Solar storms affect Earth's ionosphere, causing disruption of short-wave radio communications, navigation systems on ships and aircraft, and military radar systems.
Surges in long electrical lines may cause widespread power blackouts. The most famous of those happened in Quebec in 1989, when 6 million people were left without electricity.
Damage to microchips, and electrical discharges, may cause satellites to stop operating, causing disruption of telephone, TV and data communications services.
Radiation levels can become hazardous to astronauts and occupants of high-flying aircraft.
High-energy particles hitting the Earth's upper atmosphere can erode the ozone layer, which protects us from the harmful ultraviolet radiation.
Solar storms have also been blamed for increased corrosion in oil pipelines.
