Shaping the new standards for SF₆-free switchgear

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Shaping the new standards for SF₆-free switchgear

In 1907, Charles Proteus Steinmetz (you can call him by his nicknames - "Forger of Thunderbolts" or "The Wizard of Schenectady"), one of the pioneers of electrical engineering, warned that as the power grid expanded, engineers would need to standardize equipment to ensure safety and reliability¹. Fast forward to over a century later, we face a similar challenge – this time with insulating gases used in high-voltage switchgear. For decades, sulfur hexafluoride (SF₆) has been the industry standard due to its excellent insulation properties. However, SF₆ is also the most potent greenhouse gas known to humanity, with a global warming potential 24,300 times that of CO₂.

Now, as the power industry transitions to eco-efficient SF₆-free alternatives, standardization is once again crucial. Without clear guidelines and a common framework, interoperability, safety, and long-term reliability remain uncertain. This blog explores why SF₆-free gases need to be standardized and how industry collaboration is shaping the future of switchgear technology.

Curious to learn more? I break it all down in the latest Power Pulse episode “Rewriting the rulebook: Why SF₆-free tech needs new rules.”

The importance of standardization

Over the last decade, major manufacturers have focused on finding viable SF₆-free alternatives. Although different institutions and companies explored various solutions in the early stages, now, SF₆-free switchgear is transitioning from an experimental phase to a standard procurement choice in certain regions. Governments and utility companies are prioritizing SF₆-free equipment, making standardization crucial to ensure interoperability, safety, and long-term sustainability.

Standardization does not mean forcing all manufacturers to use the same design. Rather, it provides a common framework for testing, performance, safety, and long-term serviceability. High-voltage switchgear operates for 40 to 50 years, necessitating a robust ecosystem of support, including training, maintenance, and component availability.

Some key reasons why SF₆-free gases need to be standardized include:

The process of standardization

Setting new standards is a lengthy process, typically taking over a decade. The standardization process follows a structured approach:

1. Pre-standardization phase: Companies and academic institutions publish technical findings. Organizations like CIGRE (Conseil International des Grands Réseaux Electriques) compile state-of-the-art knowledge in technical brochures.
2. Standardization phase: Regulatory bodies such as the International Electrotechnical Commission (IEC) and the Institute of Electrical and Electronics Engineers (IEEE) define global standards.

Each phase can take around five years, but the process can be extended depending on the complexity of the technology.

Of course, manufacturers would benefit from a single, global SF₆-free standard, but the reality is more complex. Electricity grids operate on different frequencies—for example, 50 Hz in Europe and 60 Hz in North America—creating unique challenges. Additionally, regional regulatory requirements vary, leading to a diverse standardization landscape.

Despite these challenges, most standards today have been updated to accommodate SF₆-free alternatives. The key is to focus on standardizing the functional requirements rather than the specific design.

Standardization of SF₆-free equipment

The transition to SF₆-free equipment called for an update of gas handling procedures to ensure compatibility and safety with alternative gases. Hitachi Energy made significant contributions to the development of regulations by co-authoring the C4-FN mixtures for high-voltage equipment handbook. The handbook serves as a guide for the worldwide application of eco-efficient gas mixtures containing C4-FN and addresses key technical questions from customers and experts in the high-voltage community.

Currently, several standardization resources are available to support the industry–wide transition to SF₆-free switchgear. New and adapted IEC standards for SF₆ alternatives (IEC 62271-4) focus on gas handling and cover the relevant aspects of the eco-efficient gas mixtures used in EconiQ® equipment.

The role of industry collaboration

Industry collaboration is vital for effective standardization. Organizations like CIGRE bring together manufacturers, grid operators, utilities, gas suppliers, academia, and consultants to share knowledge. These working groups ensure that standards are practical, testable, and aligned with real-world needs.

Confidentiality guidelines ensure that only public or pre-approved technical data is shared, promoting transparency while protecting commercial interests. This collaborative approach fosters innovation and accelerates the adoption of SF₆-free technologies.

The future of SF₆-free equipment

In an ideal world, SF₆-free switchgear would be the default choice wherever feasible. Standardization efforts will ensure that operators have confidence in adopting these technologies. The power grid is expanding to accommodate more renewable energy sources, and transitioning to SF₆-free equipment will prevent adding more SF₆ into the installed base.

As real-world experience with SF₆-free switchgear grows, the industry will refine standards further, ensuring continuous improvement and widespread adoption.

The transition to SF₆-free switchgear is a crucial step in reducing greenhouse gas emissions in the power sector. Standardization plays a vital role in ensuring safety, interoperability, and long-term sustainability. While challenges exist, international collaboration through organizations like CIGRE, IEC, and IEEE are paving the way for a standardized, eco-efficient future.

By establishing robust standards, we can create certainty for operators, encourage innovation, and ultimately enable a cleaner power infrastructure.

Connect with our experts to discuss how Hitachi Energy can support your high-voltage needs.