Texas power companies automatically raised the temperature of customers' smart thermostats in the middle of a heat wave

• Texas power companies remotely adjusted customers' smart thermostats, KHOU 11 reported.
• Customers said they had unknowingly agreed to let companies raise the temperature to save energy.
• Texas regulators asked residents last week to conserve energy amid a heat wave.

Texas power companies heated up some customers' homes last week by remotely controlling their smart thermostats, KHOU 11 reported Thursday.

One resident in the state, which is facing a heat wave that is straining its power grid, told KHOU 11 his family had awoken from a nap sweating and shocked their home had gotten as hot as 78 degrees Fahrenheit.

It turns out they had enrolled their thermostats in an energy-conservation promotion called Smart Savers Texas, run by a company called EnergyHub, in partnership with power companies. The program gives EnergyHub permission to adjust participants' smart thermostats remotely during times of peak energy demand, in exchange for entry into a sweepstakes.

"During a demand-response event, Smart Savers Texas increases the temperature on participating thermostats by up to 4 degrees to reduce energy consumption and relieve stress on the grid," Erika Diamond, EnergyHub's vice president of customer solutions, told Insider, adding that "the ability to reduce energy consumption is critical to managing the grid, in Texas and nationwide."

Thermostat owners typically get an offer to participate in the program from their device manufacturer or energy provider via mobile app or email, Diamond said, and "every participant actively agrees to the terms of the program and can opt out of a demand-response event at any time."

Diamond told USA Today that demand-response events occurred rarely, about two to eight times a summer.

EnergyHub did not immediately have a response to Insider's questions about whether it notified participants before adjusting their thermostats.

CenterPoint Energy, a major energy provider in Texas, told KPRC 2 that it had "conducted a test curtailment event from 2 p.m. to 5 p.m." on Wednesday and that at its direction, EnergyHub "adjusted the thermostat set point for those enrolled customers."

Months after winter storms overloaded Texas' power grid, leaving millions without power or clean water, the state is dealing with a heat wave that led the state's top energy regulator, the Electric Reliability Council of Texas, to ask residents to conserve power last week.

Smart thermostats allow power companies one way to reduce strain on a power grid at scale, but they also sparked privacy and safety concerns for some residents who said they weren't aware what they had enrolled in.

"Was my daughter at the point of overheating?" Brandon English, a Deer Park, Texas, resident, told KHOU 11, adding: "She's 3 months old. They dehydrate very quickly."

"I wouldn't want anybody else controlling my things for me," English told KHOU 11, saying he unenrolled his thermostat after the event.