Possibilities for minimising sulphur hexafluoride use for HV switchgear asset renewal: An Australian case study

The 40 year dominance associated with SF6 insulated HV switchgear is placing utilities in potentially vulnerable environmental positions. With the ongoing replacement of obsolete oil designs expected to finalise in the next decade, then Australian circuit breakers 66 kV and above could be near 100% SF6 insulated by 2025. Despite a recent fall in national electricity demand, infrastructure upgrades and the diversifying renewable generation mix are supporting continual SF6 insulated equipment growth. As a result, probable global environment driven regulated SF6 price rises based on global warming potential of carbon based compounds or even application bans are of increasing concerns to network utilities. This Australian case study provides a sample survey outcome of SF6 use in a regional transmission and distribution network, with reasonable and practical recommendations for use of pro-active technology implementations and trials that will help alleviate reliance on SF6. The proposed outcomes operate within normal asset renewal network operating budgets whilst simultaneously offering environmental and occupational safety beneficial alternatives.