http://www.futurescience.com/emp/emp-protection.htmlGetting Prepared for an
Electromagnetic Pulse Attack
or Severe Solar Storm
by Jerry Emanuelson
Futurescience, LLC
© 2009-2013 Jerry Emanuelson
The science fiction writer Arthur C. Clarke once said:
Any sufficiently advanced technology is indistinguishable from magic.
This statement is commonly known as Clarke's Third Law. Many people have heard this quotation, but few people really think about its implications.
We now live in a world that is so completely immersed in advanced technology that we depend upon it for our very survival. Most of the actions that we depend upon for our everyday activities -- from flipping a switch to make the lights come on to obtaining all of our food supplies at a nearby supermarket -- are things that any individual from a century ago would consider magic.
Very few people in industrialized countries do work that is not directly assisted by electronic computers, although that computerized assistance is often quite invisible to the average person. Few people think about things such as the fact that whenever we buy some food item at a supermarket (and many others are buying the same item), the next time we go to that same supermarket, they still have about the same supplies that they had before. There are invisible infrastructures all around us that are made up of advanced technology. Most of us just take the magic for granted.
Few people stop to consider what would happen if, in an instant, the magic went away. If our advanced technology were suddenly and completely destroyed, how would we manage to survive? A nuclear EMP could make the magic go away. I hope it never happens, and I don't think that it is at all inevitable. It makes no sense, however, to be blind to the danger. It is both much less likely to happen -- and also less likely to have a catastrophic impact -- if, both as a civilization and as individuals, we are prepared for an attack on our advanced technology. A nuclear EMP would be a seemingly magical attack upon our advanced technology, the technological infrastructure upon which our lives depend.
Among all of the kinds of electromagnetic disturbances that can occur, though, it is important to keep things in perspective. It is possible that a nuclear EMP may never happen where you live. On the other hand, a severe solar storm that will destroy most of the world's power grids 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. A severe solar storm poses little threat to electronics, but would take down the most important power grids in the world for a period of years. This is a special problem in the United States, and is a severe threat in the eastern United States. So, more important than preparing for a nuclear EMP attack is preparing for all of the ramifications of a severe solar storm which would cause an electrical power outage that would, in most areas, last for a period of years. Most standby power systems would continue to function after a severe solar storm, but supplying the standby power systems with adequate fuel, when the main power grids are offline for years, could become a very critical problem.
In the mid-20th century, electricity was regarded as a convenience. By the end of that century, electricity had become something that most people literally cannot live without for more than a few weeks. This profound change has happened so gradually that very few people have even noticed.
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This is a page about some of the things that individuals can do to prepare for an electromagnetic pulse attack. I'm an electronics engineer who has been thinking about the EMP problem for more than 3 decades. I even have an ancient Radio Shack TRS-80 Model 4P that has been retrofitted with a complete electromagnetic shield. It's just a personal antique, useless for anything but a personal reminder of how long I've been thinking about this problem. That early-model personal computer didn't even have a hard drive.
I've spent much of my career working with radio and television transmitters on high mountaintops where there is a lot of lightning and other kinds of severe electromagnetic transients. Many engineers who spend their careers working in fairly benign electromagnetic environments don't realize the fragility of our technological infrastructure. On this page, I'm going to concentrate on a nuclear EMP attack, but much of this also applies to natural events such as intense geomagnetic storms resulting from extremely large solar storms.
The threat of a sudden EMP attack that causes a widespread catastrophe is certainly nothing new. Consider this Cold War era 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 silent." -- from "Nuclear Pulse (III): Playing a Wild Card" by William J. Broad in Science magazine, pages 1248-1251, June 12, 1981.
The situation would be much worse today than in 1981 due to our profound and ever-increasing dependence upon electricity and electronics for the basic maintenance of our lives. In addition, the last remnants of the pre-electrical infrastructure, and the knowledge of how to use the components of that infrastructure, is slowly and completely disappearing. Some people have said that the long-term loss of the power grid would send us back to the 19th century. That belief is quite false because we have no 19th century infrastructure and very little 19th century knowledge. A long-term loss of the power grid would send us back at least 500 years.
