Duke Energy adding up repair costs for Florence, Michael - Charlotte Business Journal

Duke Energy Corp. says it handed ended up with more than 10,000 line crews and support workers in the Carolinas to restore power to about 1.1 million customers who suffered outages caused by Tropical Storm Michael.

The storm raced through the two states Thursday, causing considerably more damage than the company had expected last week, when it assigned 6,000 workers to the Carolinas. Duke's initial estimates for outages ranged from 300,000 to 500,000 customers.

Duke (NYSE: DUK) spokeswoman Meghan Miles says the company has not yet compiled the estimated costs it can report for repairing damage from Michael and Hurricane Florence, which swept through the states in September.

Matthew repairs

When Hurricane Matthew struck the Carolinas in October 2016, Duke released its first estimate of the repair costs - pegged at $200 million - with its third-quarter earnings report in November of that year. Miles says Duke cannot comment on whether the figures for the most recent storms will be available when Duke reports its third-quarter earnings this year on Nov. 2.

Duke has restored power to more than 1 million Carolinas customers who lost power due to Michael. By 2 p.m. Monday, Duke says, fewer than 27,000 customers remained without power. No significant outages remained in Mecklenburg County.

The hardest-hist county remains Guilford, home of Greensboro and High Point, which still had more than 10,000 Duke customers without power. Second was Rockingham County, just north of Guilford, with 6,865 customers without power.

Florence, though a less-potent hurricane, moved more slowly through the Carolinas and caused more than 1.8 million customers to lose power.

Sutton plant

That storm also put a large Duke Energy Progress natural gas plant out of commission. The Cape Fear River flooded its Sutton Plant near Wilmington on Sept 20, close to a week after the storm made landfall at nearby Wrightsville Beach as a Category 1 hurricane.

The slow-moving storm dropped more than 30 inches of rain on the area, and the river breached the dam to Sutton Lake and caused significant flooding in the 625-megawatt combined-cycle natural gas operation that replaced the coal units at Sutton in 2013.

As of Monday, one 50-megawatt turbine unit at the site used for peak power was back on line. A second 50-megawatt peaker is expected to come on line in the next day or two, says Duke spokesman Rick Rhodes.

But Duke does not have a time frame for when the combined-cycle unit will come back on line. That unit is made of two 170-megawatt gas turbines and a 275-megawatt steam turbine. The gas turbines may return to service by the end of the week, Rhodes says. But it is not clear when the steam unit can return.

Duke does not use simple gas turbines as base-load plants, which is how it uses its combined-cycle plants. All the gas turbine units are likely to be used only as peak-load plants until the steam unit comes back on line, Rhodes says.