Abstract
This paper intends to develop a new model for estimating the dissemination curves of the solar water heater and PV, both of which have been calculated on a nationwide basis and for each prefecture. This model is based on public research that evaluated the purchasing eagerness of this equipment based on the actual numbers of dissemination and actual diffusion rates. The newly established model of the solar water heater based on the actual dissemination of three successive types of this equipment is recognized as sufficiently reliable, for its estimation is close to the actual trend. This equipment has also been spreading by word-of-mouth through recognizing that there is an inverse proportion between the dissemination numbers of the solar water heater and the population density of the areas. The newly established PV model estimates that 5.7 millions units will be accumulated by 2020, which is quite close to the deployment scenario set by the government of Japan. However, the correlation between word-of-mouth advertising and PV dissemination is not clearly recognized at this early stage of deployment.
