A Gustav Story: Dramatic Midnight Mission Reconnects New Orleans-area 'Island' to the Grid
09/04/2008

Three, two, one ... those who heard the countdown in person or by phone said you could have cut the tension with a knife: an engineer called out the sequence to the closing of an electrical breaker by an operator, toward an uncertain result. At stake: whether every remaining light in New Orleans would go out.

The breaker closed. Applause erupted, as a previously "islanded" portion of Entergy's transmission system south of Lake Pontchartrain was successfully reconnected to the rest of the company's system. The innovative operation, later described as "a historic, defining moment" by Entergy Chairman and Chief Executive Officer Wayne Leonard, was completed by a cross-functional team from transmission, fossil, system planning and operations, and nuclear, after Hurricane Gustav heavily damaged key transmission lines in the New Orleans area.

The islanded portion of the system was resynchronized to the grid just before midnight Sept. 2, the day after Gustav slammed into the Louisiana coast at Cocodrie, separating the Amite-South transmission grid and three fossil units from the rest of the system, and causing 850,000 outages, the second most in Entergy's history. A second tie was made minutes later, further stabilizing the grid.

The ties restored the integrity of the southeastern Louisiana transmission system and made it possible for workers to carefully begin restoring load and additional generation for the area. That process continues today.

"This restoration event was critical to the overall restoration effort and is unprecedented on the Entergy system," said George Bartlett, director, transmission operations. "It made it possible to immediately restore high-priority loads such as hospitals, pumping stations, courthouses, television stations and other key infrastructure."

Earlier, unacceptable test results forced the project team to abandon its first attempt to reconnect the area, from the Michoud site in eastern New Orleans. As bad weather continued to plague the region, the team on the ground moved their equipment a few miles to the Almonaster site. There, they hoped to take advantage of new, gas breakers for synchronizing purposes.

Once set up at Almonastor, an engineer called out readings on the synchroscope while a Michoud operator prepared to close the breaker at "12 o’clock high" on the synchroscope, a device that displays on a clock-style face whether power networks and generators can be safely connected. At the same time, connected by telephone conference call, a Waterford 1 & 2 operator was picking up and dropping load on Unit No. 1 at the engineer’s command, in an effort to get the synchroscope turning slowly in the clockwise direction. While Waterford Unit 1, one of three islanded generation units, was adjusted in this way, the other two, Ninemile Unit 5 and Little Gyspy Unit 2, were held steady and in manual operation.

"In Jackson, and at other sites, team members gathered around the phone to hear the countdown to closing the breaker. I think everyone held their breath as the engineer called out '3 o’clock, 6 o’clock, 9 o’clock, and gave a final brief count, and then the systems were back on line," Bartlett said.