Alstom has unveiled two high-voltage applications using green gas for grid (g3), a gas mixture that can replace sulfur hexafluoride (SF6) for high voltage air-insulated or gas-insulated switchgear applications.Alstom green gas for grid

The company is hailing the gas as a “revolutionary, environmentally-sound solution”.

SF6 is a potent greenhouse gas commonly used as an electrical insulator and is top of the list of six gasses targeted by the 1997 Kyoto Protocol to reduce greenhouse gas emissions worldwide. In August last year Alstom claimed a world first by offering the electrical industry “a technically and economically viable alternative to SF6”.

The first application is a pilot project for a 420 kV g3-insulated busbar for the UK’s National Grid. The trial is of a 420 kV g3-insulated busbar for use at temperatures as low as -25°C. The 300 metre-long line will be located in the southeast of the UK and will be commissioned by mid-2016.

The second application is a 245 kV current transformer type SKF using g3. This high voltage equipment for outdoor applications uses g3 as an insulation medium, with the capability of reaching temperatures as low as -30°C. The current transformer protects substations by providing current measurements used for metering.

Philippe Ponchon, vice-president of product marketing at Alstom Grid, said: “After having launched g3 technology less than one year ago, it is a great achievement to present the first g3-enabled high-voltage equipment and be selected by one of our long-standing customers to supply a revolutionary, environmentally-sound solution.”