Dive Brief:

Category 4 Hurricane Michael barreled onto the Florida's panhandle Wednesday, knocking out power to over 800,000 customers across the Gulf shore and into Alabama, Georgia and the Carolinas as the storm continues to move northeast.

The "unprecedented" nature of the storm could mean Gulf Power will have to rebuild its system in the heaviest impact areas, according to a Wednesday afternoon press release from the utility. Duke Energy is also anticipating "destruction of major parts of [its] electric system," due to the strength of the storm, the utility's senior communications consultant Peveeta Persaud told Utility Dive.

Southern Company announced Thursday morning it would be reducing power in two units at its 1,751 MW Farley nuclear plant in Alabama as a "precautionary measure." As the storm moves northeast, Duke says up to half a million customers in the Carolinas could lose power.

Dive Insight:

Two are dead from Hurricane Michael, which is estimated to be the strongest hurricane to hit the U.S. in almost 50 years and predicted to cost around $30 billion in damages and production loss.

As of Thursday morning, the storm had cleared Florida and was downgraded to a tropical storm as it moved up through Georgia into the Carolinas.

Gulf Power was forced to temporarily suspend its workforce from doing repairs because of high winds, which neared 150 miles per hour.

"Crews will restore power until winds reach 30 mph when it becomes unsafe for them to be up in buckets," Gulf Power spokesperson Jeff Rogers said in a press release.

The utility estimated early this week a quarter million customers could be without power because of the storm. As of Thursday morning almost 113,000 customers in Gulf Power's service region were without power.

"In the hardest hit areas, the possibility exists that we will be rebuilding our system while we are restoring power," said Rogers. "Customers in the high impact areas could be without power for weeks."

"We are preparing for multi-day restoration, up to a week," said Duke's Persaud, adding that the high winds have led the utility to "prepare for the worst."

Michael, downgraded to a tropical storm on Thursday, moves into the Carolinas just one month after Hurricane Florence hit the region, triggering coal ash spills and causing the shutdown of a gas plant in North Carolina. There is still a debate between Duke Energy, state officials and waterkeepers about the level of contamination in waterways near the spills.

The last storm to hit Florida was Hurricane Irma, which left millions without power last year. The state issued a report this summer assessing utility hardening efforts and found they were markedly improved compared to the 2004-2005 hurricane season, although customers were largely unsatisfied with response time and power restoration.