Life-Cycle Carbon Emission Calculation and Economic Analysis of Zero-Carbon Buildings: A Case Study in China

To explore the life-cycle carbon emission characteristics of zero-carbon buildings and the economic feasibility of carbon reduction strategies, this study takes the Life Cycle Assessment (LCA) method as the core and constructs a full life-cycle carbon emission accounting system for buildings covering building material production, transportation, construction, operation and demolition in accordance with the standards. Taking the Jinan Zero-Carbon Operation Center Project as a case, this paper systematically calculates its carbon emissions at all stages of the life cycle, identifies the key carbon emission stages and core influencing factors, and comparatively analyzes the economic efficiency of two carbon offset strategies, namely increasing photovoltaic power generation and purchasing green electricity, for the two goals of zero carbon in the operation stage and zero carbon in the full life cycle by using the equivalent annual cost (EAC) method. The results show that the total life-cycle carbon emissions of the case project reach 149,974.04 tCO2e, with the operation stage and building material production stage being the core carbon emission stages, accounting for 75.50% and 24.19% respectively, while the carbon emissions in the transportation, construction and demolition stages account for a negligible proportion. The economic analysis indicates that although the increase in photovoltaic power generation systems involves a high initial investment, its equivalent annual cost is significantly lower than that of the green electricity purchase strategy. Comparative analysis using equivalent annual costs shows that adding a photovoltaic system achieves equivalent annual costs of $206,589.58 and $273,630.84 for operation stage and life-cycle zero-carbon targets, respectively. In contrast, purchasing green power certificates annually to achieve the same goals incurs equivalent annual costs of $316,223.13 and $317,096.45, representing annual savings of 34.67% and 13.71%. The carbon emission accounting method constructed in this study can provide a reference for the life-cycle carbon quantification of zero-carbon buildings, and the conclusions on the economic efficiency of carbon reduction strategies can serve as an economic decision-making basis for the planning, design and carbon reduction scheme selection of zero-carbon buildings.