According to the Congressional EMP Commission, it would cost around 2 billion dollars to shield the country’s power grid against an EMP. The technology is there, it has always been there, but politics get in the way according to the commission (Peterson, 2014).
Size Does Matter
An EMP can be localized, for example, a ground detonated nuclear device will create an Electromagnetic Pulse that affects a certain area, states miles away would not be affected and thus any shielded equipment you have could be used to monitor for information and used to communicate with others outside of the area.
The size and scope of the attack or occurrence is important. One problem is you would not likely have any warning so a state of preparedness would have to be maintained at all times.
An atmospheric detonation, depending on the size of the device, could shut down a large portion of the country. Multiple detonations of this type would literally destroy the entire power grid. Even if you were prepared what good, does a radio or a cell phone do you if there is no one on the other end? The systems needed to operate the devices would be destroyed as well, so any devices you did shield would become paperweights in a matter of seconds.
Computers and anything that operates from a computer would be disabled. This includes cell phone service providers and of course the Internet. Your car may be shielded, but where would you drive too, and for how long and how far because fuel cannot be pumped and the highways would be littered with stalled vehicles.
Faraday Cage Invented By Michael Faraday in 1836
To err on the side of caution, you would want to shield certain equipment, because you simply do not know what may happen and whether you can use a device after an event. Faraday cages will block external electrostatic fields and electromagnetic radiation.
Electromagnetic Radiation will seek earth, typically called earth ground. Your home is grounded usually by a copper rod driven at least ten feet down and then connected to the copper plumbing in the home.
Electronic equipment can be shielded by placing it ten feet or more underground, (some may say only two feet but why take a chance 10 feet is better) under soil to be more precise or you can shield it aboveground using what is commonly called a Faraday cage.
A microwave oven by design is essentially a Faraday cage in reverse. It is designed to keep the radiation contained inside so thus would work to keep it out as well. You can of course make your own cage, but it must meet certain requirements to provide protection. The microwave must be unplugged from the homes’ electrical system for it to provide protection.
- The enclosure must be conductive (does not have to be solid can be wire mesh) an elevator for example is a Faraday cage of sorts so that is why cell phones lose their signal inside of one
- The material shielded must not touch the sides (must be insulated from the cage) once inside the cage
Should the cage be grounded, (many examples online do not show it being grounded some do however). One expert will say yes another will say no.
Large cages designed to shield entire areas, garages for example, probably should be grounded by a standalone ground not connected to your home’s copper wiring. Cages made to shield small devices if constructed properly do not necessarily need to be grounded.
Technically speaking if a cage is grounded, it would ensure the excess charges will go to the ground instead of the outer face, so the inner face and the inner charge will cancel each other out, and the rest of the cage will retain a neutral charge.
A shopping bag lined with aluminum foil can act as a Faraday cage and it is not grounded. This ad hoc cage is often times used by shoplifters to get RFID tagged items past the detector. It is all a matter of degrees and the intensity of the EMP.
Rooms that house MRI machines are designed as a Faraday Cage. Faraday cages are also used to shield against electronic eavesdropping.
You can shield your devices but in the end, you have to ask yourself will they do any good, will they help you survive. Learn to do things without the benefits of electronic components, gas operated equipment and so on.
Fuel would soon be depleted so your chainsaws and gas-operated tools will be so much clutter under foot in a few days or weeks anyways so learn now how to do task by hand instead of trying to learn in the midst of the crisis.
Peterson, J. (2014, April). Retrieved 2014, from http://watchdog.org/138940/solar-flare-emp/