China's power grid emits 1.8 million tonnes of sulfur hexafluoride in 2023.

China’s power grid emitted an estimated 1.8 million metric tonnes of sulfur hexafluoride (SF6) in 2023, making it the world’s largest source of the gas, according to a report released by the Ministry of Ecology and Environment on Tuesday. The figure eclipses the combined output of the United States and Europe and adds a new twist to China’s climate narrative as the country touts its rapid expansion of wind and solar capacity.

SF6 is a synthetic compound used as an insulating and arc‑quenching agent in high‑voltage switchgear, transformers and circuit breakers. Its global warming potential is about 23,500 times that of carbon dioxide over a 100‑year horizon, meaning a single kilogram of SF6 traps as much heat as 23.5 tonnes of CO₂. The gas is chemically inert, so once released it stays in the atmosphere for centuries. China’s grid, now the world’s biggest, relies on millions of pieces of equipment that contain the gas, and rapid upgrades to handle renewable power have increased the demand for new switchgear.

The report shows a 12 percent rise in SF6 emissions from 2022, despite a 15 percent drop in coal‑generated electricity over the same period. Environmental NGOs say the surge reflects a “hidden carbon cost” of the clean‑energy transition. Beijing has pledged to curb SF6 releases, citing the 2021 amendment to its national emissions trading scheme that now includes the gas. Industry groups argue that alternatives such as fluoronitrile (CF3ON) and vacuum technology are not yet ready for large‑scale deployment, and that a sudden switch could jeopardise grid reliability.

Experts say the next steps will hinge on tighter regulation and faster adoption of low‑SF6 technologies. The government plans to tighten leak‑detection standards and to incentivise retrofits of existing equipment with newer, less harmful designs. International climate negotiators are watching China’s response, as the country’s ability to control SF6 will influence the feasibility of meeting the 2030 carbon‑neutrality target pledged at the recent UN climate summit. Reducing SF6 could shave a few hundred million tonnes of CO₂‑equivalent from the global budget, a modest but symbolically important win in the fight against warming.