DALLAS — As Texas went into energy conservation mode this week, some residents might have noticed something odd on their wall: their thermostat changing the temperature on its own.
They weren't just seeing things.
TXU Energy confirmed to the Fort Worth Star-Telegram that its "Demand Response Program" can remotely change customers' thermostats "by a few degrees for a short time, normally less than an hour" when the power grid is under stress, like on Wednesday.
It was unclear how many homes had thermostats changed Wednesday, though TXU said tens of thousands of customers participate in the program. TXU did not respond to a request for comment from WFAA on Thursday.
In June, The Verge reported that CenterPoint Energy in Houston also has certain remotely-controlled thermostat programs through EnergyHub.
In Texas, the programs are in the form of EnergyHub's rewards program known as "Smart Savers Texas."
Customers have the choice of opting in to the program by allowing EnergyHub and their energy provider to "remotely access your thermostat to make brief, limited adjustments ... at times of peak electricity demand in the summer," the Smart Savers website said.
When a customer opts in to the program, they are automatically entered into a $5,000 sweepstakes. Customers have to have a so-called smart thermostat, such as Nest, that is connected to the internet.
According to the Smart Savers terms, temperature adjustments would typically happen on weekdays from 1 p.m. to 7 p.m., "but may extend outside of that time window for system testing or rare emergency conditions."
Last summer, some customers in Houston complained when they woke up to warm temperatures and found out their thermostat had been remotely adjusted.
The customers apparently weren't aware they were enrolled in a remotely-controlled program, telling KHOU they unenrolled as soon as they found out.
The Electric Reliability Council of Texas issued a conservation appeal to all Texans on Wednesday, asking homes and businesses to reduce their energy usage from 2-9 p.m.
Scorching hot temperatures have strained the Texas power grid this week; ERCOT also asked Texans to conserve energy on Monday.
On both days, the power grid's energy demand was on the same level as the supply, though no rolling blackouts were reported as a result.