The manager of the state's electric grid is asking for Texans to conserve electricity until 9 p.m. Friday.
The Electric Reliability Council of Texas, or ERCOT, said high demand and low wind-power generation are expected to result in tight supply reserves. An imbalance in energy supply and demand can damage the grid and lead to blackouts.
"Current forecasts are showing a potential to enter emergency operations this evening," ERCOT said.
This is the fourth conservation request the grid operator has made this month, as energy use has spiked because of the summer heat.
These requests don't mean a blackout is around the corner. ERCOT issues them to avoid going into the first of three energy emergency alert levels, required under federal regulation.
Each of these alert levels gives the grid operator other — sometimes costly — options to balance the grid.
At Energy Alert Level 1, for example, ERCOT may pull added energy from some of the few ties it maintains with neighboring grids. At Alert Level 2, ERCOT pays large industrial or commercial consumers to reduce their power consumption to balance supply and demand on the grid.
"Those are tools you don't want to use very often, but they are tools that you use in case of emergency," Joshua Rhodes, an energy researcher at UT Austin, said.
If energy supply remains insufficient after these options are exhausted, blackouts become a possibility. Though, Rhodes points out, rolling blackouts in the summer are very different from the statewide power failure Texas experienced in the winter of 2021.
For one thing, the power crunch would likely subside once night set in over Texas, and people stopped blasting their AC.
"I would imagine if we did have any rolling blackouts they would actually roll," Rhodes said. "It would be 30 minutes, maybe an hour, depending on where you are."
Some have questioned the effectiveness of these repeated voluntary conservation requests, arguing that ERCOT should pay residential consumers to reduce their power as it does big industrial users.
But the grid operator said the requests are working. ERCOT said it did not have to declare an emergency alert Thursday because Texans reduced consumption by turning off large appliances and turning down their ACs. It also noted more wind power, rain in the Houston area and other factors.
ERCOT said it expected low wind-power generation and high demand to persist through the weekend because of the extreme heat.
