Are Generators EMP Proof?

Whether a natural phenomenon or a manufactured event, the threat of an EMP has the potential to disrupt services and bring upheaval to our modern electronic-dependent society.

If nothing else, recent times have shown us that life is unpredictable, and events that seem improbable could conceivably be our reality and turn our world upside down in the blink of an eye. Preparing as best we can is the best action we can take. With this strategy in mind, how would a portable generator stand up to an EMP event?

A generator is not EMP proof. The motor will survive such an event, but the electronics that control the voltage output will be rendered inoperable by a significant EMP event. The best way to protect your generator is with a faraday bag if it is a small unit or a faraday cage for larger units.

An EMP has been an event that science fiction writers have considered since 1965 that could potentially bring our civilization to a grinding halt and place us back in the dark ages. Power services will fail, as will everything run by computers and electronic intelligence. Can a portable generator withstand an EMP, and would it be a viable device to provide power after such an event?

What Is An EMP?

An EMP is an electromagnetic pulse, and it can have a natural source and a manufactured source. An EMP that most of us are familiar with is lightning. Lighting does not have to directly strike your house to cause damage to your electronic and electric appliances. A nearby lightning strike produces a localized EMP that damages electronics.

An EMP can be caused by a high voltage source or by a magnetic force. Solar flares from our sun can generate EMPs that can take out our satellites and damage electronic infrastructures on the earth’s surface.

Other sources of EMPs are nuclear weapons or geomagnetic storms generated by the earth’s magnetic field.

Now we understand the potential source of an EMP, what are the implications for your generator?

Will a Generator Withstand an EMP?

Generators use relatively simple fuel-driven motors, which produce electricity. The produced electricity is controlled and filtered to supply it in a usable and predictable form at the power outlet of the generator.

The generator’s motor does not have much in electronics and engine management since these engines are designed for rough, rugged work. There are usually no computers and electronic fuel injectors on these machines that an EMP could potentially affect.

The fuel delivery system is usually a simple carburetor rather than a fancy fuel injection system. The motor of the generator will, therefore, in all likelihood, survive an EMP event intact.

The problem comes into play with the electronics that filter the electricity into a useable form. These electrical components filter out spikes and power fluctuations from the generator and regulate the generator’s voltage. They are then responsible for output clean AC or DC power that is suitable for running modern, sensitive electronic devices.

These components that control the electricity produced by the motor are susceptible to an EMP and would sustain damage from such an event. Like every electric or electronic device the EMP reaches, the components, circuit boards, wires, and fuses in your generator will fry.

So, if a generator is not EMP-proof, what can you do to protect your generator so that you will be able to produce power for your home after an EMP event?

How to Protect Your Generator From an EMP

There are essentially only two main ways to protect your generator from an EMP so that it will still function after the pulse has passed.

  1. Using a faraday bag for smaller generators
  2. Or using a faraday cage for larger generators

Let’s take a look at both options, as well as a few other considerations that you should think about while prepping for an EMP.

A Faraday Bag

The first one is by storing your generator in a faraday bag that has been specially designed to disperse EMP energy around sensitive electronic devices and equipment.

Faraday bags are produced by companies such as Mission Darkness that specialize in this kind of product. The bag has a waterproof outer coating, and embedded in the bag is a conductive material that will distribute the pulse around the equipment stored inside, thus shielding it from the EMP.

The downside of this type of bag is that it is relatively small and will only be suitable for small portable generators. You will also not be able to run the generator from within the bag since the heat from the generator will damage the bag or cause it to combust.

A Faraday Cage

The other alternative, and probably the most practical, is to house your generator in a purpose-built enclosure that incorporates a faraday cage around the generator.

The principle of a faraday cage is to have a continuous layer of conductive material, usually metal, that surrounds the device you want to protect. The generator would need to be completely isolated from the cage, so it would need to stand on a thick rubber mat.

The conductive layer can be a wire mesh that completely encapsulates the generator. You can build it into concrete floors and walls. The door to the enclosure would need special attention to make sure it connects to the conductive material on all four sides to avoid any gaps where the pulse could pass through.

The best way to construct the cage is with multiple layers of conductive material separated by an insulating material such as plastic or rubber.

You would need to isolate the cables that come from the generator since the pulse could flow through the cables and damage the generator. Circuit breakers and fuses would be necessary between the generator and the cables connecting to your appliances.

The preferred situation would be for your generator to be disconnected and not running at the time of the pulse, in which case the faraday cage will do its job and disperse the pulse around the generator.

If the generator is plugged in and running, then the faraday cage may limit the damage, but there is no guarantee that it would make it unscathed through the event.

The ideal would probably be to have a backup generator that is completely disconnected and isolated within a faraday cage. You can then run your main generator with confidence that if an EMP event occurs and fries your main generator, you have a backup unit in place to use once the danger has passed.

Other EMP Considerations

An EMP will significantly impact society and services and could hamper your ability to run your generator, even if it survives the initial EMP.

You need fuel to run your generator, and an EMP will render fuel pumps at gas stations unable to pump gas. There will also be a breakdown in the delivery of fuel, so once the gas stations run out of gas, you will not be able to power your generator. 

Therefore, you will either need to have a stockpile of fuel, or be able to produce your own, such as bio-diesel, if you have a diesel-powered generator.


An EMP event is a complex occurrence to protect against, and even though it may be an unlikely event, there is no guarantee that it will not occur. Preparation is the key to ensuring that your electronic and electric devices will survive.

This may require the need to have backups or spares of critical devices and appliances that may help you live as close to normal a life as possible. These devices would all need to be in permanent storage protected against an EMP to ensure they will be in working order after the pulse or series of pulses.

While the preparations to protect your equipment from an EMP may seem to be extreme, you will be happy that you went through the effort to do it when you can produce electricity for lighting, heating, refrigeration, cooking, and communication in a post-EMP society!


Hubert Miles

I've been conducting home inspections since 2002. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and an FHA 203k Consultant. I started to help people better understand whole-house and portable generators.

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