Safely Restoring Power After a Massive Desert Monsoon
By Casey Wian
Published on September 16, 2021
Shortly after midnight on Aug. 13, an unusually strong monsoon knocked down five Southern California Edison transmission towers- Opens in new window over a remote, two-mile stretch of the western Arizona desert.
“There were some high winds, heavy rains and lightning in the area,” said Peter Guereca, SCE senior grid manager. “The last time we had multiple towers down in an event like this was probably close to 20 years ago.”
Normally, the Colorado River/Palo Verde line transmits from eight to 15% of SCE customers’ daily power consumption.
“Because of the demand, we need to get the line back up as soon as possible,” Guereca said, as he surveyed a team of more than 70 SCE employees and contractors who rushed to the Arizona desert to begin repairs. Permanently replacing the downed towers can take months, in part because they must be seated in concrete foundations that need time to cure. Because customers can’t wait that long- Opens in new window, the utility has a much faster solution.
“We actually keep a stash of emergency structures for situations like this. We keep them centrally located within our territory so we can react to an emergency in a timely fashion,” said Michael Baker, SCE general superintendent, Eastern Transmission.
An SCE team quickly mobilizes to begin installing temporary, rapid-response structures known as Lindsey towers- Opens in new window.
“The Lindsey system is a modular system that makes it faster and easier to restore the lines without having to install foundations,” said Viet Nguyen, senior engineer for SCE’s Transmission Engineering Group. “Foundations take about seven to 28 days to cure and set, so with Lindseys, there is no foundation. Everything is supported by guy wires, so we can erect these in days and get the lines back up and energized much faster.”
Crew members gather materials for the Lindsey structures in a staging area, then move components by truck to locations near the downed towers. They are then assembled and raised with large cranes in a process resembling a giant erector set.
It may sound simple, but in the Arizona desert more than 50 miles from the nearest town, with temperatures soaring into triple digits, potential hazards are everywhere. Dehydration, rattlesnakes, scorpions, twisted metal and ultra-sharp porcelain glass from the downed towers are just some of the dangers that SCE Field Safety Advisor Richard Sapp must help crew members avoid.
A veteran of nearly four decades in the electric power industry, Sapp begins each workday with an all-hands safety briefing- Opens in new window.
“We want to make sure everybody goes home safe the same way they came in,” Sapp said, choking with emotion. “I don’t know why I’m getting emotional, but I’ve been out here on these jobs and there is a lot of moving parts.”
Another challenge is protecting the environment. That responsibility falls to biologist Aurelia Gonzalez, an SCE contractor who combs the area looking for habitat of the Sonora Desert Tortoise, Big Horn Sheep and other creatures.
“For them to conduct the work they need to do, they might have to drive over the desert. In areas where there are not roads already built, I sweep those areas for endangered species. I’m out there making sure that the disruption of soil is not going to harm any species,” Gonzalez said.
Less than a week after the transmission towers fell, the first Lindsey tower goes up. Five more are erected in the next few days, and a critical component of SCE’s power grid is again functioning.
For Michael Baker and team, there’s no victory lap, just the satisfaction of a job done safely (with no injuries), efficiently and with minimal environmental impact.
“Success is definitely just having the lines built back up and reenergized, getting an important source of power back into our Edison territory,” he said.
Replacement of the permanent transmission towers is expected to be complete in late 2021 or early 2022.