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One of the components of an electrical substation is the circuit breaker. Since more than 50 years, SF₆ (or Sulphur Hexafluoride) has been in use to extinguish the electrical arc that occurs during the circuit breaker switching as this gas has excellent insulating and dielectric properties.

With the accelerating climate change, decarbonizing the electrical grid is a key challenge for the electrical industry. GE is developing SF₆-free equipment to help grid operators to achieve their carbon neutrality goals.


SF₆ is listed at the top of the Kyoto Protocol as one of the gases with a very high global warming potential (GWP). Indeed, SF₆’s GWP is 25,200 higher than CO₂ and if released, it remains more than 3200 years in the atmosphere.

As part of its target to reduce EU’s carbon footprint by 65% before 2035, the EU Commission first encouraged the industry to find ways to look for alternatives to SF₆ in use in electrical equipment. Today, alternatives exist, and the EU Commission supports the move.


GE’s Grid Solutions, together with its partners, will develop a live tank circuit breaker (LTCB) at 245 kilovolts (kV) and 50 kiloamperes that will use GE’s g³ gas instead of SF₆. g³ LTCB will feature the same ratings and same dimensional footprint as the state-of-the-art SF₆ ones, with a drastically reduced environmental impact: more than 99% less gas GWP, comparatively.

Our LIFE SF₆-free HV BREAKER project benefits from the financial support of the EU Commission’s LIFE Programme for the environment and climate action.

Objective 1

Validate the technical viability of the combination of a new gas mixture based on GE’s g³ gas technology and the improved 245 kV/50 kA High Voltage Live Tank Circuit Breaker (HVLTCB) design for temperature down to -30°C

Objective 2

Set-up of a pilot 245 kV/50 kA HV Live Tank Circuit Breaker at Grid Solutions (GE) premises in Villeurbanne (France) to meet transmission system operators’ (TSOs) requirements for HVLTCB, as required before any on-site installation on a HV transmission network

Objective 3

Launch a demonstration at a TSO’s premises to implement an integrated 245 kV/50 kA SF₆-free HVLTCB solution on its transmission network

Objective 4

Integrate 420 kV/50 kA and 550 kV/50 kA technical requirements in the new HVLTCB design in order to ensure a solution fitting the whole 50 Hertz (Hz) high voltage (HV) air-insulated substation (AIS) applications.

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