Protecting Your Electronics from an EMP Attack or Severe Solar Storm

Protecting Electronics from an EMP Attack or Severe Solar Storm

What would happen if, in an instant, electricity went away.

If all the things we depend upon for our everyday activities suddenly stopped working?

If our supplies of gas, water and sanitation were suddenly and completely cut off, how would we manage to survive?

A nuclear EMP in the atmosphere above North America could make it all go away because it would destroy the infrastructure upon which our technology depends.

Ambassador Hank Cooper who served at the Air Force Weapons Laboratory in the 1960s and later oversaw the Department of Defense programs to harden the Air Force Strategic Systems including the Command, Control and Communications Systems to assure they could operate after a Soviet nuclear EMP attack. He was also President Reagan’s Chief Negotiator at the Defense & Space talks with the Soviets and the Director of the Strategic Defense Initiative (SDI) during the George H.W. Bush era where he worked to assure our ballistic missle defense systems were hardened against EMP effects stated:

“The EMP problem is surely an existential threat to our society.  It can be done by folks who wish us ill and are willing to commit suicide to pull it off. It would make 9/11 look like a piker and 100s of millions of Americans could die.”

The threat of a sudden EMP attack that causes a widespread catastrophe is certainly nothing new. Consider this quotation from a widely-read and highly-respected publication more than 30 years ago:

“The United States is frequently crossed by picture-taking Cosmos series satellites that orbit at a height of 200 to 450 kilometers above the earth. Just one of these satellites, carrying a few pounds of enriched plutonium instead of a camera, might touch off instant coast-to-coast pandemonium: the U.S. power grid going out, all electrical appliances without a separate power supply (televisions, radios, computers, traffic lights) shutting down, commercial telephone lines going dead, special military channels barely working or quickly going

— from “Nuclear Pulse (III): Playing a Wild Card” by William J. Broad in Science magazine, pages 1248-1251,June 12, 1981.  silent.”

High altitude EMP detonation depiction
High altitude EMP detonation depiction

The situation would be much worse today than in 1981 due to our growing dependence upon electricity and electronics for the basic necessities of our lives.

Since then there has been an enormous increase in our dependency on electronics, computers, and microelectronics. The more vulnerable the U.S. Is to such an attack the more likely it is to be used against us. Formerly we worried mainly about Russia but now we have to be concerned about North Korea and Iran. A Scud missle with a nuclear weapon on it could be launched from a container ship 100 miles off-shore of the U.S. The rocket doesn’t even need to be accurate, it just has to go up over the U.S. and explode. Just recently ISIS paraded what they claimed was a captured Scud missle in Syria. Meanwhile, North Korea launched more missles in July.

In fact, no less than two Congressional Commissions (2004 and 2008), a National Academy of Sciences report and other U.S. Government-sponsored studies have raised heightened concerns about this issue. All found that the EMP threat poses a significant and existential threat to the United States. Ultimately, such a threat extends to the rest of the world; a failure of the U.S. banking, economic, and national security systems would quickly have enormous ramifications across the rest of the planet.

In June of 2013, Graham, Cooper, and other experts concerned with the EMP threat wrote a highly detailed letter outlining the EMP threat and ways to protect against it. This letter – from the Foundation For Resilient Societies – was addressed to the White House as well as to the Secretaries of Defense, State, Energy, and Homeland Security, as well as a host of other federal agencies. A year later, the Foundation has yet to receive a response.

Why is this so important?

Because a single missile with a warhead that actually doesn’t have to be all that large, has the potential to take out the U.S. power grid, destroy our electronics networks, and create an existential crisis like nothing the world has ever witnessed.

It is possible that a nuclear EMP may never happen where you live.

On the other hand, a severe solar storm that could destroy most of the world’s power grids including the United States for a period of years appears nearly inevitable at this point.

Protection against the damage of a severe solar storm could be done easily and rather inexpensively by the electrical utilities; however it is not being done, and there are few signs that it will be done.

The bulk of your EMP protection efforts must be directed toward protecting you and your family from the results a loss of the critical infrastructures that support our everyday lives would bring.

A 2008 study by Metatech found that the time required to obtain a replacement for any one of the 370 or so largest transformers in the United States was 3 years.

