抄録
Due to the increase in its efficiency and the decrease in its cost, photovoltaic (PV) becomes one of promising technologies to produce renewable energy. However, it is well-known that the CO2 emission comes from its manufacturing stages. Recently, the ensemble effect is pointed out, in which the CO2 reduction by deployed PVs is cancelled by the CO2 emission to manufacture new PVs when the growth rate of deployment is so fast. In this study, considering the ensemble effect, we clarify whether the CO2 emission is really reduced by PVs or not so far for each country and the world.
