One of the most famous examples is the Carrington Event of 1859, considered the strongest geomagnetic storm ever recorded. Telegraph systems around the world experienced failures, sparks, and unusual electrical activity.
At the time, global society was far less dependent on electronics than it is today. As a result, experts frequently examine how a similar event might affect modern infrastructure.
More recent solar storms have caused temporary satellite issues, radio blackouts, and power grid disturbances. These events provide valuable data that helps researchers improve forecasting and preparedness efforts.