Belgium: A new EU-backed research initiative is moving high-voltage switchgear closer to full decarbonisation. The LIFE Blue project is developing and validating an emission-free 420 kV AC gas-insulated switchgear (GIS) solution based on clean air insulation and vacuum switching, aiming to demonstrate its technical and economic feasibility under real grid conditions.
Sulphur hexafluoride (SF₆) has long been used in high-voltage GIS because of its strong insulating and arc-quenching properties. However, its extremely high global warming potential and long atmospheric lifetime have driven regulatory pressure to replace it. The EU’s revised F-gas Regulation will restrict the use of F-gases with a global warming potential above one for new switchgear installations above 52 kV from 2028.
Against this background, the LIFE Blue project focuses on replacing SF₆ with a clean air mixture of nitrogen and oxygen combined with vacuum switching technology. The project is funded under the EU LIFE programme and brings together one original equipment manufacturer and five transmission system operators from across Europe, supported by an expert advisory board.
The 420 kV GIS design meets relevant IEC standards for insulation, switching performance, mechanical stability and environmental resistance. A low-power instrument transformer is integrated to support digital substation concepts and reduce material use and cabling requirements.
A pilot installation is planned at the Verbrande Brug substation in Belgium, where an existing SF₆-insulated bay dating from 1989 will be replaced. The pilot will assess gas handling, sealing behaviour, switching performance, measurement accuracy and long-term operation.
Testing to date has confirmed successful performance of key components, including a multi-break vacuum circuit breaker concept adapted from lower voltage applications. Type testing is scheduled for 2026, with pilot operation expected to begin in 2027.
The project reflects a broader industry shift toward F-gas-free switchgear solutions as utilities prepare for tightening regulations and long-term sustainability requirements.
Source: Enlit
