ERCOT staff worked to ease anxieties among members of the Texas media Thursday after releasing a pair of resource adequacy reports that show the grid operator has healthy reserve margins this summer and into 2026.
The grid operator said it has sufficient capacity to meet most extreme scenarios this summer with a reserve margin of 15.7%, nearly double the 8.6% margin in 2019. The margin climbs to 35.1% in 2023, with increased demand chipping that away to 32.3% in 2026.
Still, that was a hard sell for media representatives who were told last November that ERCOT had enough generation to meet demand during the winter. The grid operator’s resource adequacy scenarios did not anticipate that the grid would lose half its generating capacity during February’s winter storm and its days of extreme temperatures. Stung by the dayslong blackouts and accompanying loss of life, reporters questioned why ERCOT should be trusted this time around.
“We recognize we failed to clearly communicate what the potential risks were going into the winter,” Warren Lasher, senior director of system planning, said during a media briefing to explain the reports. “We have developed these reports and tried to communicate, based on recent operational outcomes, what the potential outcomes might be.”
Staff added several low-probability, high-impact situations similar to the storm in its seasonal assessments, ERCOT said, “to ensure all market participants and government officials have a comprehensive view into market conditions.” Staff said they believe there is a less than 1% chance that the extreme situations will actually occur, pointing out that the February was about a one-in-100 event.
ERCOT said it expects to have 86.9 GW of total resource capacity, enough to meet an expected peak demand of 77.1 GW this summer. That would be a new demand record, breaking the mark of 74.8 GW set in August 2019.
Lasher again assured his audience that the state’s generators would be up to the task, noting that the system is built to withstand the Texas summer heat. Temperatures have already hit the 90s in parts of the state, and forecasters are predicting another hot summer.
Generators “get tested on their capability to operate under hot conditions. They get tested every summer,” he said.
Staff assume 100% of dispatchable generation summer capacity when compiling its seasonal assessments of resource adequacy (SARAs). However, wind and solar are only included under their historical performance for the recent top 20 peak-demand hours.
ERCOT continues to see new generation resources being added to keep up with the state’s growing economy and continued population growth. Utility-scale solar and battery storage projects make up almost 80% of the new resources being studied in ERCOT’s interconnection queue.
Responding to renewed regulatory and legislative scrutiny following the winter storm, ERCOT said it and Texas Reliability Entity staff will conduct site visits at about 30 power plants to evaluate their summer weatherization plans. The first-time summer spot checks will be similar to those assessing winter weatherization.
ERCOT’s preliminary fall SARA for October and November projects demand to peak at 62.7 GW. The grid operator warned that the grid might still face tight conditions if a high-demand day occurs when there is a combination of significant maintenance outages, low renewables production and/or extreme weather.
It also released its capacity, demand and reserves (CDR) report, which takes a longer-term view of grid conditions for the next five years.
Both reports take into account the impending transfer of nearly 500 GW of load when ERCOT adds the Lubbock Power & Light system over the Memorial Day weekend. The Texas Public Utility Commission last year approved the system’s transfer from SPP. (See Texas PUC Approves LP&L Integration Project.)
As an indicator of the media’s strong interest in ERCOT resource adequacy after February, media briefings such as Thursday’s now draw about 100 participants, staff said. A year ago, the briefings had maybe two dozen callers on the line.
