Germany, Mannheim: Hitachi Energy and TenneT Germany have successfully completed on-site acceptance tests of an SF6-free 420 kV gas-insulated switchgear at the Erzhausen substation.
The test marks a key step for high- and extra-high-voltage grid infrastructure, where sulphur hexafluoride, or SF6, has long been used as the standard insulating and arc-quenching gas. Due to its high climate impact, SF6-based technology is facing growing environmental and regulatory pressure.
The validated 420 kV switchgear is part of Hitachi Energy’s EconiQ technology platform. According to the companies, the test confirms that the technology is operationally ready at the highest transmission voltage level under real grid conditions.
The successful validation shows that alternative insulation systems can be used in extra-high-voltage switchgear. For grid operators, this could support future transmission expansion with a lower environmental impact. A key challenge will be moving SF6-free systems from pilot projects into wider grid deployment.
“The successful completion of the on-site tests in Erzhausen is a major milestone for this project and for our grid expansion plans,” said Stefan Bönig of TenneT Germany. “It shows that SF6-free technology can meet the technical requirements at the highest voltage level and supports our long-term goal of building a more sustainable transmission system.”
SF6 is used in sealed, pressurised switchgear systems across transmission and distribution networks. During normal operation, the gas remains largely contained, but emissions can occur through leakage, maintenance, decommissioning or disposal.
SF6 has a global warming potential around 24,300 times higher than CO2, making its replacement important for reducing the environmental impact of switchgear systems.
Source: Renewable Energy Industry
