The use of dye-sensitized solar cells (DSC) with zinc oxide as electrodes is expected to contribute to a CO2 emission-reduction. In this study we examined the CO2 emission-reduction effect by using Life Cycle Assessment (LCA). The Life Cycle Inventory (LCI) was estimated with the LCA software “AIST-LCA ver.4”. LCI was applied to predict the CO2 emission per unit of generated electricity for several potential technical developments of DSC. And the CO2 pay-back time for such solar cells based on conventional power generation systems in Japan was investigated, compared with those for polysilicon solar cells. In addition, according to several solar cell installation scenarios, the installation area and the number of years required by DSC to exceed the polysilicon solar cell in the amount of CO2 reduction were estimated. It was confirmed that DSC technologies are potentially capable of exceeding the polysilicon solar cell in the level of CO2 reduction. The LCI results have lead to an understanding of the differences and factors that influence them. This study offers many important suggestions that will be helpful in making decisions about future research and development into DSC.
