Long-term Analysis of Factors Influencing the Dissemination of Residential PV Systems in Japan

Abstract

This paper focuses on residential PV systems in Japan and analyzes their factors of dissemination quantitatively over the years by new and existing houses using annual prefectural data. A method is proposed based on regression analysis and analysis of factors using results of the regression analysis. The regression analysis is applied annually to the correlation between payback period and annual installation rate in the 47 prefectures by new and existing houses. By using the estimated annual regression lines, annual increment of installation rate is separated into two parts. One is effect of economic factors, which can be calculated with regression line for the prior year and payback period in the current year, and the rest is effect of non-economic factors.
Based on the results of the analysis, non-economic effects were dominant in the early years especially for existing houses. However, recently the economic effects have become dominant in both new and existing houses. From FY2001 to FY2003, factors of dissemination are different in new and existing houses reflecting housing market. Non-economic factors are mainly based on high environment consciousness and many other occasional factors, such as the booming due to a subsidy and Feed-in-Tariff, sales promotion by house and PV cell manufacturers.