Eco-friendly Insulation Gases in High Voltage Applications

The urgent need to curb greenhouse-gas emissions has driven concerted research into alternatives to sulphur hexafluoride (SF6), a long-standing dielectric medium in high-voltage equipment. While SF6 offers unrivalled dielectric strength and arc-quenching capabilities, its extremely high global warming potential (GWP) and atmospheric lifetime render it unsustainable. Recent efforts focus on novel molecules and tailored gas mixtures that combine low GWP, robust insulation performance and operational compatibility with existing switchgear. Leading candidates include perfluorinated ketones, fluoronitriles and hydrofluoroolefins mixed with buffer gases such as CO2, N2 or O2 to optimise breakdown voltage and suppress undesirable decomposition. Complementary life-cycle assessments evaluate cradle-to-gate impacts, while dielectric tests probe partial-discharge behaviour under uniform and non-uniform fields. Attention to decomposition pathways informs safety and maintenance protocols. Collectively, these advances promise to reconcile stringent environmental regulations with the reliability demands of modern power networks, facilitating a progressive transition toward low-carbon high-voltage infrastructure.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Eco-friendly Insulation Gases in High Voltage Applications publication trend

The graph below shows the total number of articles in eco-friendly insulation gases in high voltage applications across all publications each year (not limited to Nature Index journals).

Technical terms

Sulphur hexafluoride (SF6): A synthetic gas with exceptional dielectric and arc-quenching properties but extremely high global warming potential and atmospheric lifetime.

Global warming potential (GWP): A metric for comparing the heat-trapping capacity of a greenhouse gas relative to CO2 over a specified timescale, typically 100 years.

Dielectric strength: The maximum electric field that a gas or insulating medium can withstand without breakdown or conductive failure.

Partial discharge (PD): Localised electrical discharges that occur within voids or along interfaces in an insulating medium, often preceding full breakdown.

Perfluorinated ketone: A class of organic molecules in which all hydrogen atoms are replaced by fluorine, offering high insulation performance and low GWP when used as gaseous dielectrics.

References

1. Cradle-to-gate life cycle assessment comparison between two switchgear designs: Eliminating SF6 gas under European legislation. Environmental Impact Assessment Review (2025).
2. Recent Advances in the Quest for a New Insulation Gas with a Low Impact on the Environment to Replace Sulfur Hexafluoride (SF6) Gas in High-Voltage Power Network Applications. Energies (2017).
3. Experimental study on the partial discharge and AC breakdown properties of C4F7N/CO2 mixture. High Voltage (2019).