The fact that the electric power grid began as a convenience, but has become a necessity for sustaining life, is both one of the most beneficial, and one of the most dangerous, facts of 21st century existence. We do not know how long the current power grid will last; but if it not replaced by a robust permanent infrastructure, in time, hundreds of millions of people will die when the electric power grid collapses simultaneously in many countries.”

Although a hardened power grid does not seem likely in the near future, the dangers to the power grid are becoming much more widely known.

So … What can we do to minimize the short-term effects of the electricity going out?

Whatever the scope of the EMP attack, the longer that you can remain at home and be fairly self-sufficient, the better things will be for you

By buying an extra can of reasonably nutritious food every week or so, you can build up a food reserve before you realize it that will last you for at least a two or three weeks, and probably much longer.

Two or three weeks of “breathing room” after a disaster can give you great peace of mind and allow you to stop, think and plan for a future course of action (while the unprepared are all in a great panic). It is even possible that some help will arrive after a week or two.

The most important thing is to store at least a two-week supply of drinking water for each member of your family.

The most important item you can have after any sort of disaster is information about what happened. If it is a nuclear EMP, though, you may now know about it right away.

The local radio and television stations are going to all be off the air.

Most of the internet will also be down.

There might be some telephone service if you are very lucky, but anyone that you would call probably won’t know any more than you.

The only way that you will get any timely information will be by listening to broadcasts originating on other continents using a battery-operated shortwave radio.

Even if you have a shortwave radio though it is likely to be knocked out by the EMP unless it is adequately shielded.

Protecting Your Electronic Devices from an EMP

To be adequately shielded, your electronic devices need to be kept inside of a metallic, shielded enclosure, commonly known as a Faraday Cage, and preferably inside nested Faraday Cage.

The term Faraday Cage has a very specific meaning in the engineering world, and few non engineers understand the difference between a Faraday Cage and a Galvanized Steel Electromagnetic Shield Enclosure.

For our purposes we will refer to our steel enclosure as a Faraday Cage.

In a nested Faraday Cage, first wrap your devices in heavy-duty foil and place the foil-covered device in a plastic bag, such as a freezer bag, and wrap that bag completely in aluminum foil.

The “nesting” procedure helps greatly in protecting against both inadvertent gaps and the possible later accidental punctures through the aluminum foil that may severely compromise the shield.

You can also purchase commercially available Faraday bags.

Of course, any antennas or power cords need to be either disconnected or contained completely within the Faraday Cage.

A properly shielded galvanized metal trash can with a tight fitting lid can be a very effective electromagnetic shield.

galvanized_trash_canThe interior of the galvanized metal trash can should be lined with some material to electrically insulate items stored inside the container from the metal exterior.

Cardboard probably works better than any other inexpensive material for this.

Liners such as plastic trash bags may be too thin for this because of the momentary high voltages that could be induced on the exterior of a Faraday Cage during an actual EMP.

Do not place any insulation at the point where it would interfere with the electrical connection between the metal lid and the metal body of the trash can.

The extra layer of shielding provided by aluminum foil on equipment that is stored on the inside may be a critical factor in a severe EMP.

On a galvanized trash can, the electrical connection between the body of the can and the lid is critical.

For this reason, use only a new galvanized trash can for this purpose.

Dents and distortions in the roundness of the lid and the upper part of the galvanized can severely deteriorate the high-frequency shielding effectiveness of the can.

Also, the lid must be kept very firmly in place for a galvanized trash can to be an effective shield.

You can use aluminum tape to seal the trash can against more advanced EMP weapons that produce a pulse with higher frequency content, but this is usually done at the cost of the convenience offered by the metal trash can.

There are other things that can be done to better seal the connection between the lid and the body of a metal trash can. A metal EMI finger stock gasket that is made for this purpose would cost about twice as much as the new trash can itself; so this is not the best option, although it is feasible if you want to spend the money.

Simpler options are to stuff steel wool or aluminum foil under the edge of the lid (after it has been closed). If you use aluminum tape be sure to use tape that is actually metallic aluminum. You can buy aluminum tape from electronics suppliers that has a conductive adhesive. Often, the conductive adhesive is not necessary unless you are trying to shield frequencies well into the upper microwave range. A good aluminum-backed tape to use for this purpose is 3M 3340 foil tape, which can be purchased at any building materials store. The 3M 3340 tape is 2.5 inches (63.5 mm) wide, which give it a good overlap for sealing the potential gaps in a metal container.

