There's a fundamental relationship between magnetism and electricity. If you've ever built an electromagnet, you've seen this in action. A simple electromagnet consists of a coil of copper wire wrapped around a core -- iron nails work well. Attach the ends of the copper wire to a battery. Electrons will flow through the copper wire and generate a magnetic field. You can use the copper-wrapped nail as a magnet.
While electricity can create a magnetic field, the reverse is also true. A magnetic field can create -- or induce -- electricity. If you introduce a magnetic field to an electrical conductor, you'll cause electrons to flow through the conductor as if it were connected to a power source. Use a strong enough magnetic field and the electricity flow will be significant.
The sun can produce incredible magnetic fields. During a solar storm, the magnetic force expelled by the sun is strong enough to change the shape of the Earth's magnetosphere. We call this a geomagnetic storm and it can wreak havoc on large electrical systems. Smaller systems, like your smartphone or computer, tend to be safe. Normally, solar storms only affect large conductors. But those large conductors can interfere with the operation of smaller systems.
A surge in electricity on a power grid is bad news. It can damage transformers and even snap power lines as more electricity surges through the system than it was designed to handle. In 1989, a geomagnetic storm caused malfunctions in Quebec's power grid. There was a complete blackout for about six million residents for nine hours. The total cost to the HydroQuebec system was $6 billion [source: Horne].
SPACECAST will help European nations predict when a geomagnetic storm will occur. In theory, it will give nations valuable time to adjust power grid loads to prepare for oncoming magnetic fluctuations. In the future, smart grid approaches may allow engineers the chance to distribute power loads in such a way that it doesn't disrupt customers.