What if the Power Went Out for Good?

Spring 2018 Insider

What if the Power Went Out for Good?

The Threat of Electromagnetic Pulse and What to Do About It

Apr 16, 2018 10 min read


Most everyone has experienced a temporary power outage. It’s always inconvenient, but when it stretches out for hours or even days, the loss of electricity can become highly problematic.

If you own a backup generator, you might get through it without much inconvenience. Otherwise, no television, internet, video games, hot showers, air-conditioning, microwave oven, or espresso maker. No charging your cell phone when it dies. With a gas stove, you can still cook. Maybe you catch up on your reading—by flashlight. 

If a blackout lasts more than a few days, you’ll need to make sure you stay supplied with fuel for your generator. Or buy more batteries for your flashlight. Maybe you think about getting a hotel room down the road.  

Of course, if a prolonged blackout is not limited to your neighborhood but is area-wide, then you will have to drive further to find comfort. Other people will do the same and the roads will be clogged. Back-up generators can do only so much—and for only as long as they remain fueled. Gas stations without backup power won’t have working pumps. Bank ATM machines could be down. Street lights and traffic lights may not be working, adding to the traffic woes. Maybe you think it’s time to take that trip to the Bahamas—if you can get to the airport and obtain a ticket. 

As inconvenient as a blackout might be, it’s just the starting point for understanding how difficult life could become if the United States were struck by a large electromagnetic pulse (EMP)—such as would be generated by the detonation of a nuclear bomb in the upper atmosphere. An EMP would threaten not just the power lines that distribute electricity to homes and businesses; it would threaten anything that is conductive—anything made of metal—with a current and voltage surge capable of overloading circuits. Your back-up generator won’t power a refrigerator—or any other appliance—whose circuits have been fried. After an EMP, your computer will be probably toast, too. 

One can imagine the possible cascading difficulties. Refrigeration systems could quickly fail and food reserves will spoil for lack of long-term backup power. Retailers, unable to process credit card transactions, will demand cash—at least as long as they have things to sell. Without computers to manage inventory, retailers will have difficulty keeping critical goods—like food and water—on the shelves. Pharmacies might not be able to restock prescription medicines. Compounding the inventory problem is the inability to manage traffic that will quickly cripple the roads. Your car will go only as far as the gas in your tank will take you (because, remember, gas pumps need electricity to operate). Garbage might go uncollected. Landlines will be gone. Your cell phone might work for as long as it can hold a charge. (Whether there are signals to receive is another question.) Hospitals and emergency responders will eventually be overwhelmed by these problems. And help may be hundreds of miles away, and a long, long time coming.

It sounds like dystopian science fiction, but an EMP has been a real possibility for as long as nuclear weapons have been deployable. What is perhaps different now is how increasingly dependent the American way of life is on access to electricity. Although experts debate the scale and long-term consequences of an EMP event, there is enough evidence to conclude that an electromagnetic pulse could cause tremendous damage to the electricity-based lifestyle on which we all depend. (For more information about the possible consequences of an EMP, see the National Geographic documentary, American Blackout, or visit

nyc blackout

BLACKOUT IN NEW YORK, NY. The Empire State Building in New York City remains dark during a power outage on August 14, 2003. credit: MICHAEL PEREZ/KRT/NEWSCOM)

From Where Do EMP Events Come?

An EMP event can affect the United States through an act of warfare or terrorism, or as a result of large solar storms. The most powerful and dangerous type of EMP event occurs when a nuclear weapon is detonated 30 miles or higher in the earth’s atmosphere. Such a nuclear explosion produces gamma rays, which sheer electrons off of air molecules. These electrons are then moved in a corkscrew pattern by the Earth’s magnetic field which produces a magnetic pulse lasting nanoseconds to seconds. This electromagnetic pulse radiates outward and downward from the burst point toward the earth’s poles, producing current and voltage surges that could damage electronics hundreds of miles from ground zero. 

