The Electric Reliability Council of Texas, the grid operator, reached step two of its emergency procedures almost two hours before 4 p.m., the hour of peak energy use, and cut power to some industrial customers that have agreed in advance to lose power in emergencies.
Thursday was the fourth day in a row that ERCOT has urged residents and businesses across Texas to conserve the amount of electricity they are using from 3 p.m. to 7 p.m. — but the first that the operator has had to undertake step two. Kent Saathoff, vice president of system operations for ERCOT, said on Wednesday that the system cannot take much more than 68,000 megawatts of energy. The peak demand on Thursday is yet to be announced, but more power plants went down on Thursday than in prior days, causing the grid’s problems to intensify. About 4,000 to 5,000 megawatts became unavailable on Thursday, about 1,000 megawatts more than in previous days, according to ERCOT spokeswoman Dottie Roark.
The reason less power was unavailable Thursday, Roark said, is prolonged strain on the generation units. The past three months saw record-breaking demand on the system as a result of the hot weather. “When the generation units have to run for an extended period of time, they trip offline or have to go offline,” Roark said, adding: “It’s like if your car’s overheating.”
By 5 p.m., real-time wholesale electricity prices — which are a good indicator of how worried to get about possible blackouts — had fallen considerably, suggesting that the situation was coming under control. Prices had reached the cap that Texas regulators allow, $3,000 per megawatt-hour, and stayed there for about three hours this afternoon, which is highly unusual (prices in the early morning hover around $30 per megawatt-hour, by contrast). Consumer bills will not see an immediate hit, but could down the road. Tomorrow seems likely to be another hot day that will stress the grid again.
If ERCOT called for rolling blackouts, it would be the first time that’s happened during the summer, Roark said. There have only been three times in 21 years that rotating outages happened, twice in winter (including once in February of this year, during a cold spell) and once in April of 2006, during a time of unusually high temperatures.
In the event that blackouts do happen, residents and businesses across Texas won’t have warning and will be in darkness for as little as 15 minutes and as much as 45 minutes, Saathoff said Wednesday.
The news of possible rotating blackouts arrived on the same day that the state climatologist announced that Texas is officially suffering from the worst one-year drought since records began in 1895 — and that July was the warmest-ever month.