Study on the Diffusion of NGVs in Japan and Other Nations Using the Bass Model

In this study, the Bass Model was utilized to estimate the future diffusion of natural gas vehicles (NGVs), in Japan and other countries. The parameters contained in the model, namely, coefficient of innovation (p), coefficient of imitation (r), and the potential market (N), were extracted from the trend as indicated by the actual diffusion curve up to 2014, after which the ultimate diffusion number was calculated based mainly on these parameters. Firstly, three scenarios were established to analyze the future diffusion of NGVs in Japan, with the highest outcome being 8.5 million, accounting for 14 % of the total vehicles. Secondly, as a feasibility study, the Bass Model was utilized to examine twelve countries where NGVs are popularized. The actual diffusion curve pertaining to Iran, Argentina, India, Brazil, Italy, Columbia, Thailand, Ukraine, and Bolivia could ideally fit the Bass Model curve, while the fit was poor for China, Pakistan, and the United States. The reasons for the poor fit were then explained. Finally, the conditions and requirements to facilitate the highest diffusion number in Japan were discussed.