As Winter Storm Elliott hammered the southeastern United States around Christmas time last year with snow, ice and sub-zero wind chills, local utilities and the Tennessee Valley Authority were forced to enact rolling blackouts to save power.

TVA Spokesperson Adam May said since then, TVA has invested nearly $123 million to enhance system reliability at its coal, hydroelectric and gas facilities.

May said of the 232 power generating units TVA operates, 38 were “negatively impacted” due to the extreme cold, mostly due to instrumentation freezing. On Dec. 23, 2022, TVA reported its highest ever 24-hour electricity demand.

“For the first time in TVA 90-year history, we implemented load curtailment on Dec. 23 and Dec 24,” May said in the email. “Each of the 153 local power companies have a plan to curtail load while minimizing the effect on their customers.”

Mark Iverson, general manager for BGMU, said in a Jan. 3 report to the Bowling Green City Commission that TVA requested rolling blackouts from local utilities to ease the demand.

“Managed rolling curtailment is a much better condition to find yourself in than the alternative, which is a collapsed electric grid,” Iverson said.

Chad Spencer, electrical systems manager for BGMU, said TVA asked BGMU to interrupt 5% of its load during the storm, and later 10%. “Load” is known as customers’ need for electricity.

The rolling blackouts were for various durations and occurred across much of the southern U.S.

Spencer said BGMU performs regular maintenance on all of its critical equipment, especially when extreme weather conditions are in the forecast. Additionally, Spencer said a system is in place to monitor critical components and move load around to relieve stress.

However, a risk of power failure is always present.

“You could have equipment failure at 75 degrees,” Spencer said. “There’s always a chance for equipment failure, but extreme temperatures do increase the odds of equipment failure.”

The TVA also said it will invest $120 million throughout fiscal year 2024 to specifically improve the reliability of its fleet of generation facilities.

“TVA is in the process of installing state-of-the-art smart heat trace monitoring systems which send real-time readings to our control rooms, allowing operators to be more responsive to indications of potential freezing issues,” May said in the email.

May also said “heated electrical cabling” has been installed around piping, preventing freezing of both the liquid in the pipes along with the instruments used to monitor the system.

Additionally, TVA conducted almost 3,400 “winter weather activities” across its Power Operations fleet. This included adding or upgrading insulation and enclosing vulnerable equipment.

Mike Kochasic, a meteorologist with the National Weather Service in Louisville, said the likelihood of southcentral Kentucky experiencing another winter storm on the scale of the one last year is “fairly low.”

Kochasic said this is because 2023 is an El Niño year. El Niño, Kochasic said, is a phenomenon where temperatures in the Pacific Ocean are warmer than average. This leads to warmer and dryer winters in Kentucky.

However, there is a caveat to an El Niño winter.

“It only takes one storm system to come down and give us cold temperatures and snowy weather,” Kochasic said. “That doesn’t mean it’s going to be warm and dry, period.”