Present and future estimates of the European high voltage circuit breaker population and its SF₆ inventory and emissions

This paper presents estimates of the European High Voltage circuit breaker population and its SF₆ inventory. Data on power system topology obtained from the OpenStreetMap database are used in conjunction with TSO and industry input to obtain estimates for the present-day population and inventory, offering an alternative to estimates based on uncertain or incomplete reported inventories. Three strategies for replacing the existing population of circuit breakers are defined and compared based on their resulting need for new circuit breakers and total future emissions of SF₆. Two of these strategies are phase-out strategies aiming to eliminate SF₆ from the circuit breaker population completely, while the third is based on a continued use of SF₆ in circuit breakers. An accelerated transition to SF₆-free operation brings the largest reduction of emissions, but incurs economic and logistic penalties due to more circuit breakers to be commissioned. Future emissions are estimated to be 30 and 37 Megatonnes CO2e with the accelerated and gradual phase-out strategies, respectively. The accelerated phase-out requires approximately 30–50% more circuit breakers to be commissioned across all voltage levels by 2050.