Renewable energy generation is zero emission technology. However, CO2 emission of renewable energy generation plants is emitted from construction stage. We have been conducted analysis of CO2 emission on construction of renewable energy generation apparatus per generated power. Now, the share of renewable power generation is expected to increase towards CO2 emission reduction targets. In the near future, renewable power plants will be manufactured using electricity generated from renewable energy sources, so CO2 emissions per unit of electricity generated will be lower than present levels. In this study, renewable energy power plants calculated the potential for CO2 emission reduction per generated power using LCA. We used scenarios of 2030 (30% decreased by METI) and 2050 (80% decreased by RITE) in our calculations. Electricity ratio per total CO2 emission of PV, wind power, wave power, tidal power generation, and ocean thermal energy conversion is calculated as 32%, 21%, 20%, 21% and 14%. CO2 emissions reductions per electricity generated from renewable energy generation averaged 6% in 2030 and 17% in 2050.
