Switchgear

Illustration of a typical gas-insulated switchgear Click to enlarge
Illustration of a typical gas-insulated switchgear
Source: Ecofys

Sulphur hexafluoride (SF₆), which has a very high global warming potential, is used for insulation and arc quenching in switchgear. SF₆ emissions have been successfully reduced thanks to a voluntary industry commitment. Alternative products to substitute SF₆ in various applications have been developed.

News

EU Regulation on fluorinated greenhouse gases

SF6 has been used for many years in electrical equipment for power transmission and distribution in the medium-voltage and high-voltage range. Due to its high global warming potential of 24 300 (IPCC 6. Assessment Report) or 22 800 (Regulation (EU) 517/2014) and the long atmospheric lifetime, this substance accumulates in the atmosphere.

Electrical switchgear is subject to the provisions of EU Regulation 517/2014. Depending on filling volume and construction type, different requirements apply for leakage control, record-keeping, and certification of personnel. Implementing Regulation (EU) 2015/2066 goes into greater detail concerning certification of personnel.

Regulation (EU) No 517/2014 on fluorinated greenhouse gases is being revised. A ban on SF6 for new installations is being discussed (see News above). Especially in medium voltage switchgear, halogen-free alternatives are available from many companies. Therefore a ban on the commissioning of new installations for SF6 switchgear up to 24 kV could already apply there from 01.01.2026. Other voltage levels could follow step by step. For public buildings in Germany, the General Administrative Regulation on the Procurement of Climate-friendly Services (AVV Klima) already prescribes the preferential procurement of SF6-free medium-voltage switchgear in tenders for public contracts.

The amount of SF6 installed in switchgear is steadily increasing. Careful handling of the equipment at the end of its life is essential to avoid the emission of this quantity or partial quantities of it. Certification for work on switchgear containing SF6 is required not only for maintenance, servicing and repair, but also for decommissioning. The operator of electrical equipment is responsible for compliance with this regulation.

Project on the recovery of SF6 from electrical equipment

In the research project "Practical recovery factors for UNFCCC F-gas inventories" (duration from 2022 to 2024), country-specific emission factors for disposal are to be reviewed for high and medium voltage switchgear, among other things. In addition, the current national disposal practice for switchgear is to be examined more closely. A workshop on the topic was held with selected stakeholders in May 2023. Further research will follow. The results will be published at the end of 2024 with the final report of the project.

Project on electrical equipment

A study on the transmission and distribution of electrical energy without the use of SF6 (Konzept zur SF6-freien Übertragung und Verteilung elektrischer Energie) was being conducted on behalf of the Federal Ministry for Environment, Nature Conservation, Building and Nuclear Safety (BMU) from 2016 to 2018. One major focus of the study was the drafting of a detailed overview of systems which do and do not use SF6. Also suitable policy, legislative, regulatory and economic measures to achieve an effective reduction of SF6 in new systems were explored. SF6 technology can only be substituted by alternative insulating media and techniques in the production of new equipments, the study focused exclusively on new devices. The intensive dialogue with manufacturers and operators throughout the project duration was very important in this context.

The project was carried out by Ecofys Germany GmbH in cooperation with ETH Zürich until February 2018. The German Environment Agency provided professional advice. After an intensive dialog with manufacturers and users through interviews and expert workshops the project was concluded with the publication of the final report (revised version) as well as a short summary.

German industry's voluntary commitment

The Federal Republic of Germany together with the German industry reached an agreement on global warming prevention on 9 November 2000. In this context, SF6 producers as well as manufacturers and operators of electrical equipment > 1kV made a voluntary agreement to reduce SF6 emissions. This agreement was first set up and signed in 2005.

During this voluntary commitment, emissions of SF6 from production and use in Germany have decreased significantly.

The chart shows that the emissions of electrical equipment in Germany has declined up to the year 1998: from approx. 50 tons in 1998 to approx. 10 tons in 2021.
Emissions of electrical equipment in Germany
Source: Umweltbundesamt