The disruptive potential of a nuclear explosion was vividly demonstrated in the 1962 Starfish Prime test in which a U.S. nuclear bomb, detonated above Johnston Island in the South Pacific, disrupted electrical systems like lighting, circuit breakers, and alarms over 870 miles away in Hawaii. Closer to the blast site, the effects on unprotected electronic equipment were far more damaging.

Another potential cause of an EMP-like event is fluctuations in solar activity. Much like cyclical changes in the weather, scientists have observed variations in the sun’s thermal activity. One major flare in the 19th century, known as the Carrington Event for its namesake observer, astronomer Richard
Carrington, emitted an electromagnetic shockwave that, upon reaching Earth, caused telegraph machines to spark and fail. Some even shocked their operators. The world in 1859 did not depend very heavily on electricity so the effects were relatively confined. U.S. scientists from the National Academies have suggested that a solar flare today on the scale of the Carrington Event would result in tremendously greater electronic disruption at a cost of $1 trillion to $2 trillion. Solar storms like the Carrington Event are not one-off flukes. One will occur again in the future and when it does we should not be caught off guard. 

As inconvenient as a blackout might be, it’s just the starting point for understanding how difficult life could become if the United States were struck by a large electromagnetic pulse.

A radio-frequency weapon, sometimes referred to as an E-bomb or electromagnetic bomb, causes the least potent type of electromagnetic pulse. The scale of damage would be far more confined than a nuclear explosion, but such an attack would be harder to prevent because E-bombs are smaller and less technologically demanding than nuclear weapons, and therefore easier to conceal. In 1993, the U.S. military released the results of an E-bomb test that successfully shut down engine controls 300 meters away. This technology has been continually refined since that time and it is highly likely that U.S. adversaries possess similar capabilities.  

Consequences of EMP Events

The consequences of EMP events vary depending on the type of event. The damage depends primarily on the location and strength of the blast. In the worst case scenario, EMP has been likened to a lightning strike, only stronger and far more dispersed. All forms of electrical power within a certain radius, by some estimates up to half of the continental United States, could be affected. The electronic surge could disable phones and internet service, heating and cooling systems, water and sewage provision, refrigeration, transportation (cars, trains, planes), and automated transaction machines (ATMs). In short, all the means by which modern life has become more efficient, more convenient, and more secure could come crashing to a halt. The interconnectivity of power and electronics on which we depend could perversely serve to further spread the damage along power lines and satellite antennae. 

Looking at the experience of other power outages in modern American history helps shed light on what the results of an EMP might look like. In the aftermath of multiple lightning strikes on a Con Edison substation in 1977, New York City endured a day-long blackout that resulted in extensive property damage, looting, and over 3,000 arrests. Though costly and disruptive—estimates put the blackout’s price tag at $346 million—New York City’s single “Night of Terror” would pale in comparison to protracted outages caused by an EMP. 

The potential long-term consequences may be better represented by the 2003 blackout in the northeastern United States and Canada. Here the cascading effects of power failure were put on display as equipment failures originating in Ohio triggered further blackouts in New York, Maryland, Pennsylvania, Michigan, and Ontario. Residents were advised to boil water because water treatment systems were no longer functioning; without traffic lights, long lines of commuters backed up as they attempted to make their way home; cellular, cable, and internet services were all disrupted; and industrial production was shut down. Some auto plants in Detroit were closed for over a week. The disruption caused an estimated $6 billion to $10 billion worth of damage. Still, even this event was relatively contained and limited in comparison to the effects of nuclear-triggered EMP strike. Generators continued to work and in major urban areas power was restored more quickly.

The case of Puerto Rico after Hurricane Maria, where much of the population struggled without electricity for months, underscores the potentially deadly consequences of an EMP event. The lack of power compromised health and sanitation services for many. Bacterial infections—some resulting in death—rose sharply following the loss of power.Of course, the death toll would undoubtedly be worse were it not for the hundreds of millions of dollars in assistance and tens of thousands of volunteers and workers present to help distribute aid and rebuild infrastructure. 



