Texas Power Emergency Hinged on Stranded Wind-Farm Supplies

(Bloomberg) -- Texas’ worst power crisis in more than two years was triggered when officials were forced to halt deliveries on a long-distance transmission system, stranding electricity supplies hundreds of miles from major population centers.

As record heat spurred demand for power to run air conditioners across Texas on Wednesday, a key transmission line supplying the Dallas area showed signs of an imminent overload. That prompted the Electric Reliability Council of Texas to issue a so-called transmission watch alert at 6:34 pm local time, suspending some power shipments, likely from wind farms, in South Texas.

The precautionary measure intended to preserve the integrity of the transmission network forced generators to curtail about 1,000 megawatts just as electricity supplies were being stretched by unprecedented consumer demand, said Brad Jones, Ercot’s former interim chief executive officer. That’s enough power to supply roughly 200,000 homes.

“The grid was facing the potential of congestion overload on the line coming from south Texas toward Dallas,” Jones said during an interview. “All the wind that was on in the south was struggling to get to Dallas to help meet demand. So right in the middle of this, Ercot had to reduce generation in the south to prevent that line from being overloaded.”

Within minutes of the transmission alert, Ercot began deploying emergency power reserves while utilities braced for rolling blackouts. Ultimately, forced power outages were averted as demand began to ease after sunset. An Ercot spokesperson declined to comment. Governor Greg Abbott’s office notched the close call as a win.

“During record-setting temperatures this summer, Texas set and broke power demand records 10 times without any system wide issues or disruptions for the more than 26 million Texans served by the ERCOT grid,” Abbott spokesman Andrew Mahaleris said in an email. “The grid has been able to meet those challenges and respond in record ways, providing more power than ever before, in large part because of the reforms passed by the legislature and signed into law by Governor Abbott.”

Power demand is expected to once again bump up against supply limits in the second-largest US state around 8 pm, according to Ercot’s latest forecast.

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