First: Another brief note about severe solar storms (and similar natural events), and then I'll get back to nuclear EMP. Solar storms would primarily affect the power grid, and are not likely to harm things like computers. Also, solar storms would only disrupt communications temporarily, and would not be likely to cause direct harm to communications equipment (except for satellites). An extremely large solar storm, though, would induce geomagnetic currents that could destroy a substantial fraction of the very largest transformers on the power grid (possibly over much of the world). If this happened, electric power loss due to a large solar storm would be out for a period of years and possibly decades. Unlike nuclear EMP, such a solar storm is an eventual inevitability.
The last solar storm that could have caused this level of damage happened in 1859, before the power grid was in place (although in 1921 a large solar storm, of briefer duration than the 1859 event, occurred which affected a much smaller area of the planet). The power grid has only been in place for a fraction of one percent of human history, and a really large solar storm (of the size and duration of the 1859 event) has not happened in that time. There is a general assumption that any solar event that is similar to, or larger than, the 1859 solar superstorm will simply never happen again, although there is no justification for such an assumption -- in fact, we know that this assumption is false. There is a good possibility that such a large-scale solar storm will happen in this century. If it happens in the current situation without adequate spares for our largest transformers, a large part of the worldwide power grid (including 70 to 100 percent of the United States power grid) will be down for years.
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. In a solar superstorm that affects vulnerable areas of the entire world, delivery times could easily be much longer. The United States, which for many years had no capability to manufacture those transformers (and which is just beginning to regain that capability), will be at the end of a very long waiting line. Since such a expansion of transformer manufacturing capability requires a lot of electrical power, the capability cannot be developed after an electromagnetic catastrophe. The capability has to be developed before there is an actual critical need. In the past two years, two United States companies have begun the process of expanding into the large transformer business, but it will take a considerable length of time before a reasonable number of spare transformers can be manufactured.
Because of the inevitability of a large solar superstorm, we have to accept the fact that the current electric power grid upon which our lives depend is only a temporary infrastructure. This temporary infrastructure has served us very well, and we now have entrusted our very lives to it.
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. How such a collapse occurs is very well known, and the methods to either prevent it, or to have spare transformers in place to fairly quickly repair it, are also well known. Although these preventive measures would not be terribly expensive, they would take some time to put into place; and those things have never been done.
Provisions for insuring islands of power production within the country that would prevent millions of deaths could be put in place fairly quickly, and much less expensively, but this also has never been done -- or, until recently, even been seriously considered, except by the few scientists and engineers who have seriously studied the fragility of the electric power grid. There are finally signs, in 2013, that this situation is beginning to change, but the process is very slow.
I am repeatedly asked about "faraday cages" for solar storms and protection of automobiles against solar storms. I must repeat that this is an area where solar storms and nuclear EMP are very different. Solar storms only produce something similar to the E3 component of nuclear EMP. "Faraday cages" are not relevant for solar storms for anyone at ground level (unless you are planning to launch a satellite). Solar storms will not destroy your car, (at least not any of the solar storms that have occurred in the past million years). If you own an electric car, though, it may be wise to avoid charging it during an active geomagnetic storm.
Many people who say that they have off-the-grid power systems, however, are interconnected to the power grid in order to sell their excess power back to the grid. From an EMP or solar storm standpoint, this presents the worst of all possible worlds. Such an interconnection exposes a so-called off-the-grid system to all of the dangers of the power grid.
Even though solar storms primarily affect the power grid, customers can communicate the importance of EMP and solar storm protection to their local electric utilities. Devices such as the SolidGround system made by Emprimus can be installed by local electric companies on all of their large transformers that are connected to very long lines.
Although a major electromagnetic disturbance that would destroy large parts of the electrical grid is almost inevitable in the next century, it is important to keep things in the proper perspective. There is a reasonable chance that people will come to their senses in time, and have the electrical power grid protected before such an event happens. 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.
