Representatives from AEP Ohio and PJM Interconnection appeared before the Public Utilities Commission of Ohio last week to discuss the power outages that impacted Columbus the week of June 13. Both entities established that outages were a result of infrastructure damage caused by heavy storms across the state, and heightened demand for electricity in the 90-degree days that followed.
Damage to electricity infrastructure during the storm on June 13 – including power lines and transmission systems throughout Ohio – directly caused 21,257 AEP customers in Columbus to lose power, AEP Ohio President Marc Reitter said. But thousands more customers lost power over the coming days, which AEP representatives say was done intentionally to prevent further damage to the electrical grid.
With some parts of the electricity system unable to deliver power following the storm, functioning infrastructure was strained by higher-than-usual demand. For the electric grid to successfully deliver power to all customers, the supply of and demand for electricity must remain approximately equal over time.
Throughout the afternoon and evening of June 13, PJM saw several AEP transmission lines “trip,” or go out of service, in Columbus.
“When one of these lines goes down, other lines in the system have to carry that electricity,” Michael Bryson, Senior Vice President Operations at PJM, said. “If enough lines go down, the surrounding lines begin to reach or exceed their operating limit.”
As operating transmission lines in Columbus became more overloaded, PJM issued load shed directives to AEP Ohio. When PJM issues a load shed directive, AEP Ohio has five minutes to act, cutting customers' power to restore a balanced electricity supply and demand, Bryson said.
Over the next few days, through June 15, PJM continued to issue load dump directives, causing more than 150,000 Columbus residents to lose power in emergency forced outages, according to AEP Ohio. The outages reduced the load by more than 550 megawatts.
Commissioner M. Beth Trombold asked Bryson how PJM determines who loses power when the load is reduced. Bryson said that the utilities, like AEP Ohio, are given the directive to shed enough megawatts to reach the load rating PJM has set.
“We’re really relying on their ability to figure out what customers are going to be affected as quickly as possible because they have that expertise,” Bryson said.
Several PUCO Commissioners inquired about what might have happened if the load shed directives were not followed. Bryson explained that cascading outages can occur, causing even more customers on the grid to lose power, over a much larger geographic area.
Another concern raised throughout the review related to AEP Ohio's ability to notify affected customers in a timely fashion. Because of the unplanned nature of the June 13 to 15 power outages, most Columbus residents did not know of them prior to their occurrence. Impacted AEP customers lost food, faced challenges using medical devices, and had no time to prepare for the heat.
Though there was no pre-outage communication, AEP Ohio claimed to have kept customers informed during and after the outages.
The AEP Ohio representatives acknowledged the challenges experienced by customers as a result of the mid-June emergency forced outages. Toward the end of the meeting, Toby Thomas, senior vice president of energy delivery, reaffirmed the company’s commitment to customers and improvement.
“In retrospect, is there anything AEP thinks it could have done differently to avoid or to mitigate the sustained outage in the neighborhoods that suffered that outage?,” Commissioner Lawrence Friedeman asked.
“Commissioner, not that I’m aware of,” Thomas said.
The Public Utility Commission of Ohio will continue to investigate the outages and encourages impacted customers to share their stories with the PUCO Call Center at (800) 686-7826. Watch the full meeting below.