Space invasion: Solar storms pose critical threat to US infrastructure
On September 1, 1859, the most powerful geomagnetic storm of modern times hit the Earth. Aurorae, normally visible only at high latitudes, reached the Caribbean. The glow over the Rocky Mountains was so bright, gold miners reportedly exited their tents and began preparing breakfast. Telegraphs failed across the world — though in some areas, they continued to send and receive messages, even after being disconnected from their electrical supplies.
The event became known as the Carrington Event, after British astronomer Richard Carrington — but what caused small problems and unusual events in the 1800s would be absolutely devastating today. The handful of moderate geomagnetic storms in the last 40 years have caused significant damage to the grid; a full hammerblow would destroy the US electrical grid for several years. The economic impact of a similar disaster today is estimated at $2.6 trillion.
Often, when online publications write disaster-themed science stories, there are a number of comforting facts buried below the lede to take the edge off. Sure, a dinosaur-level extinction event could make for a really rocky millennium or two on Earth, but the chances of a rock that big hitting the planet are minuscule. Reading up on the potential impact [PDF] a coronal mass ejection (CME) could have on Earth offers no such comfort. (Read: Tesla turns in his grave: Is it finally time to switch from AC to DC?)
The truth is, solar flares as large as the one that caused the 1859 Carrington Event happen fairly regularly. Since we started monitoring the Sun’s solar cycle, we’ve gotten lucky on a number of occasions — CMEs that would have hit us even harder than 1859 have merely glanced us due to a non-ideal trajectory. Meanwhile, the United States’ grid is more vulnerable to such events than ever before — our transformer grid is, on average, nearly 40 years old, high-voltage power lines are carrying far more energy than they used to on a day-to-day basis, and there’s virtually no way to quickly repair the damage such a storm would cause.
Cloudy with a chance of civilization-crippling electromagnetic forces
Just how much of a threat is this? We consulted the Department of Energy’s own research to get a better idea. According to that report, transformers are custom-designed, highly intricate, take up to two years to manufacture, cost between $5-7 million apiece, and weigh between 100 and 400 tons. Ordinary transformers are far too bulky and heavy to ship by road, and must be moved around the country in specially-designed railcars. Smaller models are available, but are typically more expensive.
The United States power grid is utterly incapable of weathering a devastating geomagnetic storm. In worst-case scenarios, the sheer amount of energy flowing down the high-voltage wire would blow transformers in quick succession. The automatic load balancing and considerable safety margins that are built into plants are designed to deal with terrestrial disasters, not space invasions. Offline power capacity normally used for supplementing baseline power during peak hours might survive, but these plants are not staffed or fueled for long duration. Up to 92% of the Northeast’s power generation capability could be taken offline for periods of several years.
A cascade failure that took out such a huge swath of our power generation would have untold downstream effects as people lost the ability to contact emergency services, lost water pressure in areas that rely on electrical pumps, and were forced to rely on limited generator power. The damage estimates aren’t just theoretical — we know the electrical grid is sensitive to such geomagnetic storms after a surge in 1989 caused a major failure of a hydroelectric generator in Quebec. In the wake of that event, some of the US-based power companies instituted safeguards, but they’re woefully lacking compared to what could hit us.
Infrastructure protection
Even moderate geomagnetic storms cause significant damage or accelerate failures in equipment. Two years after the 1989 storm, 12 mid-sized transformers had failed — all of them significantly earlier than had otherwise been expected. During solar storms on April 3-5 1994, major transformers failed in Illinois at the Zion Nuclear plant as well as facilities in Braidwood and at the Powerton coal plant.
The windings in this transformer were oil-cooled and rated for 3000 amps.
Unlike dinosaur-level extinction events, geomagnetic storms that cause enormous disruptions in the Earth’s magnetic field are a regular phenomenon and were reported widely in historical journals and writings, stretching back to the dawn of human history. Storms with the power of the 1859 CME hit, on average, every 154 years.
