The last recorded Solar Superstorm called the "Carrington Event" occurred over a period of nine days in 1859. It is is believed to have been caused by an explosion on the sun equivalent in force to a billion hydrogen bombs. Auroras were seen as far south as the Caribbean, and telegraph networks failed across the Northern Hemisphere, in some cases even catching fire.
Nobody knows when another storm of this size will envelop our planet, but a recent estimate published in the International Journal of Research and Applications says that there is a one in eight chance of this happening within the next decade. If it does, electrical grids throughout the world will not just fail, but be destroyed. NASA warns that such an event would cause "an avalanche of blackouts carried across continents [that] " could last for weeks to months."....
The good news is that the problem can be solved -- in the US at least -- by a one billion dollar investment in new equipment. That is one twentieth of what the military spends every year for air-conditioning in Iraq and Afghanistan. For that amount we could harden the vulnerable transformers, install ground resistors and create replacement parts for our imperiled electric grid....