Europe: The MISSION project, co‑funded by the EU through Horizon Europe, is setting a new standard for sustainable HV technology by demonstrating that SF₆-free solutions are both practical and cost-effective. For decades, HV switchgear relied on sulphur hexafluoride due to its strong insulation properties. However, its environmental impact is severe, with a global warming potential of 24,300 and a lifespan of over 1,000 years.
New EU F-gas rules will ban high-GWP gases in switchgear above 52 kV from 2028 and above 145 kV from 2032, accelerating the move towards cleaner alternatives. Supported by Horizon Europe, MISSION focuses on replacing SF₆ with an 80 % nitrogen and 20 % oxygen mixture across AC and DC systems.
A key development is the 420 kV air-insulated live tank vacuum circuit breaker. Designed to match existing SF₆ units, it enables easy retrofitting while removing around 53 kg of SF₆ per unit. Testing is progressing well, with type tests planned for 2026 and pilot installations in France and Norway later that year.
The project also advances 550 kV DC gas-insulated switchgear, supporting efficient long-distance transmission and offshore integration. Extensive simulations and testing ensure performance under real operating conditions.
MISSION brings together 12 partners from nine countries, including five universities and research institutes, two switchgear manufacturers, four grid operators and one superconducting DC system developer, to validate these technologies and assess future grid needs. Early results show that natural gas mixtures offer reliable performance, simpler handling, and strong environmental benefits.
Overall, the project demonstrates that emission-free HV transmission is achievable, scalable, and aligned with Europe’s net zero ambitions.
Source: Enlit
