What Is a Solar Flare and Can It Really Knock Out the Power?
Over the past few days, several European countries—including Spain, Portugal, France, and Belgium—have experienced widespread power outages. Utility companies scrambled to restore electricity, while officials investigated potential causes.
Among the theories being discussed? Solar flares.
Let’s break down what solar flares are—and whether they really have the power to shut down the grid.
What Is a Solar Flare?
Solar flares are massive bursts of energy that erupt from the surface of the Sun. During these events, the Sun releases high-energy radiation and charged particles into space. When these reach Earth, they interact with our planet’s magnetic field. Solar flares are most common during the peak of the Sun’s 11-year activity cycle.
In some cases, the interaction between a strong solar flare and Earth’s magnetic field can trigger what’s known as a geomagnetic storm.
How Do Solar Flares Affect Power Systems?
Geomagnetic storms cause rapid, powerful changes in Earth’s magnetic field. These changes can affect long-distance power transmission lines by inducing electric currents within them. Since the U.S. power grid includes thousands of miles of high-voltage lines, it’s especially vulnerable to these effects.
When excess current flows through the grid, it can overload transformers and other components—leading to voltage instability, equipment failure, and even large-scale blackouts.
The currents often travel through the grounding systems of transformers and generators, which can result in serious damage.
Have Solar Flares Caused Blackouts Before?
Yes—and the most well-known example happened in 1989. After a major solar flare, a geomagnetic storm struck Earth, taking down the power grid in Quebec, Canada. About 6 million people were left without electricity for over nine hours.
Go even further back to 1859, and you’ll find the Carrington Event—the largest recorded solar storm. Telegraph systems around the world failed, and some lines even caught fire due to the extreme electrical surges.
Should We Be Concerned in the U.S.?
Absolutely. While such events are rare, they’re not science fiction. U.S. power grids, especially in the Northeast and Midwest, could be at risk during a severe solar storm. That’s why NASA and NOAA closely monitor solar activity and issue alerts when solar storms are expected.
If you’re into space weather, infrastructure, or just want to know what could suddenly knock your Wi-Fi offline—solar flares are worth keeping an eye on.
