Solid Insulated Switchgear 2025: Epoxy, Economics and the End of SF₆
For half a century medium-voltage switchgear meant two choices: air-insulated (AIS) that devours real-estate, or gas-insulated (GIS) that leaks SF₆. Solid insulated switchgear (SIS)—live parts cast in epoxy resin—offers a third path: zero gas, zero pressure, and zero greenhouse liabi