Another encouraging trend is the fact that far more people are prepared to be self-sufficient for at least a few weeks than was the case just a few years ago. The greater the number of people who have made at least minimal preparations for a disaster, the smaller will be the overall impact of the disaster.
Even apartment dwellers on a very low income can have a level of preparedness that will be of significant help. By buying an extra can of reasonably nutritious canned food every week or two, you can build up a food reserve -- before you realize it -- that will last you for at least a week or two, and probably much longer. A week or two of "breathing room" after a disaster can give you great peace of mind and allow you to stop and think and plan for a future course of action (while the unprepared are all in a great panic). It is even possible that some additional help will arrive after a week or two. The most important thing is to store at least a two-week supply of drinking water. There are many plastic containers of all sizes that can be stored in a closet that won't take up an excessive amount of space.
One kind of convenient containers for water storage in small spaces are the one gallon polypropylene plastic bottles that are used for Arizona brand teas. Although these plastic containers are marked with the Resin Identification Code 5 or 7, the Arizona Beverage Company web site states that (at least, as of July 2012 and earlier) the plastic does not contain any bisphenol-A in the container, so they should be safe for long-term water storage. These one-gallon plastic containers with screw-on plastic lids should be a convenient method of water storage for many people. Do not keep the water in storage for a very long time without refreshing your supply with new water occasionally, though. There are larger containers that are made for long-term water storage for those who have the storage space for a longer-term emergency water supply.
What just happened???
The most important piece of information you can have after any sort of unusual electrical event is information about what happened. If there is a bright flash in the sky at the same time that the power goes off, and you've been worried about nuclear EMP, your first reaction may be to assume the worst. There are many other events, however, that can cause a power outage.
If it is a nuclear EMP, though, you will want to know about it right away, and 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.
If you have a shortwave radio, it is likely to be knocked out by the EMP unless it is adequately shielded. To be adequately shielded, it needs to be kept inside of a complete metallic shielded enclosure, commonly known as a faraday cage, and preferably inside nested faraday cages. A faraday cage is an total enclosure made out of a good electrical conductor such as copper or aluminum. (Steel also works well, but it is more difficult to make a total enclosure with steel.) Large faraday cages can get extremely complicated. For small portable electronics, though, completely covering the electronic equipment in aluminum foil makes an adequate faraday cage around the equipment. The foil covering needs to be complete, without any significant gaps. Wrap the device in plastic or put it in an insulated box before wrapping the covered device in foil. (Otherwise, the foil may simply conduct the EMP energy into the device more effectively.) A single layer of foil may not be adequate. In order to enclose the equipment in a nested faraday cage, place the foil-covered device in a plastic bag, such as a freezer bag, and wrap that bag completely in aluminum foil. If you really want to protect the equipment against a large EMP, add another layer of plastic and foil. The layer of plastic needs to be the thickest plastic bags that you can easily find. (They don't need to be terribly thick, but do try to find some heavy-duty bags.)
Just adding many layers of foil directly on top of foil won't do as much good, due to what is called "skin effect." I won't bother to explain skin effect here, but you can look it up if you're curious. Don't worry too much about skin effect, though. I only mention it here because many people have the misconception that when it comes to shielding, the thicker the better -- and this is definitely not true after a certain thickness is reached. Layers of shielding separated by insulation works much better. As a practical matter, though, wrapping with 2 or 3 layers of foil helps to assure that you actually have a good shield around the equipment.
Of course, any antennas or power cords need to be either disconnected or contained completely within the faraday cage.
One question that arises frequently is whether a gun safe or a galvanized trash can makes an effective faraday cage. Technically, it may not be correct to call either of these a faraday cage because they are not constructed of the best electrical conductors. A galvanized metal trash can, though, can be a very effective electromagnetic shield. The interior of the body 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 during an actual EMP.) Do not place any insulation at a point where it would interfere with the electrical connection between the metal lid and the metal body of the trash can. It would be a good idea to wrap items placed inside the metal trash can with a layer of aluminum foil in the "nested faraday cage" manner described above. It is important to remember that a galvanized trash can, by itself, is usually an imperfect shield. It may be good enough for many purposes, but 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.
