RALEIGH. N.C. (WNCN) — Duke Energy put rolling blackouts in place just before Christmas, saying energy demand exceeded supply. 

N.C. State University Assistant Professor Dr. Jordan Kern says rolling blackouts can help protect the power grid. 

Most of us flip on a light switch or turn on the heat without giving any thought to the power grid, but experts say keeping the power on requires a complex operation and delicate balance.

“If you overproduce or underproduce relative to demand, it can disrupt that and actually significantly negatively impact the physical integrity of the grid … kind of wipe the whole thing out,” noted Kern. 

He says utility companies can use rolling blackouts to force a reduction in demand and protect the entire system.

“When they institute rolling blackouts, it is an effort to make sure the grid isn’t broken beyond repair,” Kern said, adding that it also spreads the impact among multiple communities. “It’s a way to share that responsibility, as well. One community will be without power for a little while, then another, then another.”

Duke Energy saw higher demand than expected with the extreme cold just before Christmas, but Kern, who studies the impact of climate change on the power grid, says during the coming years, he expects demand to become even greater as summers get hotter

“That traditionally has been the period of our highest electricity use, and I think heat waves also stress the grid in other ways that can interrupt service, not just by increasing demand but by causing failures at types of power plants,” he said. 

Along with warmer summers, Kern says we could continue to see periods of extreme cold, caused by the weather phenomenon known as a polar vortex. 

“What we might have is hotter summers and warmer winters overall, punctuated by these weird severe cold events which, understandably, makes it hard to plan for if you’re a company like Duke Energy.”

He says individuals can make a difference. Many of us recently received texts from Duke Energy asking us to conserve power to help avoid rotating outages.

“Collective efforts to reduce electricity demand by a little bit does add up,” said Kern.  “And it can prevent those rolling blackouts.”