Disadvantages of SF6 Circuit Breakers Highlighted by Experts

Experts in the power industry are raising concerns about the use of sulfur hexafluoride (SF6) gas in high-voltage circuit breakers, citing its environmental and safety drawbacks. SF6, a potent greenhouse gas with a global warming potential of over 23,000 times that of carbon dioxide, is used as an insulating and arc-quenching medium in switchgear and circuit breakers that operate at high voltage levels.

According to a report by the International Energy Agency, SF6 emissions from the electricity sector amounted to 10.3 million metric tons in 2018, equivalent to the annual emissions of 2.3 million cars. The use of SF6 in switchgear and circuit breakers accounts for about 80% of the total SF6 emissions from the power sector, the report said.

While SF6 has desirable properties such as high dielectric strength, thermal stability, and non-flammability, its disadvantages are also significant. SF6 is a potent greenhouse gas that can remain in the atmosphere for thousands of years, contributing to climate change and ozone depletion. SF6 is also a toxic gas that can cause severe health effects if inhaled, such as asphyxiation, pulmonary edema, and blindness.

In addition, the use of SF6 circuit breakers requires special handling and maintenance procedures due to the risk of gas leaks and explosions. SF6 gas is stored in high-pressure cylinders and must be handled with care to avoid leaks or releases. In case of a fault or failure, SF6 circuit breakers can emit hazardous byproducts such as sulfur dioxide, sulfuric acid, and fluorine compounds.

Several countries and regions have already taken steps to phase out or reduce the use of SF6 in switchgear and circuit breakers. The European Union has set a target to reduce SF6 emissions by 55% by 2030 and ban the use of SF6 in new equipment from 2025. California, one of the largest electricity markets in the world, has also adopted regulations to limit the use of SF6 in transmission and distribution equipment.

Experts urge more countries and utilities to follow suit and explore alternative technologies that can replace SF6 circuit breakers without compromising reliability and safety. Possible options include vacuum interrupters, gas-insulated switchgear with alternative gases, and hybrid switchgear that combines different technologies.

"The drawbacks of SF6 are well-known and cannot be ignored any longer," said a spokesperson for a leading energy company. "We need to act responsibly and proactively to reduce our environmental footprint and protect public health. There are viable alternatives to SF6 that are available and affordable, and we should accelerate their adoption."