The question about using gun 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. Such a safe probably has some shielding effectiveness, but in most cases, the shielding is very minimal. In general, though, gun safes are nearly useless while properly prepared galvanized trash cans are very effective.
Many people have tried to use metal filing cabinets as electromagnetic shields, but they usually provide very little in the way of shielding effectiveness.
For more about shielding from someone who has spent his career doing electromagnetic shielding, see Donald R. J. White's book on EMP shielding.
You'll need to keep plenty of batteries on hand for your radios. There are some models of shortwave radios that have hand-crank or solar power, but those "emergency radios" that I've tried don't have very good shortwave reception (although, as explained below, many inexpensive shortwave radios could suddenly become very adequate after an EMP event). A common complaint about radios that use hand-crank power is that the hand cranks are not very sturdy, however the radios will continue to function by using conventional battery power (or solar power if it is available.) If you do use the hand crank on an emergency radio, though, do not treat the hand crank too roughly. I still recommend keeping plenty of batteries on hand.
Energizer makes lithium batteries with a 15 year shelf life. Although small batteries were not damaged during the 1962 high-altitude nuclear tests, it would be wise to wrap each sealed package of batteries wrapped in a layer of aluminum foil. Future EMPs may be much larger than the 1962 events. Also, battery technology is evolving and the sensitivity of newer types of batteries to EMP is unknown (although the cylindrical batteries tend to provide a certain amount of shielding just due to the way that they are constructed.). I generally prefer Energizer batteries for cylindrical batteries (AA, AAA, C and D sizes) and Duracell for 9-volt batteries. The 9-volt batteries contain 6 internal cells in series. In the Duracell 9-volt batteries, the cells are spot welded together, whereas most other popular brands use a simple press-fit interconnect for the cells. The Duracell spot-weld method generally makes for a much more reliable connection in this type of battery.
The idea behind having a shortwave radio is to be able to directly receive radio stations on another continent that has been unaffected by the EMP. The radio that I like best of the portable, and not too expensive, receivers is the SONY ICF-SW7600GR. This model is not cheap, but you can usually find it for at least 25 percent below its "list price."
Another good shortwave radio for the price is the Grundig Traveller II Digital G8. This Grundig radio is much less expensive than the SONY ICF-SW7600GR. You can usually find the Grundig G8 for around 50 U.S. dollars. In using the Grundig radio recently, my only complaint was that it seemed to be much more susceptible to electrical noise than many other shortwave radios. Electrical noise is always a problem when listening to distant stations, but, of course, in a post-EMP situation, electrical noise would cease to be a problem.
Grundig also makes a somewhat better radio known as the S350DL, that sells for about 100 U.S. dollars. This radio is larger, and many people find it easier to handle. It also has a number of features, such as bandwidth and RF gain controls, that are very difficult to find on other radios in this price range. The tuning on the S350DL is analog, but it has a digital readout. Some of the annoying aspects of the tuning dial in earliest models of this radio have been corrected in current versions.
The National Geographic Store sells the Grundig S350DL radio, which is pictured at the bottom of this page.
Many people have legitimate complaints about nearly any shortwave radio that can be purchased for less than 300 U.S. dollars. Those complaints are often valid if the radio is to be used frequently in today's high levels of electrical noise and radio frequency interference. In a post-EMP situation, or any situation where the regional electric grid goes down, the situation will be very different.
Many people have bought or kept old vacuum tube radios for use after an EMP attack. Although vacuum tubes are thousands of times more resistant to EMP than transistors (and discrete transistors are much more resistant than integrated circuits), other components of vacuum tubes radios can be damaged by EMP. In fact, vacuum tube radios actually were damaged in 1962 high-altitude nuclear tests. Vacuum tube radios also have the disadvantage of requiring much more power than solid-state radios, and electric power will be a rare commodity after a nuclear EMP. Although a vacuum tube radio would have a high likelihood of coming through an EMP event undamaged as long as it was turned off and not connected to an antenna, a modern solid-state shortwave radio kept inside of a nested faraday cage is the best form of insurance for obtaining information after an EMP event (and it is preferable that the shielded radio also be stored inside a galvanized trash can as mentioned above).
