Tight conditions cause energy emergency for Texas grid

The article notes that the Electric Reliability Council of Texas Inc. entered Energy Emergency Alert status from 7:30 p.m. to 9 p.m. on Sept. 6 and asked Texans to curtail power demand from 5 p.m. to 9 p.m. on Sept. 7 amid a persistent heat wave. Power markets responded with triple- and quadruple-digit pricing.

Around 11 a.m. Sept. 7, ERCOT issued a news release asking for conservation “due to continued high temperatures, high demand, low wind and declining solar power generation in the afternoon,” which prompted expectations for low operating reserves in the afternoon and evening.

The National Weather Service has issued excessive heat warnings or advisories for most of the more populous eastern half of Texas, and CustomWeather forecasts high temperatures above 100 degrees F through much of that region's major metro areas through Sept. 9. ERCOT set September peak load records Sept. 4–6 and is forecast to do so again Sept. 7–8.

Light wind output

Wind output has been lagging in September. During the typical peak demand hour ending at 5 p.m. CT on Sept. 1–3 and Sept. 5–6, ERCOT has been producing at a level of about 4.6 GW, less than half the 10.4 GW that ERCOT modeled the wind fleet to be producing during the seasonal peak in the summer of 2023. On Sept. 4, the wind fleet produced at a level of 15.4 GW. ERCOT's 1 p.m. CT forecast showed wind production at a level of 6.4 GW on Sept. 7 and 7.1 GW on Sept. 8.

Juan said: “Given high temperatures, very low wind conditions and increasing outages for the thermal fleet given high utilization this summer, the ERCOT system is projected to be very tight on Sept. 7 and Sept. 8, increasing the likelihood of another Energy Emergency Alert event.” 

He adds: “However, whether an EEA event actually occurs is dependent on real-time conditions and unplanned outages that are difficult to predict. Projections for cooler weather and higher wind output in the coming weeks suggest that ERCOT could be in a better state after Friday, barring unseasonably hot weather returning.”

Thermal generation has also encountered problems in recent weeks. On Sept. 4, the latest date for which ERCOT has released information on unplanned outages, ERCOT reported 10.4 GW of thermal generation offline for issues such as forced outage or forced extension of a previous outage. Of that total, 5.9 GW was fired by natural gas and 4.5 GW was fired by coal.

ERCOT delays the release of unplanned outage data in order to minimize opportunities for anticompetitive behavior.

ERCOT's 2023 summer Seasonal Assessment of Resource Adequacy modeled less than 5 GW of thermal generation to be on unplanned outage under typical conditions, with a high unplanned outage scenario surging to 8.4 GW. Only the “extreme unplanned outage” scenario would have a higher total, 11.1 GW, for thermal generation in an unplanned outage.