A Brief History of Solar Superstorms

While damage to electronics from electromagnetic pulse (EMP) caused by atomic bombs detonated high above the stratosphere would seem to be a remote possibility, very real damage has occurred from solar superstorms…

Shortly after midnight on September 2, 1859, campers in the Rocky Mountains were awakened by an “auroral light, so bright that one could easily read common print. Some of the party insisted that it was daylight and began the preparation of breakfast”, according to the Rocky Mountain News. Magnetic observatories world-wide recorded disturbances in Earth’s field so extreme that magnetometer traces were driven off scale, and telegraph networks experienced major disruptions and outages. The electricity which attended this beautiful phenomenon took possession of the magnetic wires throughout the country, the Philadelphia Evening Bulletin reported, and there were numerous side displays in the telegraph offices where fantastical and unreadable messages came through the instruments, and where the atmospheric fireworks assumed shape and substance in brilliant sparks. In several locations, operators disconnected their systems from the batteries and sent messages using only the current induced by the aurora. In Havana, Cuba, the sky that night appeared “stained with blood and in a state of general conflagration” and auroras were observed as far south as Hawaii and northern Venezuela (Figure 1). A British amateur astronomer, Richard Carrington, observed an outburst of “two patches of intensely bright and white light” from a large and complex group of sunspots the the center of the Sun’s disk the previous day, and so the solar storm of 1859 has been dubbed “the Carrington event”. It remains the most severe solar storm to affect the Earth in recorded history.

…this was in 1859, long before the advent of electricity being common in homes and businesses.  While delicate electronics would seem to be the most vulnerable, the real potential problems are massive transformers used by utilities…

The strong electric currents that would flow through the the electrical grid during a repeat of the Carrington event are likely to cause melting and burn-through of large-amperage copper windings and leads in electrical transformers. These multi-ton, multi-million dollar devices generally cannot be repaired in the field, and if damaged in this manner, they need to be replaced with new units. There are only a handful of spares in reserve, so most of the region affected by the collapse would remain without power until new transformers could be custom built. During the March 13, 1989 Superstorm, geomagnetic-induced currents (GICs) melted the internal windings of a 500kV transformer in the Salem Nuclear plant in southern New Jersey (Figure 3). The entire nuclear plant was unable to operate until this damaged transformer was replaced. Fortunately, a spare from a canceled nuclear plant in Washington State was available, and the Salem plant was able to reopen 40 days later. Had the spare not been available, a new custom-built transformer would have been required, potentially idling the power plant for years.

…and not only are these devices manufactured in but one factory in the U.S., the lead times for replacements are nearly three years.  This is one of those “black swans” you hope never lands and a good reason to become more self sufficient with solar panels and a backup generator.