Texas faces 16% chance of grid emergency during evenings in August, ERCOT says

The period from 8 p.m. to 10 p.m. will be the riskiest for the Texas grid.

Texans’ risk of dealing with emergency grid conditions after sundown will top 16% in August, according to a new report from the Electric Reliability Council of Texas. And the risk of rolling blackouts during the hour beginning at 8 p.m. is 12%, the state grid operator said Friday.

The elevated risks come after sundown when the grid loses its cushion of supply from solar power and complicated by a chokepoint in transmission lines near San Antonio and concerns about reserve supply.

ERCOT’s report comes after a federally appointed grid watchdog’s modeling last month showed Texas facing a slightly higher risk this summer. The North American Electric Reliability Corp. summer assessment forecasts an 18% risk of emergency conditions and 14.6% risk of rolling blackouts and controlled outages.

“The more concerning scenario is when you have very low wind performance in the northern part of the state and you’ve got a lot of supply or wind in the southern part of the state,” ERCOT CEO Pablo Vegas said in a May interview.“And you’ve got very high demand across the whole state. That kind of combination creates the limitation of trying to get power outside of some part of the state.”

He was referring to the San Antonio chokepoint where transmission lines may get overloaded and cause cascading outages, a condition putting the entire Texas grid at risk. Overloading the circuit was blamed for ERCOT entering emergency conditions in September, a situation that brought the state closer to rolling blackouts than it had been since a deadly winter storm in February 2021.

ERCOT said its modeling accounts for potential wind power imbalances that could overload the South Texas transmission lines.

Adequate power reserves are also a concern for August.