Discussion on the Life Cycle of Greenhouse Gas Emissions from the 2021 UNECE LCA Report and Korean LCI DB for Electricity Generation

Abstract

Objectives : The greenhouse gas (GHG) emissions of coal, natural gas, wind, solar, hydropower, and nuclear electricity generation mentioned in the United Nations Economic Commission for Europe (UNECE) LCA report were discussed. Korean GHG emissions were calculated from the electricity database (DB) of the Korean national life cycle inventory (LCI), compared with the international average, and then discussed. The aim of this study was to discuss the necessity of updating and internationalizing the national LCI DB.Methods : The GHG emissions from the generation of coal power, natural gas power, wind power, onshore wind power, solar power, and hydropower in the UNECE LCA study were analyzed, and climate change, that is, GHG emissions, among the environmental impact assessment categories was discussed. The GHG emissions per 1 kWh functional unit were calculated from the electricity DB of the Korean national LCI by applying the global warming potential to GHGs.Results and Discussion : The GHG emissions from natural gas (452 g CO<sub>2</sub>-eq./kWh), nuclear (6.3 g CO<sub>2</sub>-eq./kWh), and solar power generation (53 g CO<sub>2</sub>-eq./kWh) presented in the national LCI DB were within the range of results presented in the UNECE LCA report. However, GHG emissions of Korean coal power generation exceeded the UNECE average and highest ranges. The GHG emissions of Korean hard coal and bituminous power generation were 1,351 g CO<sub>2</sub>-eq./kWh and 1,160 g CO<sub>2</sub>-eq./kWh, respectively, which were higher than the highest UNECE value, 1,095 g CO<sub>2</sub> eq./kWh (China). Analysis of the Korean electricity LCI DB for coal power plants showed that bituminous coal-fired power plants that use more brown coal, which is known to be relatively low-quality coal, produce less CO<sub>2</sub> than anthracite coal power plants. In Korean coal-fired power plants, it is necessary to check whether CO<sub>2</sub> generated from processes other than the combustion process is significant.Conclusion : Electricity accounts for the largest portion when calculating national greenhouse gas emissions, therefore, accurate data is necessary. Korea, which is highly dependent on coal-fired power generation for electricity production, should update its electricity LCI DB as soon as possible to increase national competitiveness and use it as a basis for realizing carbon neutrality by 2050.