Estimating the Norwegian circuit breaker population towards 2050

SF6-based circuit breakers (CBs) are to be replaced by SF6-free technology to reduce emissions of SF6 and comply with EU regulations. This paper aims to assess the impact of this transition in Norway in terms of the number of components required and reduction of emissions. The Norwegian CB population and its future development towards 2050 is estimated, along with the number of CBs needed to meet network expansion and replacement of older components. From this, the SF6 inventory and leaks are calculated. Two strategies for decommissioning existing CBs are compared: enforcing SF6-free operation by 2050 (“SF6-free by 2050”) or allowing CBs to reach their natural end-of-life (“Business as usual”). Assuming SF6-free technology becoming available according to timeline in EU’s regulations, “SF6-free by 2050” reduces the total emissions by 15% compared to “Business as usual”. The reduced emissions come at the expense of more CBs as “SF6-free by 2050” requires 10-50% more CBs to be commissioned by 2050, with the biggest increase seen at higher voltages where SF6-based technology is currently the norm. A delayed availability of SF6-free technology further increases the total emissions from the system and the need for new CBs to reach SF6-free operation in 2050.