Threats to Electric Power Grid Could Result in “Black Sky Days”

The societal impact of a “Black Sky Day”—a term used by electric infrastructure security experts when discussing a collapse of the North American power grid—would be devastating, according to Dr. Daniel Baker, distinguished professor of Planetary and Space Physics at the University of Colorado, Boulder.

Baker testified before two subcommittees of the U.S. House of Representatives Committee on Science, Space, and Technology during a hearing on Sept. 10. His testimony echoed some of the same concerns R. James Woolsley, chairman of the Foundation for Defense of Democracies and former director of the Central Intelligence Agency, aired before the U.S. Senate Committee on Homeland Security & Governmental Affairs in July. During that hearing, Woolsley said that a severe electromagnetic pulse (EMP) or geomagnetic disturbance (GMD) event could result in the death of up to 90% of the U.S. population.

EMPs and GMDs

An EMP is a very intense pulse of electromagnetic energy, typically caused by the detonation of a nuclear device or other high-energy explosive device. A GMD can be caused when a solar eruption produces a coronal mass ejection (CME) that travels from the sun to the Earth.

A direct hit by an extreme CME would cause widespread power blackouts disabling everything that uses electricity. One powerful solar storm occurred three years ago, but missed the Earth by a matter of days.

“The occurrence of severe space weather impacting our nation’s infrastructure is not a question of if, but when,” Baker said.

Just as Woolsley had advised, Baker suggested that action must be taken to minimize the effect that an EMP or GMD event would have on the North American power grid. Other experts testifying before the lawmakers also warned of the U.S. electric power grid’s vulnerability.

Physical Threats

Dr. M. Granger Morgan, Hamerschlag University Professor in the Department of Engineering and Public Policy at Carnegie Mellon University, said that because the power system is spread out across the landscape, it is inherently exposed to both natural and intentional physical damage.

Morgan noted that space weather, wild fires, tornados, floods, earthquakes, tsunamis, hurricanes, and ice storms all pose natural threats. Although avoiding natural disaster is impossible, he suggested that the high-voltage power system could be made much more resilient.

Evaluating and Mitigating Risk

Richard Gordon, senior technical executive for the Power Delivery & Utilization Sector at the Electric Power Research Institute (EPRI), testified on the grid’s vulnerability to high-impact, low-frequency events, such as EMP and GMD events. Gordon said that to completely eliminate power system vulnerabilities would be cost prohibitive.

“It would defeat the industry’s objective of providing reliable, safe, environmentally acceptable, and affordable power,” he said.

Gordon suggested that EPRI supports an approach in which vulnerabilities from all threats are assessed, the impact is calculated, and cost-effective countermeasures are developed that improve transmission system resiliency. He also said that once all of the different threats have been evaluated individually, EPRI supports looking sideways to see if any mitigation strategies can be implemented to support multiple threats.

Baker referred to a 2009 study conducted by the U.S. National Academies suggesting that the total economic impact from an EMP- or GMD-type event could exceed $2 trillion. He said transformers disabled by such a storm could take years to repair or replace. For this reason, Baker advocates steps to improve the space weather prediction capability, which could allow greater advance warning for future events.

“The existential threat to our society represented by severe space weather events, especially to the national power grid, demand a major national commitment, even in these times of fiscal constraint,” Baker said.

Hackers and Other Hazards

Nadya Bartol, vice president of industry affairs and cybersecurity strategist at the Utilities Telecom Council, noted that individual hackers, activist groups, cyber criminals, and nation states also pose serious threats to the grid. She said the country is dealing with an “asymmetric threat.” Bartol offered some actions that could be taken to reduce the grid’s cyber-related vulnerabilities. Her suggestions included:

  • Increasing the supply of cybersecurity workforce personnel that understand both information technology and operational technology contexts.
  • Financially enabling utilities to upgrade or phase out their legacy infrastructure.
  • Enacting information sharing legislation that removes current barriers.
  • Supporting industry-based standardization in the National Institute of Standards and Technology (NIST) framework implementation to help integrate security considerations into current and future technologies.

Morgan referred to a 2013 attack on a 500-kV substation in California and suggested that chain-linked fences surrounding many large substations should be replaced with more robust, opaque barriers. He also said security should be increased and access limited.

Other actions that Morgan supported to increase grid resiliency included:

  • Developing a stockpile of replacement transformers for emergency use,
  • Increasing use of smart meters and microgrids, and
  • Installing light-emitting diode (LED) traffic lights with solar cell and battery backup in key transportation corridors so that emergency vehicles can avoid congestion following an event.

Aaron Larson, associate editor (@AaronL_Power, @POWERmagazine)