Damaged transmission towers slow Hurricane Laura recovery

Published on September 02, 2020 by Hil Anderson

Credit: Entergy

Hurricane Laura caused “catastrophic” damage to Louisiana’s electric grid, which will leave some customers without power for weeks, Entergy said Wednesday in an update on the state’s recovery from last month’s storm.

“Our damage assessments indicate catastrophic damage to our electrical infrastructure,” the company said in its Sept. 2 update. “We expect the recovery to be as difficult and challenging as we have ever faced in the past. Customers should expect extended power outages lasting for weeks.”

Entergy reported 140,449 customers in four states still without power since the storm made landfall as a category 4 hurricane on Aug. 29, a 77-percent restoration rate from the peak 616,000 customers. In Louisiana, the restoration rate was 56 percent with 119,786 still without power.

Throughout the region, approximately 268,000 customers were still without power, down from a peak of nearly 989,000 and a restoration rate of nearly 73 percent, according to the Edison Electric Institute. More than 29,000 utility workers from across the United States and from Canada were still repairing the damage in the storm area.

“The damage assessments completed by crews on the ground and by helicopter and drone flights have revealed the catastrophic damage that Laura caused to nearly 1,000 transmission structures in Louisiana and parts of southeast Texas,” EEI said in its Sept. 2 update. “Often, crews must use fan boats, barges, and tracked vehicles just to reach some of the most heavily damaged areas.”

Laura took a heavy toll on the largest of the transmission towers that distribute power throughout the state. The major steel structures that support the mainstay 500,000-volt power lines buckled in some locations and will require a significant construction effort to repair.

Particularly hard hit was the Lake Charles area and its many refineries, chemical plants, and power plants. Entergy owns five of the seven transmission corridors supplying Lake Charles. “All seven have been catastrophically damaged,” Entergy said. “While not all assessments have been completed, the damage is some of the most severe the company has experienced.”

The Louisiana Public Utilities Commission told The Advocate newspaper that a shipment of new transmission towers was on its way from Florida.

“The transmission structure that supports a 500,000-volt line weighs roughly 40,000 pounds,” Entergy said. “Transporting just one requires three 18-wheeler trucks. For comparison, one 18-wheeler can transport about 50-100 distribution poles.”

The gas-and-oil sector in the region was also ramping up after riding out Laura. Refineries and chemical plants continued to restart, and offshore drilling platforms were resuming production as well. The federal Bureau of Safety and Environmental Enforcement said Monday that 77 rigs remained evacuated with 24.69 percent of gas production still shut in along with 28.38 percent of oil production.