This article gives an overview on current international regulations, state-of-the-art SF6 gas handling equipment and SF6 re-use based on DILO’s “zero emission” philosophy.
Pros and cons
SF6 is a non-toxic, inert insulating and quenching gas of high dielectric strength and thermal stability and has been successfully used for more than four decades in enclosed medium and high voltage switchgear and circuit breakers.
SF6 gas offers numerous advantages in power transmission and distribution: SF6 insulated switchgear take up less surface area as they can be built in a compact way allowing substations even to be placed in narrowly spaced urban locations or underground. In addition to low maintenance needs and high operating reliability, gas insulated switchgear can be configured, compared to oil or air insulated electrical equipment, with higher voltages so that energy losses in T&D are kept to a minimum.
It is to be noted, however, that SF6 is also one of the six greenhouse gases listed in the Kyoto protocol. The non-toxic, non flammable and noncorrosive SF6 gas has a global warming potential of 22,800 times higher than that of carbon dioxide. In other words: When 1 kg of SF6 is released into the atmosphere it has the same greenhouse effect as a petrol-driven medium sized vehicle with a total mileage of around 120,000 km (emitting around 185 g of CO2 per km). The atmospheric lifetime of SF6 extends over 3,200 years.
Following these facts, special attention has to be paid to sustainable and emission-free SF6 gas handling.