Controlled power outages will likely last throughout Monday evening and into Tuesday as below-freezing temperatures continue and the state's grid operator and transmission companies work to restore the electric system to normal operations, officials with the Electric Reliability Council of Texas said Monday afternoon.
More than 22,000 New Braunfels Utilities customers experienced rotating power outages, with some seeing repeated rotating outages, since early Monday when ERCOT declared a third-level energy emergency alert and instructed NBU and transmission companies throughout the state to begin rotating power outages as there was not enough power available to keep up with consumer demand.
While the grid operator was already contending with frozen wind turbines and limited gas supplies to generating units on Sunday, a significant number of additional generating units tripped offline when the weather worsened overnight.
That resulted in about 34,000 megawatts of power generation forced off the system.
Rotating outages are controlled, temporary interruptions of electrical service implemented by utilities when the ERCOT must reduce demand on the system.
This type of demand reduction is only used as a last resort to preserve the electric system's reliability as a whole.
NBU officials said Monday afternoon that the utility would continue to shed load as directed.
The amount of load the utility is mandated to shed fluctuates, and NBU officials said they are telling customers they should “prepare for the worst."
NBU officials said rotating outages affect the entire NBU service territory and could last for approximately 45 to 60 minutes at a time before being rotated to another location.
"ERCOT and Texas electric companies have been able to restore service to hundreds of thousands of households today, but we know there are many people who are still waiting," ERCOT President and CEO Bill Magness said in a statement. "It's also important to remember that severe weather, mainly frigid temperatures, is expected to continue, so we're not out of the woods."
ERCOT is instructing transmission companies to shed approximately 14,000 megawatts of load, down from 16,500 megawatts earlier Monday.
"We determine how much reduction in demand is needed to maintain that supply and demand balance," said Dan Woodfin, senior director of system operations at ERCOT, in a conference call Monday. "We tell the transmission owners around the state how much reduction we need, and then they determine where and how to implement those reductions on their system."
NBU is also dealing with system outages outside of the rotating blackouts mandated by ERCOT that affect a small percentage of customers.
Customers who experience a prolonged outage should call 830-629-4628 to report the outage.
One additional factor affecting the restoration of power after a rotating outage, according to NBU, is the in-rush electrical demand that occurs when power is restored. The power coming back on —because heaters are on — can damage the system's fuses and transformers, which can also cause an outage.
In electrical outages, NBU recommends turning the heating unit off or turning the temperature down to reduce the immediate draw of power by electrical devices upon restoration of power.
ERCOT set a new winter peak demand record Sunday, reaching 69,150 megawatts between 6 and 7 p.m., more than 3,200 megawatts higher than the previous winter peak set in January 2018.
ERCOT has initiated system-wide rotating outages only three other times in its history - Dec. 22, 1989, April 17, 2006 and Feb. 2, 2011.
"The lowest temperatures Texas has seen in decades necessitate a shared response across the state, from households to factories," said Public Utility Commission of Texas Chairman DeAnn Walker. "Along with the tools ERCOT uses to maintain the reliability of the grid, common sense conservation also plays a critical role in our state's endurance of this challenge."
Consumers are urged to continue to reduce their electric consumption as much as possible. Steps to help reduce electricity usage include:
Setting thermostats to 68 degrees while at home, or as low as comfortably tolerable.
Setting ceiling fans to the winter setting by running them clockwise to pull the warm air down.
Avoiding using large appliances, such as ovens, washing machines, dryers and dishwashers).
Ensuring doors and windows are sealed properly. Any light through the door indicates a penetration of cold air coming into the home.
Turning off lights, computers, and other electronic devices whenever possible.
NBU is also asking customers to turn on their faucets periodically to keep water lines from freezing.
For more conservation tips, go to https://www.nbutexas.com/energy-action-days.
Also, treat all downed wires as live and dangerous. Report downed wires to 830-629-4628. People should stay at least 10 feet away and never drive over a downed wire.
Gov. Greg Abbott on Monday said he and the Texas Military Department had deployed National Guard troops across the state to help take people to one of the 135 local warming centers set up across Texas.
Other state agencies are also deploying resources and personnel to help local officials clear roadways and assist essential workers, including health care professionals and power grid workers.
Among the resource deployments Abbott announced:
3,300 troopers and 3,300 patrol vehicles from the Texas Department of Public Safety
90 personnel members and 28 high-mobility vehicles from the Texas Military Department
585 personnel members, 531 4x4 vehicles, one aircraft and nine K9 teams from Texas Parks and Wildlife
2,314 personnel, 695 snowplows and 757 4x4 vehicles from the Texas Department of Transportation.
Customers can view ERCOT's daily peak demand forecast, current load and available generation online at ercot.com or download the ERCOT mobile app (available for download at the Apple App Store and Google Play). For the latest grid conditions updates, please follow ERCOT on Twitter (@ERCOT_ISO).
NBU encourages customers to text "NBU" to #85700 to enroll in the Texting Outage Notification System to receive automated text notifications regarding outages, or call 830-629-8400 during business hours from 8 a.m. to 5 p.m. to enroll.
Customers can view an online NBU outage map at outages.nbutexas.com.
ERCOT manages the flow of electric power to more than 26 million Texas customers, representing about 90 percent of the state's electric load.
The Texas Tribune contributed to this story.