The Countdown to SF₆ Phase-Out: Who Will Power the Grid of the Future?

1.Introduction
In response to climate change, extensive research and development efforts have been undertaken globally to develop various types of SF₆-free gas-insulated switchgear as alternatives to conventional SF₆-based equipment. On the other hand, SF₆-free gas-insulated switchgear has been in service since the late 1960s. By integrally molding live components of the switchgear using solid insulation materials—such as epoxy resin—with dielectric strength significantly higher than that of SF₆, this technology achieves remarkable compactness.

Japanese electric power utilities have operated environmentally friendly, SF₆-free solid-insulated switchgear for over 50 years. These units deliver excellent operational performance, outstanding safety, high efficiency in maintenance and inspection, and proven long-term reliability. Owing to their compact size, SIS units are particularly well suited for installation in buildings and underground spaces—especially in densely built-up urban areas where space is limited.

To date, approximately 6,000 units of SF₆-free gas-insulated switchgear have been installed, primarily serving electric utilities, general industrial facilities, and transportation infrastructure. Among the roughly 3,000 units deployed in utility networks, the rate of major failures causing power outages over the past 50+ years has been less than half that of conventional gas-insulated switchgear (GIS), demonstrating the high reliability of SF₆-free gas-insulated switchgear.

Recently, a number of SF₆-free gas-insulated switchgear units that had been in field operation for 10 to 50 years were retrieved and returned to the factory for evaluation, including assessments of insulation aging and service life. The results indicate an estimated operational lifespan of approximately 60 years.

Furthermore, life cycle assessment (LCA) studies show that SF₆-free gas-insulated switchgear can reduce total greenhouse gas (GHG) emissions—expressed as CO₂ equivalents—to about 65%–70% of those associated with cubicle-type gas-insulated switchgear (C-GIS). SF₆-free gas-insulated switchgear contains no fluorinated gases or any other gases with a 100-year global warming potential (GWP₁₀₀) exceeding 100. Compared with GIS, it has demonstrated comparable or even superior expected service life and reliability. In addition to its compact footprint, it also generates significantly lower CO₂-equivalent greenhouse gas emissions.

Therefore, SF₆-free gas-insulated switchgear represents a viable solution among SF₆-free switching technologies, and its adoption is expected to expand further.
— “Long-Term Operational Experience of SF₆-Free Gas-Insulated Switchgear in Japanese Electric Power Utilities”

2.Interpretation of Domestic and International Policies and Regulations

2.1 International Policies

Sulfur hexafluoride (SF₆) has a global warming potential (GWP) 23,500 times that of carbon dioxide and is listed as one of the six greenhouse gases under the Kyoto Protocol. Developed countries and regions—including the European Union, the United States, and Japan—have implemented stringent policies to restrict SF₆ use:

• European Union: Under the F-Gas Regulation, the EU mandates a phasedown of SF₆ consumption, aiming to reduce its use to one-third of 2014 levels by 2030.

• United States: Several states have enacted regulations to limit SF₆ emissions and actively promote environmentally friendly alternative technologies.

• Japan: The Act on Promotion of Global Warming Countermeasures explicitly requires the reduction of SF₆ usage and emissions.

2.2 Domestic Policies

As the world’s largest market for power equipment, China has in recent years actively promoted the substitution of SF₆:

• "Dual Carbon" Strategy: China has set clear national targets to peak carbon emissions by 2030 and achieve carbon neutrality by 2060. Reducing SF₆ emissions is a critical component of this strategy.

• Industry Standards: State Grid Corporation of China and China Southern Power Grid have issued multiple technical specifications encouraging the adoption of SF₆-free, eco-friendly switchgear.

3. Industry Outlook on SF₆-Free Solutions

As environmental regulations tighten and technology advances, the power industry’s attitude toward SF₆-containing equipment has shifted significantly:

• Phasing Out SF₆:
  SF₆ is not only harmful to the environment but also poses risks of leakage and incurs high maintenance costs. The industry is progressively phasing out conventional SF₆ switchgear.

• Embracing Eco-Friendly Alternatives:
  SF₆-free switchgear—valued for its environmental friendliness, safety, and operational efficiency—is emerging as the new direction for industry development.

4. SF₆ Replacement Approaches and Trends

No. 1 Solid Insulation Technology
Uses solid insulation materials instead of SF₆ gas, eliminating greenhouse gas emissions at the source.

No. 2 Vacuum Interruption Technology
Employs vacuum interrupters to achieve highly efficient and reliable current interruption.

No. 3 Eco-Friendly Gaseous Alternatives
Utilizes environmentally benign insulating media such as dry air or nitrogen in place of SF₆.

5. RockWill Electric——Performance Advantages of the EcoRing Series Switchgear
As an industry-leading power equipment manufacturer, RockWill Electric has always been committed to technological innovation and application. Leveraging strong R&D capabilities and deep market insights, the company has successfully launched the EcoRing Series SF₆-free gas-insulated switchgear.

Feature

• 35kV-Level Maintenance-Free Operation：The hermetic gas chamber (with leak rate ≤ 0.1%/year) and wear-resistant mechanical components eliminate routine maintenance tasks like gas refilling and part replacement. It reduces operation and maintenance (O&M) costs by over 60% compared to traditional switchgear.

• Superior Stable Power Supply Performance：Equipped with vacuum interrupters for arc extinction and high-precision current/voltage transformers, it effectively resists short-circuits, overvoltage, and voltage fluctuations. It maintains a power supply reliability rate of ≥ 99.98% even in harsh environments (e.g., high humidity, dust, or extreme temperatures).

• Eco-Friendly & Safe Gas Insulation：Uses Low-GWP environmental protection gas (compliant with IEC 61730 standards) to avoid greenhouse gas emissions; the fully sealed structure prevents gas leakage and ensures personnel safety. It also has strong corrosion and pollution resistance, suitable for both indoor and outdoor installations.

• Compact Design & Smart Integration：The modular and compact structure saves 40% of installation space compared to air-insulated switchgear, fitting narrow areas like urban underground substations. It supports integration with intelligent monitoring systems to track gas pressure, temperature, and operating status in real time, enabling predictive fault management.

The EcoRing Series SF₆-free gas-insulated switchgear is a truly intrinsically safe product, thanks to its high reliability, full adaptability to diverse operating conditions, and maintenance-free design. It not only delivers outstanding performance but also serves as an ideal replacement for conventional air-insulated switchgear (e.g., KYN61) and SF₆-based CGIS switchgear, offering a more advanced and reliable solution for power systems.