GRID SECURITY:
A Fact Sheet on GMDs vs. EMPs
Protecting the nation’s electric power grid and ensuring a reliable and affordable supply of energy are top priorities
for the electric power industry. The power grid is a complex, interconnected network of generation, transmission,
distribution, control, and communication technologies that can be impacted by natural events—including severe
storms, earthquakes and geomagnetic disturbances (GMD) like those caused by solar flares—and by malicious
events, like cyber or physical attacks.
The electric sector’s approach to protecting critical assets is known as defense-in-depth, which includes
preparation, prevention, response, and recovery for a wide variety of hazards to electric grid operations. The
industry recognizes that it cannot protect all assets from all threats. Instead its priorities are to protect the most
critical grid components against the most likely threats; to build in system resiliency; and to develop contingency
plans for response and recovery when either man-made or natural phenomena impact grid operations.
The industry works in partnership with other grid owners and operators; the North American Electric Reliability
Corporation (NERC); relevant federal government agencies, including the Department of Energy (DOE), the
Department of Homeland Security (DHS), the FBI, and the Federal Energy Regulatory Commission (FERC); and
state and local law enforcement agencies.
Industry Activities on GMDs and Electromagnetic Pulses (EMPs)
The electric sector, through NERC’s standards-setting process and in response to FERC’s orders, is developing
mandatory and enforceable reliability standards to help protect the grid from the impacts of GMDs. The first phase
of these standards was approved by FERC on June 19, 2014, and will become enforceable on April 1, 2015. The
second-phase GMD standards are currently under development and must be filed with FERC by January 2015.
While standards are beneficial, the industry must rely on the federal government to defend against hostile nationstates or attacks on the homeland, especially in the case of nuclear threats and the associated EMPs. An EMP is a
blast of electromagnetic energy that can disrupt—if not destroy—electronic devices within an affected area. Manmade EMPs are produced by nuclear weapons or other devices designed to create intentional electromagnetic
interference. The impact of an EMP from a high-altitude nuclear explosion or even a smaller nuclear device affects
more than just the electric sector. Other critical infrastructures that utilize microprocessors are also vulnerable.
Any activity that relies upon devices containing integrated circuitry—such as industrial process control systems,
hospital equipment, and transportation and telecommunications systems—could be affected by an EMP attack. As
such, the responsibility for protecting the United States from a national-level event like an EMP attack should fall on
the country’s defense intelligence and military services, not on individual critical infrastructure providers.
Grid Security: A Fact Sheet on GMDs vs. EMPs
GMDs and EMPs Are Not the Same Thing
In discussing the potential effects of these phenomena on the grid, there is a significant difference between
naturally occurring GMDs and man-made EMPs (as illustrated in the table on the following page).
Industry-Government Coordination
Addressing threats to the grid requires a coordinated approach that leverages government and industry resources.
The electric and nuclear sectors are the only critical infrastructure providers with mandatory and enforceable
standards to help protect the reliability and security of the bulk power grid assets they own and operate. These
standards cannot be designed specifically to address every potential vulnerability and threat. This is one of the
reasons why continuous close coordination between government and industry is critical.
Government and industry already work closely on matters of critical infrastructure protection. The Electricity
Subsector Coordinating Council (ESCC) is a beneficial forum for utility executives and senior Administration officials
to discuss national security policy issues that can impact the grid. Coordinating efforts and bringing together
government and industry expertise help to improve the security posture of the industry and the nation. Both the
public and private sectors have unique roles, responsibilities, and capabilities; leveraging each of these in a
coordinated way is imperative. EMP is the type of emerging issue that the ESCC was established to address at the
policy level engaging with DOE, DHS, the Department of Defense, and other federal agencies that have unique
national resources beyond the capabilities of the private sector.
Security Is and Always Will Be an Evolving Issue
As utilities invest in new facilities or upgrade existing ones, they incorporate protections against new and evolving
threats to bolster their overall risk-management profiles, taking into account broader consumer protection and riskmanagement factors.
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Grid Security: A Fact Sheet on GMDs vs. EMPs
GMDs – Grid Resilience
EMPs – National Security
Geomagnetic disturbances or solar storms are initiated
by events on the surface of the sun where ejected
masses of electrically charged particles of varying levels
are hurled toward the Earth, creating the potential for
Earth-based disturbances due to their interaction with the
Earth’s magnetic field. When the particles interact with
the Earth’s magnetic field, especially in certain
geographic regions, they can cause ground-induced
currents (GIC) and other potentially disruptive
phenomena.
An EMP is a blast of electromagnetic energy that can
disrupt—if not destroy—electronic devices within an
affected area. While other devices can produce an
EMP, EMPs generated by a high-altitude nuclear
explosion are the only ones that pose a widespread
potential threat to the reliability of the electric power grid
as a whole or within a region.
In May 2013, FERC Order No. 779 directed NERC to
develop reliability standards to address the potential
impact of GMDs on the reliable operation of the bulk
electric system.
Within the range of EMPs, there are variations in
terms of impacts and responses. Just as the
consequences and likelihood of each of these
threats vary, so, too, does the approach to
protecting the electric grid against them.
The federal government bears the responsibility of
protecting the country against nuclear devices.
• The first standard requires applicable registered
entities to develop and implement operating
procedures to mitigate the effects of GMD events.
• A more localized threat could come from so-called
“suitcase EMPs” or directed energy weapons.
These types of devices may pose a threat to a single
facility or piece of equipment, but not to the entire
electric system. As with other directed weapons or
local physical threats, the electric power industry
prepares for local EMPs through its defense-in-depth
security posture, including the redundancy of grid
components, ensuring an ability to re-route power,
and establishing response and recovery protocols.
As threats to the grid evolve, so does the industry’s
security posture; resource allocation and threat
mitigation will require ongoing assessments.
• The second standard will require registered entities
to conduct initial and ongoing assessments of the
potential impact of a benchmark GMD event on their
respective systems. If the assessments identify
potential impacts from a benchmark GMD event, the
reliability standards will require the registered entity
to develop and implement a plan to mitigate the risk
of instability, uncontrolled separation, or cascading
as a result of a benchmark GMD event.
Whether planning for a traditional kinetic attack
(firearms, explosive devices, theft, vandalism), or a
directed energy weapon or solar storm, the electric
power industry employs a “defense-in-depth”
approach to grid security and resilience. Developed
over many decades of accumulated experience, this riskmanagement program focuses on preparation,
prevention, response, and recovery to deal with a wide
variety of hazards to electric grid operations.
• EMPs caused by high-altitude nuclear explosions
could have a more widespread impact not only on
the electric grid but on electronic systems far beyond
the blast range of the device. The federal
government should address EMPs from nuclear
blasts when planning for, preventing, protecting and
recovering from acts of war or terrorism on or over
U.S. soil.
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The American Public Power Association (APPA), based in Washington, D.C., is the service
organization for the nation's more than 2,000, not-for-profit, community-owned electric
utilities providing service in 49 states. Collectively, these utilities serve more than 47 million
Americans.
The Edison Electric Institute (EEI) is the association that represents all U.S. investorowned electric companies. Our members provide electricity for 220 million Americans,
operate in all 50 states and the District of Columbia, and directly employ more than
500,000 workers. EEI has 70 international electric companies as Affiliate Members, and
270 industry suppliers and related organizations as Associate Members. Organized in
1933, EEI provides public policy leadership, strategic business intelligence, and essential
conferences and forums.
The National Rural Electric Cooperative Association is the national service organization
that represents the nation’s more than 900 private, not-for-profit, consumer-owned electric
cooperatives, which provide service to 42 million people in 47 states.
July 2014