An Eskom-authored technical paper has underscored the critical importance of laboratory testing, diagnostics and handling protocols as utilities seek to replace sulphur hexafluoride SF6 with lower-emissions alternatives in high-voltage electrical equipment.
Presented during the CIGRE Southern Africa Regional Conference in Pretoria in October 2025, the paper reviews international testing methodologies used to assess a range of SF6 substitute gases against the backdrop of growing regulatory and environmental pressure to phase down the use of SF6. The gas has a global warming potential around 23 500 times that of CO2 and an atmospheric lifetime exceeding 3 000 years, making it one of the most potent greenhouse gases still widely used in power systems.
Authored by Vusumuzi Sibeko of Eskom, the review examines alternatives including g gas mixtures CO2/C4F7N, C4F7N fluoronitriles, C5F10O fluoroketones, CF3I, CO2 and hydrofluoroolefins HFOs. While many of these gases offer dramatically lower global warming potential than SF6, the paper states their chemical behaviour under electrical stress introduces new operational and safety risks that must be carefully managed.
