EMP – A Basic Explanation of the Key Factors


February 24, 2016

EMP – A Basic Explanation of the Key Factors

By Dave Phelps, Chartered Engineer, C Eng. MIMech E, Eur Ing

January 2016 


I. Introduction

The following provides a basic explanation of an EMP, the Electric Supply Grid, the meaning of  “hardening the grid,” the meaning of infrastructure, and threats to the infrastructure. It also describes what has been done up to this point.

The objective is to enable you to:

  1. Have a foundational understanding of the issues surrounding an EMP (or similar) attack on our infrastructure. This will provide a platform for further study, planning, and action.
  2. Be able to explain it to others. 


II. What is an EMP?

EMP stands for Electromagnetic Pulse, also described as a Transient Electromagnetic Disturbance. It arises when a source emits a short-duration pulse of energy. Types of EMP can result from natural occurrences (lightning), modern living (e.g. an older car engine causing radio interference, electric switching, or power line surges), or military attack (nuclear EMP or non-nuclear EMP).  

A solar flare/coronal mass ejection is often described as an EMP although it’s really a GMP (Geomagnetic Pulse).  Since it acts over a minute, it’s more of a surge than a pulse.

 The two most devastating of these are a major sun disturbance and a large nuclear EMP.

The detonation of a nuclear weapon produces a number of damaging effects, including high-energy gamma radiation. It can be “tuned” to maximize gamma radiation. When the explosion occurs higher than twenty-five miles above the earth’s surface, the gamma rays interact with air molecules in the upper atmosphere/stratosphere to produce positive ions and so-called Compton electrons. Other reactions and interaction with the earth’s magnetic field lead to the EMP that causes the earth’s magnetic field to “wave,” inducing currents in conductors. This critically damages electrical and electronic equipment and systems through uncontrolled surges or pulses.  

The EMP has three components—E1, which occurs extremely fast and hits electronics; E2, which lasts a second and behaves like a lightning strike; and E3, which is like a solar GMP and affects power lines and transformers.   Generally thought to be harmless to the human body, people may not sense the EMP. However, the body operates using a huge array of electromagnetic signals and frequencies. Imbalances in these cause dysfunction and illness. Health problems may manifest over the weeks/months after the EMP event. China is said to be working on a device that does harm the body.

An originating nuclear explosion(s) would typically occur from eighty to three hundred miles above the earth. Depending on the explosion height, one to three devices are capable of disabling the whole of the USA. The nuclear devices could be positioned using missiles from hostile countries, from a ship in the Gulf of Mexico, or even a satellite. North Korea has a satellite orbiting over the center of the USA. This could be used to launch a surprise EMP attack using a thermonuclear bomb similar to those recently tested. Since the U.S. has no radar or missile interceptors facing south, it is most vulnerable to an attack from across the South Pole.

China and Russia possess EMP weapons and the means of delivering them. North Korea and Iran may also be there or close.


III. The Electric Supply Grid

Most power stations use a source of heat to produce steam and drive a steam turbine. This then drives a generator, a huge metal coil rotating within magnets. The electricity induced within the coils is then made available to domestic, commercial, and industrial users. Coal, oil, natural gas, or nuclear reaction are typical sources of heat. Alternatives to heat-driven steam turbines are hydroelectric power (falling water) and wind power. Solar panels convert sunlight directly to electricity.

The electricity is typically produced at 25,000 volts and transmitted to sub-stations (perhaps many miles away) at up to 400,000 volts (400KV) or even higher. Energy losses are lower at higher voltages. Massive EHV (Extra High Voltage) step-up transformers are used to supply higher voltage electricity to the overhead or underground transmission lines. Step-down transformers reduce the voltage at sub-stations. The local network also uses transformers to supply factories, office buildings, and homes (40% of total). Different voltages are used for different applications. The final step-down is pole-mounted transformers along our roads providing us with 220/110 volts stepped down from say 2,400 volts.

