EU F-Gas Regulation: Beyond the SF₆ switchgear phase-out

Siemens Energy began exploring alternatives to SF₆ in 2010, when the company tested prototype high-voltage vacuum circuit breakers. Series production followed, with the first units installed from 2017. In the same year, Siemens Energy commissioned its first F-gas-free 72.5 kV gas-insulated switchgear (GIS), using clean air and vacuum switching, in an offshore wind application. In 2018, Siemens Energy received an order from the Norwegian utility BKK Nett for a 145 kV gas-insulated switchgear for a substation in Bergen, the world’s first 145 kV F-gas-free GIS using clean air and vacuum interruption, which was later energized in 2020. “Our interest in SF₆-free switchgear technology comes from a genuine commitment to sustainability and the practical need to avoid problems in the future,” said Jens Skår, Division Manager at BKK Nett. “Someone had to take the first step.” 

At its Berlin factory, Siemens Energy produces vacuum interrupters. In Pearl, Mississippi, a new high-voltage switchgear facility is under construction, with an investment of up to $300 million. As of mid-2026, Siemens Energy has delivered 2,870 units of gas-insulated switchgear for installation in offshore wind park towers. And the company continues to innovate by developing F-gas-free switchgear at 245 kV and 420 kV, in collaboration with European grid operators and EU co-funding.

Overall, SF₆-free switchgear is part of a broader transition, especially in Europe. According to a market survey by Öko-Recherche and RE-xpertise on the implementation of the new F-gas rules, commissioned by the European Commission and presented in October 2025, volumes of F-gas-free switchgear placed on the market have roughly doubled since 2020, with growth expected to continue over the next five years. And while SF₆ remains predominant in the grid, it is no longer the default in new installations at 145 kV and below. For example, at medium voltage up to 24 kV, all seven manufacturers that responded to the survey offer F-gas-free products. At high voltages of 52 kV up to 145 kV, they also offer F-gas-free air-insulated switchgear, and several offer or are introducing F-gas-free gas-insulated switchgear.

In February 2024, the main legislation introducing stricter restrictions on F-gases in electrical equipment, the EU F-Gas Regulation 2024/573, was published. The regulation aligns with the EU Green Deal, reaffirming the EU’s goal of becoming the first climate-neutral continent by 2050. It also fits within a wider international framework. The 2016 Kigali Amendment to the Montreal Protocol commits countries worldwide to phase down high global warming potential (GWP) hydrofluorocarbons. In fact, the EU’s F-gas Regulation ensures compliance with the amendment. 

While the EU’s phase-out pathway for F-gases in electrical equipment is ambitious (and, at first glance, a bit complicated), it is achievable, giving manufacturers and grid operators a clear direction. The regulation does not ban existing switchgear with SF₆. Instead, it prohibits new electrical switchgear that uses fluorinated greenhouse gases after specified deadlines (see table). 

The advantages of SF₆ are no longer enough. EU-wide SF₆ supply jumped more than 60% in 2024. While that figure partly reflects a broadened reporting obligation under the new regulation, it also indicates stockpiling ahead of the looming bans. But the first signs of a reversal are visible: in Germany, official figures show SF₆ sales to the electricity sector fell 21.5% in 2025, indicating that the new rules are having an effect.

So which option should grid operators choose? The main alternatives to SF₆ are clean air or natural-origin gases, such as nitrogen, oxygen, and carbon dioxide, on the one hand, and fluorinated gas mixtures with a fraction of SF₆'s climate impact on the other. But some of these fluorinated alternatives still have a GWP of roughly 300-700. They may also face more regulatory restrictions in the EU and other regions, because they belong to the per- and polyfluoroalkyl substances (PFAS), the “forever chemicals” currently under EU-wide restriction assessment. Clean air and vacuum-based solutions, in contrast, are better positioned for future regulation: they avoid both the high-GWP issue and the PFAS-related risk. Unlike SF₆ and other F-gases, they require no careful handling, recycling, or reporting. 

At the highest transmission voltages, F-gas-free switchgear is too demanding and capital-intensive for any single manufacturer to validate on its own. So, public funding and customer co-creation are helping move these technologies into the field. Siemens Energy is participating in several EU co-funded innovation programs that accelerate the development of SF₆-free technologies. Here are three of these projects.

Under Horizon Europe, the MISSION project, coordinated by SINTEF Energy Research, includes the world's first 420 kV AC live-tank vacuum circuit breaker, combining vacuum interruption with clean air insulation at a GWP of zero. It’s built to the same dimensions as today's SF₆ units, so it can be retrofitted without rebuilding the bay. Having proven the technology in a prototype, Siemens Energy will see it installed by the French and Norwegian operators RTE and Statnett in late 2026.

It's clear that SF₆-free switchgear is no longer just a promise. Clean air insulated electrical equipment, as well as solutions insulated with fluorinated gas and a low GWP, are already in operation. In addition, the EU F-Gas Regulation 2024/573 has set deadlines across all voltage ranges. And projects like MISSION and LIFE Blue are closing the gap at the highest voltages, where replacing SF₆ is the hardest. However, one challenge still remains: the installed base turns over slowly. Newly installed SF₆-insulated electrical equipment will remain in operation for decades. That’s why operators’ procurement decisions made today will determine how quickly Europe can realize the F-gas-free grid of tomorrow.