When Hurricane Idalia was making its way towards Florida, electric utilities there prepared for the worst. However, electric utilities lack this level of preparedness for the rare, but likely, power system events that could lead to a wide area blackout.
This lack of preparedness is partially due to a lack of accurate system models. Another issue is that electric utilities are hesitant to implement staged fault testing, a proactive measure that would significantly improve grid reliability.
By making updates to power system models based on knowledge gleaned from past wide area blackouts, and by implementing staged fault testing, the electric energy grid will be far more resilient to rare power system events.
Let’s take a closer look at how electric utilities prepared for Hurricane Idalia, and how they can better prepare to prevent wide area blackouts.
Electric Utilities Prepared for Hurricane Idalia
In preparation for Hurricane Idalia to make landfall in Florida, Edison Electric Institute (EEI) called for more than 25,000 workers from several states and the District of Columbia to be positioned preemptively in strategic locations so that they could quickly respond to power outages. Duke Energy stationed thousands of power trucks at Tropicana Field in St. Petersburg, and brought in almost 5,000 workers from sister utilities in the Midwest. Workers were prepared to assess damage and restore power as soon as the storm had passed.
Hurricane Idalia was not a worst case scenario storm; it was downgraded to a tropical storm after moving across Florida and into Georgia. Still, nearly 300,000 homes and businesses were without power after the storm hit. Luckily, power was restored to nearly all customers within only five days, likely due to electric utilities’ preparations.
Wide Area Blackout Preparation Differs from Storm Prep
Though storm preparation and wide area blackout preparation are both vital to creating a reliable and resilient grid, the two are very different. Storms are unavoidable, especially as climate change worsens and the frequency of severe storms increases. Wide area blackouts, on the other hand, are preventable.
Preparations for storms not only include bringing in workers to restore power as quickly as possible. Storm prep also involves facility design, specifically whether facilities are designed to withstand natural disasters or be quickly repaired afterwards. Electric utilities often chose to build inexpensive facilities that can be quickly repaired when damaged, though more costly facilities that can withstand severe storms may be a better choice for future construction.
Preparation for wide area blackouts also involves preparing facilities to withstand the worst, whether inflicted by severe weather, saboteurs, or electric energy shortages. Also necessary for wide area blackout preparations are updated power system models, which show how the power system will respond to worst case scenario events. Proactive staged fault testing is also vital if utilities are to be prepared to prevent wide area blackouts.
After 2003 Blackout, Models Weren’t Prioritized
Unfortunately, electric utilities do not prioritize developing models that accurately simulate rare, but likely, power system events that could lead to a multistate, wide area blackout. Very few electric utility engineers utilize electric system models, or have the time to improve them.
Often, the relevance of power system models is not understood until after wide area blackouts occur. For example, when the Northeast Blackout occurred in 2003, the subject matter experts who investigated the event stated that there was a step change in reactive power demand (vars). Subject matter experts who routinely worked with large motor applications noted that sudden changes in reactive power demand are an indication that many motors were attempting to reaccelerate at the same time.
After the blackout, electric service was restored to most of the 55 million people affected within 8 hours. Notably, there were no equipment failures that delayed recovery. The 8 hour recovery time was needed to match energy sources with customer load so that voltage and frequency remained stable. Energy control centers, such as the one in New York state, sequentially directed the energization of neighborhood substations as energy sources returned to service. Some energy production facilities, such as Indian Point Nuclear Power Plant, remained offline for several days.
After recovery from this event was complete, the issue of widespread motor reacceleration was not further pursued. Enhanced models were not developed, despite the observations of subject matter experts. This lack of prioritization for creating system models based on available facts after an event is a serious oversight for electric utilities.
After Improving Models, Implement Staged Fault Testing
Staged fault testing is a preventative measure that electric utilities could implement at a relatively low cost. By intentionally creating short circuits of electrical facilities for testing purposes, errors in grid response that could lead to wide area blackouts can be detected and corrected.
This is so easy, yet so difficult. To perform a staged fault test, an electric utility would place a three phase fault on a distribution line near a neighborhood substation in July, and record power system parameters before, during, and after the fault. The fault will be initiated using a trip-free circuit breaker, meaning the circuit breaker will trip immediately upon closing. The short circuit will persist for less than 200 milliseconds.
The difficulty is that an innovation assassin will explain how dangerous it is to short circuit a distribution line. Of course, there is inherent risk in any testing activity; however, Prescient’s proposed staged fault testing methods prioritize safety and minimize risk.
Prioritize and Prepare
In the case of Hurricane Idalia, electric utilities were prepared to handle much larger power outages than occurred. This same level of preparedness should be applied to the inevitable risk of wide area blackouts caused by rare power system events.
Check out our blog to learn more about Prescient’s recommended staged fault testing methods. Or contact us to schedule a consultation with Prescient staff on improving your power system models or implementing a staged fault testing at your electric utility.
This article was written in collaboration with Prescient's Lead Editor Alyssa Sleva-Horine.