How Are Electric Power Transmission Grids Affected?

Throughout giant magnetic storms, the extraordinary currents flowing in the ionosphere induce currents in the Earth's surface referred to as GICs (ground induced currents). Some rocks carry current higher than others. Igneous rocks don't conduct electricity terribly well thus the currents tend to require the path of least resistance and flow through man-made conductors that are present on the surface (love pipelines or cables). Regions of North America have important amounts of igneous rock and so are particularly vulnerable to the effects of GICs on man-created systems. Currents flowing in the ocean contribute to GICs by coming into along coastlines. GICs will enter the advanced grid of transmission lines that give power throughout the U.S. and alternative parts of the world through their grounding points. The GICs are steer current (DC) flows. Beneath extreme area weather conditions, these GICs will cause serious issues for the operation of the ability distribution networks by disrupting the operation of transformers that step voltages up and down throughout the network.