If we were hit with another Carrington-sized storm, the report said, it could take months to get parts of the grid back to functional. In the first year alone, it would take an economic toll of $2 trillion, about 20 times the cost of Hurricane Katrina.
According to Petrovay, the worst effects of the flare would be felt in North America, where the highly-connected grid could exacerbate problems and systems running near peak capacity have less room for error. "I have doubts whether [a solar storm] would really take out the whole grid, but probably shutdowns would occur in many places," he said.
So how can the U.S. avoid going dark?
Advocates say the solution is as simple as surge protectors Americans use to protect their personal computers — though on a much larger scale.
The coalition wants such protectors placed across the electrical grid to block harmful currents. In addition, advocates want to protect the extra-high-voltage transformers we depend on with metal, current-absorbing boxes called Faraday cages.
And more replacement parts, especially the giant transformers that can take years to make, need to be at the ready in case we lose critical pieces of the grid. That way, even if an EMP damaged key infrastructure elements, the U.S. would have replacements ready to go.
Without those backups, blackouts could last up to two years, said the Lloyd's report. Pry pegs it somewhere between four and 10 years. "That's optimistic because it assumes people would live that long," he said.
These aren't new solutions. In 2010, the House passed the GRID Act, which would have protected 300 of the country's biggest transformers. The measure died in the Senate later that year.
Last June, Reps. Trent Franks and Yvette Clarke introduced the SHIELD Act, which mandates many of the same safeguards.
When the bill was introduced, Gingrich voiced his support, but the House Energy and Commerce Committee has yet to take it up. For that, Pry blames Chairman Fred Upton, who he says is beholden to electricity utilities that don't want Congress to assert regulatory authority over the power grid.
Upton's staff responded with a statement following a Wednesday grid security briefing. "We have been active in our oversight of the nation's energy grid vulnerabilities and we remain vigilant over all emerging threats to the grid, including cyber and physical attacks, solar storms, and electromagnetic pulses," Upton said.
According to the coalition, protecting the electrical grid would cost only $2 billion, and could be completed in less than five years. Safeguarding all essential infrastructure would come in between $10-20 billion.
Those who are OK with the status quo, Pry says, are "like the zeppelin industry in the 1920s." By his estimate, utilities could fund grid-protecting efforts by tacking on just 20 cents per year to ratepayers' bills.