In South Carolina alone there are approximately eighty power stations producing from one megawatt to 2666 megawatts (or 2.666 GW). One megawatt is one million watts, which would power ten thousand one hundred watt lightbulbs. One gigawatt is one thousand megawatts.

The nation and the state interlink power stations to meet demand fluctuations and provide back-up. This involves multiple, complicated, and highly sophisticated computerized control systems, often referred to as Supervisory Control and Data Acquisition (SCADA).

The U.S. National Grid has expanded in a piecemeal way over the decades. Many components, including major transformers, are nearing the end of their design-life. The electric grid is fragile and vulnerable.


IV. Consequences of a Major EMP Event

A vivid description of the aftermath of a large EMP event is in Bill Forstchen’s book One Second After.  It graphically describes an EMP’s devastating effects and provides reasoned thinking on organizing and dealing with moral issues after an event. It also highlights preparations that should be made before an event. Congress has recommended that everyone read it. Below are some highlights:

An EMP’s effect is fast.

While losing all our electronic equipment, including computers, cell phones, and most of our cars/other transport would be severely disruptive, the biggest disaster would be losing the electric grid.

An EMP would stop our “just in time” (little storage/back-up) economy—flow of food, water, medicine, fuel, heating, and sewage. Transportation, communication, banking, and emergency services would be disabled.

70-90% of the U.S. population could be wiped out within the first year of a nationwide EMP due to lack of the basic necessities that sustain life, disease, and widespread civil breakdown.

The most critical components within the grid are the major transformers and the SCADA. The grid could be down for months/years. However, all components of the grid, including generator rotors and smaller transformers, must be investigated for vulnerability. Input is needed from electric grid technical experts regarding vulnerability and possible fixes.


V. What’s Involved in “Hardening the Grid”?

“Hardening the grid” means protecting the grid from the effects of an EMP and other possible attacks, including coordinated small-arm attacks.

Well-known hardening devices and methods include huge Faraday cages, surge arrestors, chokes, filters, blocking devices, upgraded cabling, and other technology. Basic components include resistors, capacitors, and thyristors. These also protect against worst-case cyber scenarios, such as computer viruses that manipulate or collapse the grid by shutting down the SCADA.

Physical protection must also be installed around key items such as transformers.

The power industry has shown little interest in hardening the grid. It seems that the power companies, their regulatory body, FERC (Federal Energy Regulatory Commission), and trade body NERC (North American Electric Reliability Corporation), have mutual financial interest in not increasing the reliability of the grid.

The Congressional EMP Commission estimates robust protection of the national grid would cost a one-time payment of two billion (the annual foreign aid to Pakistan). FERC themselves have estimated that the extra cost to the average utilities customer to harden the grid would be twenty cents per year. Resistance is political as well as financial. Approved bills to protect the infrastructure have been blocked before implementation.

Even with the electric grid fully hardened, it is of limited value unless the other key utilities—water, natural gas, communications, and sewage—are also hardened or made capable of functioning in a primitive fashion (i.e. with pumps/compressors operated manually without electronic controls and instrumentation).

Nuclear plants need special consideration in the event of an EMP. This includes failsafe control of the reaction and provision of cooling water to the “turned-down” nuclear core and spent fuel pools.

The total cost of ensuring a primitive but functional infrastructure will likely to be much more than two billion—but unquestionably worth spending!   

We’ll need “islands of recovery” with power already in place.

Maine, Texas, Virginia, and other states are at least talking about steps to protect their electric grids. One state could effectively harden its grid without adversely affecting neighboring states.

Russia and China are said to have hardened their grids.


VI. Other Threats to the Infrastructure

In this paper, the term “infrastructure” is used to describe the electric supply grid and the other main public services, such as water, natural gas, sewage, and communications.

Hacking and malicious viruses are other serious threats to the U.S. infrastructure. 

Corporate Risk Solutions, an insurance and risk management firm, states,

The task of identifying and preparing our national grid systems for this threat is even more Herculean because of the technical ability and versatility of known terrorist organizations and cyber attackers. In al Qaeda for example, some of the members of the group are well-trained, attaining some of the highest levels of education in these fields.

