accelerating the replacement of the potent greenhouse gas SF6 in electrical equipment is imperative. Given the differences in technical maturity and applicability among various eco-friendly insulation gases
a phased substitution strategy tailored to equipment type
voltage level
and other key factors is necessary. This paper analyzes the usage of SF6 in electrical equipment in China and evaluates potential alternatives across five dimensions: environmental impact
manufacturing carbon footprint
applicable voltage level
environmental suitability
and biosafety. A stage-by-stage strategy for SF6 substitution with eco-friendly gases is proposed. The total SF6 usage in China’s electrical equipment is approximately 164.21 kt
with 82% used for insulation and 18% for arc quenching. Ten alternative solutions combining SF6
C4F7N
clean air
and vacuum arc quenching technologies are assessed. Based on China’s climate conditions and the distribution of electrical equipment
a staged substitution strategy is proposed for insulation versus arc quenching apparatus
different climate zones
and voltage levels. It is recommended that equipment rated at 220 kV and below be prioritized for retrofitting with vacuum arc quenching and clean air insulation. For equipment above 220 kV
SF6 may be retained for arc quenching in the near term. In warmer regions
insulation equipment should adopt a 9%C4F7N/91% CO2 mixture; in colder regions
clean air is recommended for insulation in 220~550 kV equipment
while SF6/N2 mixtures are suggested for insulation above 550 kV. This strategy is projected to reduce greenhouse gas emissions from electrical equipment by 99%.