Infrastructure protectionScientists urge making critical infrastructure more resilient to solar storms

Scientists predict the probability of a massive solar storm striking the Earth in the next decade to be 12 percent. The 23 July 2012 solar storm was pointed away from Earth and blasted safely into space, but had it been directed towards Earth, it would have produced the worst geomagnetic storm in more than four centuries, causing extensive electricity problems that could take years to resolve.

Should a solar storm be directed at Earth, policy makers and power grid operators would have just a few hours from the first signs until the full fury of the storm to secure critical assets. “The July 2012 solar storm was a shot across the bows for policymakers and space weather professionals,” U.S. solar researchers warned in the journal Space Weather.

According to the Insurance Journal, scientists and power grid operators are debating the amount of damage the grid would suffer during a massive solar storm. The U.S. National Academy of Sciences estimated in 2008 that the damage and disruption could reach up to $2 trillion with a full recovery time between four and ten years. “The loss of electricity would ripple across the social infrastructure with water distribution affected within several hours; perishable foods and medications lost in 12-24 hours; loss of heating/air conditioning, sewage disposal, phone service, fuel re-supply and so on,” according to a study funded by the federal government.

The North American Electric Reliability Corporation (NERC) characterizes severe geomagnetic storms as “high impact, low frequency” (HILF) risks, which tend to be difficult to manage because policymakers must decide how much funds to allocate on reducing a risk that would be devastating but has little chances of occurring. Emerging markets, where electricity and communications systems are supported by outdated equipment, will be the most vulnerable during a solar storm. According to NASA scientist Dr. Tony Phillips, “as society relies more and more on high technology such as GPS, the Internet, satellite communications and smart power grids, we also expose ourselves more and more to the dangers of stormy space weather.”

Measuring the severity of a solar storm depends on the size of the flare, the scale of coronal mass ejection, the speed at which it travels from the Sun to Earth, magnetic flux, time of day, and location of the direct hit. Solar researchers use the disturbance-storm time (Dst) index, recorded in nano-Teslas (nT) to measure how hard Earth’s magnetic field shakes after a solar storm. The more negative Dst becomes, the worse the storm. The worst solar storm on record occurred on 1 September 1859, observed in England by Richard Carrington, after whom the Carrington Event is named. The -850 nT event damaged the new telegraph systems installed in North America and Europe. The next solar storm reported in May 1921 also damaged telegraph services in the West, followed by a March 1989 -589 nT event that blacked out Quebec’s power grid in less than two minutes- the worst impact to date.

Scientists at Oak Ridge National Laboratory warned in 2010 that older electrical transformers should be replaced or upgraded to withstand the electrical currents from a solar storm. Grid operators already have plans on how to reboot power in the aftermath of a blackout, but they must now plan for repairing damaged assets in the aftermath of a solar storm. Replacing transformers promptly following a solar storm would be nearly impossible. High-voltage transformers are too large and expensive to build and store spare units. “It may take one week to move a 250,000-volt transformer a short distance in major metropolitan areas,” Oak Ridge explained. “Even the distance of a few miles may take an entire weekend, as a number of traffic lights have to be removed and reinstated as the load is moved at snail’s pace in special trailers and the route taken has to be fully surveyed for load-bearing capability by civil engineers.”