UPDATE: This article has been updated as of Wednesday, Aug. 21.
The cause of Sunday’s widespread power outages and “brownouts” has now been identified, according to Southwestern Electric Power Company.
A press release distributed by SWEPCO yesterday named the source of the incident as vegetation contacting power lines.
"A power outage that affected 85,000 East Texas customers Sunday was caused by an overload on part of the power grid after vegetation came into contact with two major power lines, according to preliminary investigation by Southwestern Electric Power Co.," the release read.
SWEPCO's investigation found a power line came into contact with vegetation around 4 p.m. Sunday, causing a fault in the power system. Heat and high customer load caused a second high-power voltage line to sag into vegetation, causing a second fault around 4:15 p.m., the report read.
The press release said the investigation is ongoing as SWEPCO works to prevent similar incidents in the future.
“We’re continuing to investigate the sequence of events to better understand what happened,” said Malcolm Smoak, SWEPCO president and chief operating officer. “We are inspecting power lines and clearing additional trees and other vegetation in problem areas along transmission rights-of-way, where excessive rain this spring and summer has resulted in high vegetation growth.”
Power outages began to occur in Kilgore and in several East Texas cities at approximately 4 p.m. Sunday. Many local residents experienced temporary drops and interruptions in their power service for several hours (or longer), resulting in widespread brownouts.
Tens of thousands of residents in two states across SWEPCO’s network were affected, including thousands in Kilgore. SWEPCO reported 85,000 customers were without power at the peak of the incident around 7 p.m. Sunday.
On Tuesday, SWEPCO Corporate Communications spokesperson Michelle Marcotte said 4,896 customers were without power Sunday in the Kilgore area and surrounding communities, including Liberty City and Leverett’s Chapel, but power had been restored to all those customers as of Tuesday.
Texas has been using record levels of electrical power this summer. Last week, the Electric Reliability Council of Texas, which manages the flow of electric power to millions of Texans, issued two emergency alerts because power reserves had dropped to low levels following a sustained state-wide record-setting power load “due to continued high temperatures throughout the ERCOT Region”, according to an ERCOT release.
The Emergency Alert Level One, the least severe emergency level, was cancelled later in the week and the statewide power shortages are not related to the East Texas brownouts, according to ERCOT.
“The two would have been completely unrelated,” said ERCOT Corporate Spokesperson Leslie Sopko Tuesday.
“Emergency alerts at level one, that means our operating reserves are low. When we declare an EEA, we take advantage of additional reserves. We have several other resources that we use before we ever get to rotating outages.”