(Many people don't realize that most vacuum tube radios still in existence have an early solid-state device called a selenium rectifier that is quite vulnerable to EMP damage. Although replacement selenium rectifiers are still sold for old radios, they are difficult to find, and you would probably find them to be completely impossible to get after an EMP attack.)
One important misconception about electromagnetic shielding is the common belief that it should be "all or nothing." When it comes to critical small spare items like an emergency radio, it is important to go to some extra trouble to insure the best shielding possible. Simple small nested faraday cages are so simple and inexpensive that you might as well make sure that a few items are very well shielded. When it comes to less critical items, though, such as items that you use frequently, a less-complete electromagnetic shield could easily make the difference between having equipment that survives an EMP and equipment that does not survive. It is a very common misconception that certain items must have military-grade shielding and other items are nothing to worry about at all. Real world electromagnetic disturbances are much more messy than that. (See the either-or myth on the EMP Myths Page.)
A nuclear EMP will severely disrupt the upper atmosphere for a while, so it could be several hours after an EMP before you get decent shortwave reception with any radio, but that will be long before you could get information from any other source. If you're in the United States, you may be able to get emergency information from a local NOAA Weather Radio station. I believe that a few NOAA emergency transmitters are EMP-protected, but most are not. Repairs to many of these transmitters may be able to be made by military personnel, who can also supply emergency power to them for a while, but that emergency power may not last very long. If you're in the United States, though, it is important to have a NOAA Weather Radio. These radios really are inexpensive, and whenever the NOAA transmitters are working, they can provide local information that is critically important. Like your shortwave radio, an emergency NOAA Weather radio needs to be kept in a nested faraday cage until you need it. NOAA Weather Radios could be especially important in the case of a large solar superstorm, where the radios would probably continue to work and give information, even though much of the power grid could be out for years.
Many people severely underestimate the need for information in any kind of a disaster. In recent examples of long-term disasters (such as the breakdown of civilization in the former Yugoslavia in the 1990s), many people actually died while undertaking risky activities in order to obtain information. Many 21st century humans have an addiction to information that (although it has greatly improved their standard of living) would cause them to take even greater risks than people did only a generation earlier. The important thing is to think about the importance of information well before any sort of a disaster happens.
If you have a spare laptop computer, it can also be stored in nested faraday cages, just like your radio.
LED and CFL lights: LED lights (and, to a lesser extent, compact fluorescent lights) can be very useful for post-EMP use because of their efficiency at a time when very little electricity may be available. Both LED lights and CFL lights, though, are very sensitive to EMP.
LED lights are solid-state diodes that are made to conduct electricity on one direction only. In the case of LED lights, the LED itself has a very low reverse breakdown voltage. Most LED lights will handle a fairly large voltage spike in the forward direction, but not in the reverse direction. LED lights are currently the most efficient form of lighting that is available. LED lights also can last for a very long time. I know of one case where a device that I built at a television transmitter site in 1980 has some of the older (1970s) type of LED indicator lights that have been operating continuously for more than 30 years.
Compact fluorescent lights can probably be stored without any kind of EMP protection because the base of the light is so small that they are unlikely to pick up enough voltage for the imbedded transistors to be damaged. CFL bulbs are almost certain, however, to be damaged if they are in a socket at the time of an EMP since they have two switching transistors embedded into the base of the CFL. These switching transistors, although they are out of sight, would very likely be damaged by high voltages picked up by any wiring external to the CFL device itself.
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. Also, some LED flashlights contain additional sensitive circuitry. Because of the importance of having at least one good flashlight when the power grid is down for a long period of time, it would be a good idea to store at least one LED flashlight in a nested faraday shield.
