Duke Energy explains why it ruined North Carolina’s Christmas Eve

But company leaders maintained that they “made the only decision” they could in implementing rolling blackouts and said they will do all they can to prevent something similar from happening again.

The latest: Duke Energy executives went before the N.C. Utilities Commission to explain what led to the longer-than-anticipated blackouts over the holidays: strong winds and a historic temperature drop, poor forecasting of customer demand, and equipment malfunctions.

• “We will learn from this event. We will strive to lower the probability that this type of event happens again,” said Sam Holeman, Duke’s VP of system planning and operations. “But if we have similar conditions and similar operating environments in the future, operators will take the same actions.”

Why it matters: The sudden blackouts left North Carolinians in the cold as temperatures dropped below freezing, sparking concerns about the reliability of the state’s power system with extreme weather events on the rise.

What happened: Duke explained it uses a model that forecasts demand based on historic usage and past weather. On Dec. 23, the company thought it had sufficient resources for Christmas Eve. But that night, demand started rising faster than predicted.

• Three plants — Roxboro Plant in Semora, Dan River Steam Station in Rockingham County and Mayo Plant in Roxboro — were operating at less than their power capacity because of freezings. Duke attempted to purchase power from other utilities as it does during warmer months, but they were also impacted by the winter storm.

“We were confronted with the hard truth that our energy demand would soon be eclipsed by our capacity,” said Kendal Bowman, president of Duke’s North Carolina operations. “At that time, we made the only decision that we could. For the first time in our company’s history, we began rolling service disruptions.”

Between the lines: Duke Energy acknowledged its communication was not entirely accurate or steady throughout the day.

• Initially, messages said blackouts would last 15 minutes, which was true for some customers. In other cases, an automated tool failed and Duke had to manually restore power. By early afternoon, the company notified customers that power would return by the end of the day.

What’s next: Duke Energy said it is internally reviewing its systems and procedures and is looking at how other providers managed during the winter storm.

• “We don’t ever plan to be in this situation again,” said Scott Batson, senior vice president and chief distribution officer at Duke.

What they’re saying: “We own what happened,” said Julie Janson, CEO of Duke Energy Carolinas. “We have set out on a path to ensure that if we’re faced with similar challenges, we will see a different outcome and provide a better customer experience.”