AUSTIN, Texas — ERCOT CEO Pablo Vegas thanked Texas consumers Thursday for helping the grid operator survive tight operating conditions this summer, saying their response to conservation appeals has been “nothing short of tremendous.”
“Over the last 10, 11 days, we’ve asked Texans quite a bit to conserve energy during broad periods of the afternoon and early evenings,” Vegas told ERCOT’s Board of Directors Thursday. “We’ve seen each of the days that we have made those calls a material and meaningful impact on energy demand that has contributed … to get through a tight period of operations without having to go into emergency operations.”
The grid operator has made nine appeals for voluntary conservation this summer, including six times in seven days since Aug. 24. Residential customers are not compensated for their reduction, unlike businesses that participate in demand response programs.
The oppressive heat that has baked Texas since June has lessened this week, and demand with it. After recording more than 200 hourly average demand marks of 80 GW this summer, the average peaks have reached only 78.12 GW since Sunday.
However, ERCOT still has encountered tight conditions during the early evening, when solar power ramps down and wind resources, which generally contribute less than solar during the summer, try to fill the gap.
The problem this week is with thermal generation units, which have been running full bore this summer. On Wednesday during ERCOT’s latest conservation appeal, thermal outages neared 12 GW, almost a third above what the ISO terms an “extreme” level.
“We had more thermal outages coming off of a long stretch of very high demand and high utilization,” Vegas said. “It’s not surprising to see some mechanical breakages happening on some of the dispatchable generation.”
He told the board that ERCOT’s new normal is managing three primary variables that drive the grid’s reliability on any given day: demand on the system, the “traditional” thermal dispatchable fleet’s availability, and intermittent renewable generation’s performance.
“The combination of those three contributes meaningfully to whether or not we’re going to have enough supply to meet demand,” Vegas said. “When you have a challenge with one or even two of those, sometimes things can be tight and we get through it. And if you have issues with all three of them, you can have very tough conditions.”
Vegas said that on Aug. 17, operating reserves dwindled to about 600 MW during the evening ramp down. ERCOT resorted to deploying its ancillary services to find extra supplies to meet demand. That included its emergency reserve service, under which participants are paid to take their loads offline.
“What we’ve been experiencing throughout the summer has been some combinations of those three at different points in time,” he said. “That’s why it’s so critical that we have these tools available to us to manage these very quickly evolving situations and circumstances.”
ERCOT has set 10 new all-time peaks as of Aug. 23. The current mark of 85.44 GW, set Aug. 10, still stands. That is a 6.7% increase over last year’s peak, a stunning load growth when compared to the industry’s normal 1% gain year over year, Vegas said.
“The Texas economy continues to be booming and this is a great outcome for the state of Texas. It’s bringing opportunity, it’s bringing jobs … but it’s also bringing demand,” he said. “I don’t think anybody expects the growth to slow down meaningfully, so we need to be positioned to lean into that and to support that growth as we move forward.”
