China’s first 500 kV power plant project using an eco-friendly gas insulation technology has been successfully commissioned at the Zhejiang Beilun Power Plant, owned by the State Energy Group. The project integrates 500 kV three-phase composite bushings and branch bus ducts using perfluoroisobutyronitrile (C4F7N) as a replacement for sulfur hexafluoride (SF6). This significantly reduces the carbon footprint of high-voltage equipment and provides a replicable model for the power sector’s transition to greener technologies.
Quanzhou Yuji Advanced Materials supplied the C4F7N gas for the project, delivering comprehensive solutions including green manufacturing, precision gas blending, analytical testing, and product delivery, ensuring stable product performance and reliable grid operation.
SF6, historically used in GIS, GIL, and circuit breakers, has a global warming potential (GWP) of 22,800 and is restricted under global climate agreements. In response to pressure to reduce high-GWP emissions, countries like China, the U.S., and the EU have issued policies to phase down SF6, accelerating the adoption of alternative insulating gases.
Zhejiang Beilun Power Plant, operational since 1989 and a major power supplier to the Yangtze River Delta, has initiated a program to replace SF6 with C4F7N to support China’s carbon-peaking and carbon-neutrality goals.
C4F7N offers clear benefits: its decomposition products are less hazardous, reducing risks for maintenance personnel; it eliminates environmental concerns associated with SF6 leakage; and it has a liquefaction temperature of –4.7°C with no ozone-depletion concerns. The project is expected to reduce CO₂ emissions by approximately 85 tonnes—equivalent to the carbon sequestration of around 5,000 mature trees—supporting both environmental and operational objectives.
This successful deployment of 500 kV eco-friendly insulation technology represents a significant step forward in low-carbon power equipment and provides valuable insights for future industry and international standardization efforts.
As one of the first companies globally to develop C4F7N, Quanzhou Yuji has established a comprehensive life-cycle management system covering manufacturing, blending, recycling, purification, and analytical testing. Yuji’s products are used in medium- and high-voltage eco-friendly electrical equipment worldwide, with several Global Fortune 500 companies among its customers.
Yugi continues to drive the replacement of high-GWP SF6, addressing key technical challenges in the industry and supporting the upgrade of green electrical-equipment technologies.
In 2024, at the State Grid Corporation of China’s New-Type Power System Industrial Chain Collaboration Conference, Quanzhou Yuji and the Electric Power Research Institute of China formed the Low-Carbon and Green Power Equipment R&D Integration Consortium, strengthening cooperation on green switchgear technologies and supporting the high-quality development of China’s next-generation power system.