In 2013, gunshots from an attack at a power station in California cut fiber optic cables and disabled transformers. This could have been a trial run for a more serious attack.


VII. What is being done about it and by whom?

NORAD (North American Aerospace Defense Command) has moved its headquarters back to an underground base in Cheyenne Mountain, Colorado to protect it from an EMP, but little has been done to protect the civilian population. The U.S. Department of Defense has known how to protect military systems from EMPs for fifty years.

On February 16, 2011, Congressman Trent Franks (Arizona) announced the launch of the Congressional EMP Caucus, the introduction of legislation into the House of Representatives, and HR668, the Secure High-voltage Infrastructure for Electricity from Lethal Damage (or SHIELD) Act. This was re-introduced in a related bill—HR2417. Former House Speaker, Newt Gingrich, supported Franks.

Trent Franks introduced HR3410, the Critical Infrastructure Protection Act, on October 30, 2013. Homeland Security received approval in December 2014 to implement practical steps to protect the electrical grid. Little has actually been done to date!

In December 2015, the House passed House Bill 3410, the Critical Infrastructure Protection bill that required the Department of Homeland Security to include the threat of an EMP in national planning scenarios After an eight year hiatus, the National Defense Authorization Act for 2016 reinstated the EMP Commission. Over recent years, NASA, the National Association of Scientists, and the Federal Energy Regulatory Commission have given attention to the EMP threat. We’ll watch the progress.

Pry, Cooper, and Woolsey have recently demanded that Washington prepare the nation's electric grid for an EMP, either from the sun or an enemy's nuclear bomb. They want the two to three thousand transformers protected with a high-tech metal box with spares ready to rebuild the system. Woolsey said knocking out just twenty would shut down electricity to parts of the nation "for a long time."

For over three decades, the South Carolina based High Frontier (HF) has been among the nation’s leading non-government authorities on missile defense issues including nuclear weapons. See more at http://highfrontier.org/about/#sthash.MHLkugJ4.dpuf.

Ambassador Henry (Hank) F Cooper is the Chairman of HF—Email, hcooper@azd.com. Phone—202 713 8541.

H. Scott Cooper is the Executive Director of HF—Email, Scott@HScottCooper.com, www.HScottCooper.com .  Phone—540 455 9306.

Dr. Peter Vincent Pry, a member of the Congressional EMP Commission and Executive Director of the Task Force on National and Homeland Security, is an expert on threats to the grid.

Ambassador R. James Woolsey is a former Director of Central Intelligence.

The North Carolina based Noah Foundation is a non-government organization dedicated to the protection of the power grid against solar, cyber, and terrorist attack—www.thenoahfoundations.com

The South Carolina Fort Mill Oak Initiative Chapter —EMP Team has reached out to a number of non-government EMP groups, Congressmen, nuclear specialists, and other technical specialists.  They are assessing the responses.


Final Note

This paper is a work in progress. Any thoughts, corrections, or clarifications are appreciated by the South Carolina Fort Mill Oak Initiative Chapter —EMP Team. 

For a current status of the South Carolina Fort Mill Oak Initiative Chapter —EMP Team’s work, contact The Oak Initiative at office@theoakinitiative.org or 803.547.8217.

For further information or clarification on this topic, please contact the Oak Initiative at office@theoakinitiative.org or 803.547.8217.


Click here for another document regarding EMP that you can send to your Presidential Candidate and Congressional Representatives.


Dave Phelps was born in England and is a retired Chartered Mechanical Engineer (similar to a U.S. Professional Engineer). He spent much of his career in the process and oil industries and held leadership positions in design, manufacturing, operations, project management, and new product development. As a Global Product Development Manager for a Fortune 500 company, Dave developed and commercialized numerous world-class multimillion-dollar product lines. Now a U.S. citizen, Dave and his wife live in Fort Mill, SC. They have two grown daughters.

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