The question about using various kinds of safes as an electromagnetic shield cannot be answered because there are so many variations in construction that would affect the shielding efficiency. In particular, the electrical connection between the door and the rest of the safe is usually not very good at all. Such a safe probably has some shielding effectiveness, but in most cases, the shielding is very minimal. In general, most safes are nearly useless; but a properly prepared galvanized trash can is very effective and low cost.

Many people have tried to use metal filing cabinets as electromagnetic shields, but they usually provide very little in the way of shielding effectiveness. (The interiors can be retrofitted with wire mesh, but your efforts are usually best expended with more straightforward Faraday shields).

For more about shielding from someone who has spent his career doing electromagnetic shielding, see Donald R. J. White’s book on EMP shielding. The 3rd edition of this book has been freshly edited and completely re-written by Jerry Emanuelson. The 3rd edition also contains new material written by Jerry Emanuelson. Upcoming books will have even greater details on specific aspects of shielding for individuals and communities. The first of those more detailed books, EMP Protecting Housing and Solar, was just released in August of 2014.


Common items to keep in your Faraday Cage.

Common Items to Keep in Faraday Cage
Common Items to Keep in Faraday Cage

Shortwave radios that have hand-crank or solar power. A modern solid-state shortwave radio kept inside of a nested galvanized trash can Faraday cage is the best form of insurance for obtaining information after an EMP.

It is important to have a NOAA Weather Radio also.

A lantern that has a hand-crank or solar power.

It is important to have at least one good flashlight when the power grid is down for a long.

Although many LED flashlights are likely to survive an EMP simply because of their small size, the sensitivity of LEDs makes the survival of unprotected flashlights less than certain.

Batteries such as Energizer makes lithium batteries with a 15 year shelf life

With Duracell 9-volt batteries, the cells are spot welded together, whereas most other popular brands use a simple press-fit interconnect for the cells

Duracell Quantum batteries have a guaranteed shelf life of 10 years and have outperformed the Energizer lithium in some performance tests.

Store sealed packages of batteries in your Faraday Cage wrapped in a layer of aluminum foil.

The immediate aftermath of either a nuclear EMP attack or a large solar super storm is likely to result in a number of fires, along with the elimination of the water necessary to extinguish the fires so it is a good idea to have plenty of fire extinguishers.

Medicine is another very important thing that must be considered. If there are medicines that are required by someone in your household, it is always prudent to have an extra supply on hand

If you want to really be part of the solution, instead of part of the problem, and increase the probability that the country can return to normal within a few years after an EMP attack, then you can be prepared to become part of the new infrastructure.

The more electronics equipment that you can store within nested Faraday shielding, the better.

If you want to be able to use that electronics equipment after the batteries run down, you will need a personal power source.

A simple small electric generator that does not depend upon electronics to start or run, is always a good idea

Solar panels can be used to supply a small amount of electricity indefinitely, especially if you also have some good rechargeable batteries that match the voltage of your solar panel.

If you have something like a 50 watt solar panel, you can store it in a nested Faraday cage.

If you plan to use solar cells or battery power, you will probably want to keep a small inverter under shielding. Inverters that can step up ordinary 12 volt DC power to a few hundred watts of household AC are not terribly expensive

For information about the EMP sensitivity of solar panels, and more details on the shielding of solar panel systems, see Donald J. R. White’s new book, EMP – Protect Family, Homes & Community. That book has chapters with information about EMP protection for even fairly large solar panel systems.


The chamber of an older microwave oven is often an efficient Faraday cage in an emergency for shielding small electronic items. It is important that any microwave oven used for this purpose should have its power cord cut off close the the body of the microwave oven.

Anything that you are hoping to use as an electromagnetic shield should be tested by putting a radio inside of the shield tuned to a strong FM station – If you can hear the FM station while the radio is inside of the shield, then the shield is not adequate

Laptop computers must be well-shielded without any connections to unprotected wires

It is important to have all of the computer data that is important to you backed up onto optical media, like CD or DVD which are not affected by EMP.

For long-term storage of data, archival grade CD-R and DVD-R media are available at a reasonable price from manufacturers such as Verbatim and Memorex..

If you have a small business with too much critical data to routinely back up onto a CD or DVD you should consider looking for a data center with EMP protection and plenty of backup power.