The majority of outages within the Texas grid during a February cold snap were weather-related, a preliminary report from the Electric Reliability Council of Texas (ERCOT) found.
At peak, 54% of generator outages in the region were caused by weather-related issues, during the Feb. 14-19 time period, while 14% of outages were caused by equipment failures and 12% by fuel limitations. Approximately 51,173 MW were forced offline during that period, according to ERCOT's analysis, sent to the Texas Public Utility Commission Tuesday, down slightly from the grid operator's original estimate of 52,277 MW.
Weather-related outages were defined by the grid operator as outages "explicitly attributed to cold weather," including frozen or flooded equipment. ERCOT is still waiting on data from the full event, which lasted from Feb. 10-19.
ERCOT's report is based on initial requests for information from generators about why so much generation fell offline during the cold weather event that left millions without power for days, and killed 125 Texans, according to the latest data from the Texas Department of State Health Services.
Texas' grid operator was forced to trigger outages after almost half the region's power generation fell offline unexpectedly, causing a critical demand-supply mismatch that brought ERCOT dangerously close to a multi-week black-start event.
Since the outages, generators, the gas industry and lawmakers have debated whether the state should take a more stringent approach to weatherization. Following similar outages in 2011, guidelines were developed that recommended how generators should approach weatherization, but no regulator-enforced mandate exists in the state.
Lawmakers are currently mulling legislation that would overhaul energy regulation in the state, including requiring the Texas Railroad Commission, which oversees oil and gas, and the PUC to implement rules for weatherization. The bill passed the Senate last week and companion legislation is now being considered in the House.
The data released Tuesday does not break down outages by resource, though it notes that weather-related outages could include frozen lines or valves, ice accumulation on wind turbines, ice or snow cover on solar panels, exceedances of low temperature limits for wind turbines, or flooded equipment due to snow melt. Previously reported ERCOT data found that gas outages were the most pervasive, exceeding 25,000 MW in outages at its peak, followed by wind at below 20,000 MW.
But although the grid operator did not include unit-specific outages, it did note that wind and solar-related outages appear higher than other resources because the report is based on nameplate capacity, and those resources would not generally be expected to perform at their maximum capacity. ERCOT said it will ask generators to waive confidentiality of the specific reported causes of generator outages once it receives the data from Feb. 10-13.
"The final event analysis report for the February 2021 extreme cold weather event will provide an even more comprehensive set of information on generator outages and their causes," the grid operator wrote in its letter to PUC Chairman Arthur D'Andrea, estimating the full report will be available no later than the end of August.
D'Andrea resigned from the commission last month, following pressure from the governor, but said he would remain on the commission until his replacement is appointed. Gov. Greg Abbott, R, last week forwarded the nomination of Will McAdams, who is currently president of the Associated Builders and Contractors of Texas, and his confirmation remains pending in front of the state senate.