Mitigating Sulfur Hexafluoride (SF 6 ) Emission from Electrical Equipment in China

Sulfur hexafluoride (SF 6 ) is a powerful greenhouse gas with high global warming potential. Future growth in SF 6 use will be driven mainly by increasing demand for electricity and associated infrastructure in developing countries. In relation to electrical equipment, China currently produces the largest proportion of SF 6 emissions. Because of the long lifetimes of electrical equipment, SF 6 emissions are substantially different from its consumption, which has been used as an inaccurate proxy for emission estimations, i.e., the so-called “delayed emission effect.” This study established a model to estimate SF 6 emissions by considering the delay through equipment survival, retirement curve, and equipment life cycles. Three scenarios were established to model the potential for mitigation of SF 6 emissions from electrical equipment. The results showed considerable delayed effects in SF 6 emissions associated with electrical equipment. By 2050, the cumulative delayed emission was projected to be 50–249 kt under the different scenarios, which would be 1.2–6.0 GtCO 2 e. Therefore, replacing emissions with consumption could overestimate actual short-term emissions by 1–2 times. Although electrification in end-use sectors and high penetration of renewables in generation could lower global emissions substantially, SF 6 emissions by 2050 could still increase by 15 kt (i.e., 0.36 GtCO 2 e) if mitigation measures are not adopted. Thus, a low-carbon electricity roadmap should be complemented by careful management of electrical equipment. The potential for mitigation of SF 6 emissions could be realized through demand-side management to reduce electricity demand and through technological improvements on the supply side to reduce leakage and increase recovery.