Solar flares are enormous outbursts of power. Within a few short minutes, the disturbance on the surface of the Sun spreads along the Sun’s magnetic field lines, releasing energy equivalent to billions of nuclear explosions (producing X rays) and raising the temperature of the flare region (which is about the size of the Earth) to tens of millions of degrees and lasting minutes to hours.
The upcoming solar storm, largest in five years, will result in charged particles hitting Earth at 6.4 million km/h. The streams of charged particles could have more than 10 million MW of electrical power. When these charged particles hit the earth’s atmosphere, they excite the atoms in the atmosphere. These trillions of excited atoms, when they de-excite, will give off the excess energy in the form of light, called auroras.