Faraday’s law of induction means that if there is a time-varying magnetic field, then it can induce electrical currents in any conductive materials (e.g. wires, and even the ground). Coronal mass ejections from the Sun are sometimes able to significantly distort the Earth’s magnetic field. This change in the magnetic field results in electrical currents being induced in the ground and power lines running through the ground. These are the geomagnetically induced currents.
Electrical grid – Transformers
As we previously saw, the 1859’s solar storm had damaged the telegraph networks. However, nowadays, an important part of the world is connected to the electrical network, which makes the danger that much bigger. As a matter of fact, if the GIC are consequent, the electric transformers will be touched.
If the GIC are strong enough, they can damage the transformers. These transformers will heat up and be damaged. This overheating is caused by the electrical current of ICM (DC) that is not supported by the transformers(designed for alternating the current/electric). Such power failure can take even more breadth in case of transformers should be replaced. If such a storm arose, this one would affect 130 million people approximately, mainly in Europe and in North America so causing a generalized blackout.
The current flowing through the ground can have surprising consequences. For example, it can cause pipeline corrosion. Normally, pipelines are made of steel for the protection against the pressure. However, the steel is corrosive. In order to bridge this problem, a small current flows through pipelines (this current is opposite to that of ground). During a solar storm, GIC impact this current which nullifies any protection. The pipelines are, therefore, weakened and need to be changed on a regular basis (high cost).