Carbon Footprint Analysis of Distribution Network Transformers Based on Life Cycle Assessment

Transformers in the distribution network must have their carbon emissions analyzed in order to meet the “double carbon” goal. Using an oil-immersed distribution transformer as the research object, this paper develops a “cradle-to-grave” carbon accounting model. A life cycle assessment (LCA)-based methodology is proposed to account for carbon emissions and total energy demand over the full life cycle and further analyze the carbon emissions within each stage. A case study is presented using data from a 200 kVA transformer manufactured by a transformer plant in Xinjiang. According to the data, there are 112.18 t of carbon emissions and 798.21 GJ of total energy consumed. Distribution network transformers have carbon emissions of 282 kg, 782 kg, 122.96 kg, 11,079.64 kg, and −88.6 kg throughout the manufacture and manufacturing stage, transportation stage, construction and installation stage, operation stage, and waste recycling stage, respectively. There are 4.12 GJ, 9.06 GJ, 1.34 GJ, 785.97 GJ, and −0.28 GJ in total energy requirements. According to the study, which covered 99.03% of the entire life cycle, the operation stage had the largest percentage of carbon emissions. In addition to streamlining the production process and using more energy-efficient equipment, the waste recovery stage successfully decreased the environmental impact of carbon emissions. Sensitivity analysis shows that the silicon steel sheet and transformer oil has a significant impact on the carbon emissions of distribution network transformers during the life cycle, and the higher the grade of silicon steel sheet, the lower the carbon emissions, and the synthetic ester transformer oil has the most comprehensive performance and the lowest carbon emissions.