One of the biggest disasters we face would begin about 18 hours after the sun spit out a 10-billion-ton ball of plasma–something it has done before and is sure to do again. When the ball, a charged cloud of particles called a coronal mass ejection (CME), struck the Earth, electrical currents would spike through the power grid. Transformers would be destroyed. Lights would go out. Food would spoil and–since the entire transportation system would also be shut down–go unrestocked.
Within weeks, backup generators at nuclear power plants would have run down, and the electric pumps that supply water to cooling ponds, where radioactive spent fuel rods are stored, would shut off. Multiple meltdowns would ensue. “Imagine 30 Chernobyls across the U.S.,” says electrical engineer John Kappenman, an expert on the grid’s vulnerability to space weather. A CME big enough to take out a chunk of the grid is what scientists and insurers call a high-consequence, low-frequency event. Many space-weather scientists say the Earth is due for one soon. Although CMEs can strike anytime, they are closely correlated to highs in the 11-year sunspot cycle. The current cycle will peak in July 2013.
The most powerful CME in recorded history occurred during a solar cycle with a peak similar to the one scientists are predicting in 2013. During the so-called Carrington Event in 1859, electrical discharges in the U.S. shocked telegraph operators and set their machines on fire. A CME in 1921 disrupted radio across the East Coast and telephone operations in most of Europe. In a 2008 National Academy of Sciences report, scientists estimated that a 1921-level storm could knock out 350 transformers on the American grid, leaving 130 million people without electricity. Replacing broken transformers would take a long time because most require up to two years to manufacture.
“We need to build protection against 100-year solar storms.”Once outside power is lost, nuclear plants have diesel generators that can pump water to spent-fuel cooling pools for up to 30 days. The extent of the meltdown threat is well-documented. A month before the Fukushima plant in Japan went offline in March, the Foundation for Resilient Societies, a committee of engineers, filed a petition with the U.S. Nuclear Regulatory Commission recommending the augmentation of nuclear plants’ emergency backup systems. The petition claims that a severe solar storm would be far worse than a 9.0-magnitude quake and could leave about two thirds of the country’s nuclear plants without power for one to two years.
Preventing a surge from a CME would be costly. With enough warning (at least a few hours, probably), power companies could shut transformers off entirely, turning them back on after the storm. But shutting down the grid on such a large scale would cost billions. To confidently do so, forecasting must be accurate.
Last October, NASA scientists announced its Solar Shield program to monitor solar eruptions and predict storms. Though a good step, the system uses a satellite that was launched in 1997 and designed to run just five years. No other country has anything similar, or as advanced.
Our backup systems aren’t in place yet, either. The Department of Homeland Security is funding the development of an emergency replacement transformer, but it won’t be field-ready for several years. Kappenman has developed a $100,000 capacitor to block storm-induced surges, but these are unproven in emergency situations. “A massive solar storm is a ‘low probability’ event the same way a 100-year flood is,” Thomas Popik, the author of the NRC petition, says. “Just as we build levees to protect against 100-year floods, we need to build protection against 100-year solar storms.”