Geomagnetically induced currents (GICs) due to space weather can impact electric power networks via transformer saturation, reactive power consumption, and increased total harmonic distortion. In the worst case, these can lead to widespread outages and damage to transformers. Investigating large geomagnetic storm events allows the power industry to better understand and mitigate the associated risks. Here we focus on the impacts in Alberta, Canada during the October 10–12, 2024 geomagnetic storm by modelling GICs in the ≥240 kV power network validated with transformer neutral-to-ground (TNG) GIC measurements. Despite the October 2024 storm being smaller than the May 2024 storm according to global storm disturbance indices, measured GIC exceeded 25 A/phase at three transformers in central Alberta and modelling suggests that the TNG GIC at some transformers in northeastern Alberta exceeded 30 A/phase, similar to the magnitude of the GICs seen during the May 2024 storm. For the October 2024 event, the cause of the largest geoelectric fields and largest GICs is spatially and temporally variable. Large events in northeastern Alberta were linked to the sudden storm commencement, with some large dusk-side events in southern Alberta being linked to a low-latitude substorm. The most spatially-extensive large geoelectric field event was associated with a large nightside substorm which developed over Alberta. In addition to GICs flowing at high voltage levels, the October 2024 storm also resulted in adverse technological impacts in northeastern Alberta at lower voltage levels. These included 34.5 kV capacitor banks and large 13.8 kV mine shovels tripping offline at industrial mining operations. The capacitor bank trips were likely due to increased total harmonic distortion due to transformer saturation from GIC at higher voltage levels, while the mine shovel trips may have been due to a unique failure mode related to induced current on long (∼10 km) low-current 30 V DC ground check circuits. To our knowledge, this is the first time that direct space weather impacts on mining operations have been reported in the literature.
Cordell et al. (Thu,) studied this question.