We’ve been vulnerable to a manmade EMP for a long time—really ever since ICBMs could deliver a nuclear bomb to detonate 30 miles above the earth’s surface. But we are more vulnerable now that ever for three reasons. First, we rely on computers to do more things that ever before. Second, electronics using semi-conductors are more vulnerable to an EMP than are the older electronics based on vacuum tube technology. Third, the nature of the threat changed since the days of the Soviet rivalry during the Cold War. Today, terrorists and rogue states such as North Korea may see the threat of an EMP or E-bomb attack as the great equalizer between the powerful and the weak.

What to Do? 

EMP events are high impact, low probability events. Taking measures to improve awareness, enhance our defenses, better secure our infrastructure, and promote intra-governmental cooperation is essential to staying ahead of the threat. It’s the difference between facing an event that costs millions of dollars versus one that costs trillions and mitigating the nightmare scenarios described above. 

Successfully implementing any such plan requires recognizing that there is a role for citizens and electric utilities, as well as state and federal government agencies. An effective EMP preparedness strategy would implement the following policies:

1. Increase Public Awareness: For the wider public to care enough about EMP threats that they are willing to support preventative measures, they must first understand the threat. Local, state, and federal agencies—as well as the private sector—could do more to educate the public about the dangers. Armed with this information, communities and individuals would be better able to make necessary contingency plans to survive for a certain period of time without electricity. 

2. Advance U.S. Missile Defense Capabilities. Shooting down a nuclear warhead before it fulfills its objective is the best way to defend against the devastating consequences of an EMP. More investment in missile defense capabilities would best protect the United States from a nuclear EMP attack while also offering protection from nuclear weapon attacks. Improving missile defense protection of the East Coast of the United States would be especially worthwhile since the area is relatively more vulnerable than the West Coast, and since the East Coast electric grid is the most densely interconnected part of the grid. To this end, Congress’s decision in the most recent National Defense Authorization Act to authorize $13.8 billion for missile defense, $4.4 billion more than President Trump’s budget requested, suggests there is a growing bipartisan desire to improve our missile defense capabilities.

3. Identify and Protect National Security Infrastructure. Addressing the EMP threat is a complex task that will need to take place on many levels. At the top, Congress and the President need to start the process by identifying energy infrastructure that is key to national security and ensuring that it is hardened to resist the effects of EMP. For example, Air Force One has been designed to withstand the electromagnetic pulse of a nuclear bomb. Other critical defense installations receive similar protection. 

4. Increase Information Sharing Between Industry and Government. Absolutely critical to equipping the electric industry’s preparedness is controlled access to classified government information on the EMP threat as well as seeking partnerships between companies and federal research laboratories. These laboratories can contribute expertise in modeling and simulating the EMP threat since the United States no longer conducts nuclear weapon experiments. One encouraging sign on this front is the Department of Energy’s 2017 Electromagnetic Pulse Resilience Action Plan, which prioritizes greater testing and sharing of knowledge between industry and government agencies. In order to develop effective and efficient solutions, utilities need an accurate understanding of the challenge and what infrastructure—transformers, substations, sections of the grid, and computer systems among them—ought to be prioritized. The Maine legislature recently requested an analysis of their grid—a good first step on the way to greater security.

5. Develop Clear Lines of Communication for Crisis Scenarios. The Department of Homeland Security (DHS) needs to develop clear lines of communication with the electricity sector for crisis situations. If an EMP event took place tomorrow, there would be no standard operating procedures in place to guide public-private action in responding to the crisis. DHS should work in concert with industry as well as state governments to ensure that there is a clearly understood set of practices for delivering information and dealing with the major outages caused by EMP events. They should use opportunities like the Grid Security Exercise (GridEx) spearheaded by the North American Electric Reliability Corporation to test these communications. A better established chain of command and communication strategy will enable superior crisis management that restores the grid more quickly, saving lives and money in the process. 

Ms. Dodge is a senior policy analyst at The Heritage Foundation. Mr. Wilson was an intern at The Heritage Foundation in the fall of 2017.