TOKYO: Hitachi Ltd. has announced that it has secured an order from Chubu Electric Power Grid to supply the world’s first 550 kilovolt (kV) gas-insulated switchgear (GIS) in which the entire equipment is free from sulfur hexafluoride (SF₆). The project will utilize Hitachi Energy’s advanced EconiQ® 550 kV GIS, marking a significant milestone in the global transition toward sustainable power infrastructure.
Gas-insulated switchgear houses all electrical components within sealed gas-insulated compartments, reducing the physical footprint of substations while protecting equipment from storms and other environmental interference. The newly developed EconiQ technology represents a major breakthrough, as it eliminates the use of SF₆—one of the most potent greenhouse gases used in power systems.
According to Hitachi Energy, the EconiQ 550 kV GIS reduces CO₂-equivalent emissions from insulating gases by up to 99 percent compared with conventional SF₆-based equipment. By deploying this technology, Chubu Electric Power Grid aims to strengthen the sustainability and resilience of Japan’s transmission network while supporting national decarbonization goals.
For decades, SF₆ has been widely used in high-voltage power equipment because of its excellent insulation and switching capabilities. However, the gas has a global warming potential approximately 24,300 times higher than CO₂ and can remain in the atmosphere for over 1,000 years if released. In response, many countries are introducing regulations to phase out SF₆-based equipment, although Japan has not yet implemented formal restrictions.
Electricity demand in Japan is rising rapidly due to increased electrification and the expansion of data centers, making it critical to reinforce transmission infrastructure while reducing greenhouse gas emissions. SF₆-free switchgear technologies such as the EconiQ portfolio offer a practical solution by combining proven reliability and compact design with a dramatically lower environmental footprint.
In 2024, Chubu Electric Power Grid announced its policy to gradually introduce SF₆-free equipment across different voltage levels. The company had already decided to adopt SF₆-free GIS for voltages up to 77 kV and SF₆-free circuit breakers rated at 275 kV and above. The latest decision to deploy SF₆-free 550 kV GIS reflects the utility’s commitment to accelerating progress toward carbon neutrality.
Launched in 2021, Hitachi Energy’s EconiQ high-voltage portfolio is designed to support the global power industry in transitioning to environmentally sustainable grid technologies by replacing SF₆ with eco-efficient alternatives while maintaining the same performance, safety, and reliability standards.
