To use or not to use, that is the question: Income and substitution effects in the feed-in tariff system for solar-generated electricity

Feed-in tariff (FIT) is an important worldwide initiative to encourage renewable electricity technologies. Under the Japanese FIT system, households with solar panels decide the amount of both self-consumption and sales to the power company. By analyzing the household self-consumption and sales behaviors of solar-generated electricity obtained from the Ministry of the Environment of Japan, we examine (1) whether the rate of increase in electricity sales by households is higher or lower than the rate of increase in solar power generation and (2) whether self-consumption and sales behaviors of solar-generated electricity differ among households with different sales prices. The results show that the rate of increase in electricity sales is lower than that in solar electricity generation. This suggests that households increase their self-consumption as solar power generation increases. However, as the rate of increase in self-consumption is relatively low, solar-generated electricity is considered as a necessary good. Furthermore, we find that higher sales prices induce households to reduce their self-consumption and increase solar electricity sales to power companies.