InfrastructureProtecting the grid from solar storm-induced blackouts
Since the beginning of the Space Age the total length of high-voltage power lines crisscrossing North America has increased nearly ten fold; this has turned power grids into giant antennas for solar storm-induced currents; with demand for power growing even faster than the grids themselves, modern networks are sprawling, interconnected, and stressed to the limit — a recipe for trouble
Every hundred years or so, a solar storm comes along so potent that it fills the skies of Earth with blood-red auroras, makes compass needles point in the wrong direction, and sends electric currents coursing through the planet’s topsoil. The most famous such storm, the Carrington Event of 1859, actually shocked telegraph operators and set some of their offices on fire. A 2008 report by the National Academy of Sciences warns that if such a storm occurred today, we could experience widespread power blackouts with permanent damage to many key transformers.
What should utility operators to do?
A new NASA project called Solar Shield could help keep the lights on.
“Solar Shield is a new and experimental forecasting system for the North American power grid,” explains project leader Antti Pulkkinen, a Catholic University of America research associate working at NASA’s Goddard Space Flight Center. “We believe we can zero in on specific transformers and predict which of them are going to be hit hardest by a space weather event.”
News@NASA reports that The troublemaker for power grids is the “GIC” — short for geomagnetically induced current. When a coronal mass ejection (a billion-ton solar storm cloud) hits Earth’s magnetic field, the impact causes the field to shake and quiver. These magnetic vibrations induce currents almost everywhere, from Earth’s upper atmosphere to the ground beneath our feet. Powerful GICs can overload circuits, trip breakers, and in extreme cases melt the windings of heavy-duty transformers.
This actually happened in Quebec on 13 March 1989, when a geomagnetic storm much less severe than the Carrington Event knocked out power across the entire province for more than nine hours. The storm damaged transformers in Quebec, New Jersey, and Great Britain, and caused more than 200 power anomalies across the United States from the eastern seaboard to the Pacific Northwest. A similar series of “Halloween storms” in October 2003 triggered a regional blackout in southern Sweden and may have damaged transformers in South Africa.
While many utilities have taken steps to fortify their grids, the overall situation has only gotten worse. A 2009 report by the North American Electric Reliability Corporation (NERC) and the U.S. Department of Energy concluded that modern power systems have a “significantly enhance[d] vulnerability and exposure to effects of a severe geomagnetic storm.” The underlying reason may be seen at a glance in this plot:
Since the beginning of the Space Age the total length of high-voltage
