro-level energy consumption data from 1989 to 2014. Elderly people tend to secure physical comfort at home in summer and winter, resulting in increased energy consumption, known as the pure aging effect. Our analysis of this effect indicates that household energy consumption increased by about 12% from 1995 to 2015. The diverse energy use patterns of different generations associated with lifestyle preferences are referred to as the cohort effect. A less intensive energy consumption pattern is identified for cohorts of younger generations, confirming our hypothesis. Although economies of scale in household energy consumption are present, the size of Japanese households has decreased in the last several decades, which is called the family structure effect. The family structure effect is also confirmed. Household energy consumption increased by about 16.6% from 1990 to 2015. These results strongly suggest a substantial impact of population aging on household energy consumption in the case of Japan.