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Black Sky Hazards & Grid Resilience

June 15, 2021
A black sky event, then, is the black swan’s meaner uncle.

Near the end of 2019, when life was still “normal,” I began planning a live event for T&D World. The topic would cover black sky events and grid resilience, which was particularly relevant at the time. I would love to take credit for being prophetic and hitting the mark with that topic. Still, there was no way to have anticipated some of the events we have experienced since 2020, i.e., pandemic, social unrest, cybersecurity incidents, and relatively large outages from wildfires, hurricanes, and ice storms. Given the nature of critical infrastructure, I think our industry was already perhaps one of the best prepared for these types of disasters. However, 2020 has still heightened our awareness regarding the fragility and interdependencies of our modern connected world, as well as the potentially catastrophic outcomes of grid failure. More so than ever, the improbable is probable, and how we assess risk is changing. For example, last February, the power grid in Texas was a mere couple of minutes from crashing. Unfortunately, most of the public does not understand the implications. Still, many unsung heroes in the power industry work in the background to develop engineering and operational controls to keep that precise scenario from occurring.

What Exactly is a Black Sky Event?

At this point, you are probably familiar with the term “black swan” event. defines this as an unpredictable event beyond what is normally expected of a situation and has potentially severe consequences. In addition, black swan events are characterized by their extreme rarity, severe impact, and widespread insistence that they were obvious in hindsight.  

A black sky event, then, is the black swan’s meaner uncle. The Electric Infrastructure Security (EIS) Council, who coined the term, defines it as a catastrophic event that severely disrupts the normal functioning of our critical infrastructures in multiple regions for long durations. These devastating events could either be manmade or natural hazards. Examples of manmade hazards are high altitude electromagnetic pulse, intentional electromagnetic interference, cyberterrorism, physical attacks. Natural hazards include serious earthquakes, severe space weather, and hurricanes.

In a black sky event, an unprotected grid would cause an extended duration power outage and precipitate cascading, direct and indirect failures of other critical societal infrastructures. These other infrastructures include oil, gas, transportation, water, wastewater, and so on. As a result, everything we depend on will start to fail. For all practical purposes, we would be thrown back in time over 100 years.  This description begins to sound a little bit like what parts of Texas started to experience in February, doesn’t it?

Manmade Hazards

High Altitude Electromagnetic Pulse – A nuclear detonation in the upper atmosphere creates an electromagnetic pulse (EMP), a powerful, damaging electromagnetic field covering a subcontinent-scale region.

Intentional Electromagnetic Interference (IEMI, also known as radiofrequency weapons) – The pulse from IEMI devices can be higher in magnitude and frequency than EMP. However, the effective range is shorter for discrete targets. According to the EIS Council, IEMI weapons can “damage or destroy microprocessors, corrupt or wipe out data on hard drives, and could cause misoperation of relays and electrical arcing in high power system components, such as transformers.”

Cyberterrorism – Utilities are attacked thousands of times per day and must secure their systems against these threats. Federal agencies and utilities have partnered to share information and protect against this risk. According to the EIS Council, an extended power outage caused by a cyber-attack would jeopardize the functioning of hospitals, municipal water systems, and other infrastructure vital for saving and sustaining lives. It would also directly threatening state information networks and functions that are vital for the continuity of government and the delivery of essential services.”

Physical Attacks – Coordinated physical assaults on critical infrastructure could create outages with a broad geographic scope and long duration.

Natural Hazards

Serious earthquakes could cause geomagnetic disturbance (severe space weather), hurricanes, and other extreme weather events have the potential to cause power outages much more severe in terms of temporal and geographic scope than outages we have experienced in the past. “There is compelling evidence that the increase in severe weather patterns in recent decades signifies a general increasing severity in these regards, either due to periodic, heuristic factors, or to the climate change effects induced by modern society.”

Utilities have many lessons learned from previous disasters and make an array of investments to address grid resilience. In addition, regulatory commissions and other leaders are spearheading a range of initiatives to help utilities prepare and review these investments.

Join Us!

T&D World will hold a utility-led event focused on black sky hazards and grid resilience on Oct. 11-12 at the Gaylord Texas in Dallas, TX. Three tracks will explore (1) risk assessment, planning, and prevention, (2) response and recovery, and (3) technology innovations. Please visit to submit a session proposal or register for this event. After many long months without travel, I look forward to catching up with many of you!

Until next time, stay safe and healthy!

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