The Texas grid was, again, stretched to emergency levels on Thursday, not seen since Winter Storm Uri in 2021. The high, heat-fueled demand and unexpected fossil fuel power plant failures forced the state’s grid operator to ask residents to voluntarily reduce electricity use to keep the state’s grid online for the 11th time this summer. Hot September evenings are especially hard on electrical grids. Houston, the state’s biggest city, topped out at an official-record-breaking 102°F (with temperatures up to 109°F recorded at Hobby Airport) and roasting in 90°F+ temperatures well into the evening.

The extreme heat caused peak demand 82,705 MW, smashing ERCOT’s previous September record of 72,370 MW. More than 6,000 megawatts of coal- and gas-fired electricity generation was offline late Thursday morning — more than ERCOT, the state’s grid operator expected — and demand was projected to exceed supply by 200 MW Thursday evening. (Houston Chronicle, Utility Dive AP; Heat record: Reuters; Hobby Airport: Fox26; Summer heat: Texas Tribune; Wednesday: E&E $; Climate Signals background: Extreme heat and heatwaves)