Since last winter, over 11,000 megawatts of generating capacity have been added to the ERCOT grid, Vegas said. That growth, which largely comes from battery storage and solar facilities, could be used to power about 2.8 million homes during periods of peak electric demand.
The overview
Under most weather conditions, there is a less than 2% chance of a grid emergency through February, ERCOT found in recent reports.
“Winter still represents the higher-risk period in the ERCOT market, because fewer [resources] are available during the winter peak periods, which tend to be in the mornings, before the sun rises, or in the early evenings, right after it sets,” Vegas told board members Dec. 9.
ERCOT forecasts that the tightest period this winter will be from 7-8 a.m. daily, when little to no solar power is being produced. During that time, ERCOT found the chances of a grid emergency are:This spring, the Texas Legislature passed Senate Bill 6, a state law aimed at increasing grid reliability and shielding residential customers from future power outages. Under that law, ERCOT could require data centers and other large electric consumers to supply backup power and switch to those reserves if grid conditions become tight. A “kill switch” provision in SB 6 gives ERCOT the authority to remotely cut power from large facilities in an emergency.
Officials previously said that new rules for large electric customers connecting to the Texas grid would be finalized in early- to mid-2026.
Zooming in
In February 2021, Winter Storm Uri brought days of below-freezing temperatures to Texas, which devastated a state power grid that was unprepared for the historic storm. Nearly 250 people died during prolonged power outages across the state, Community Impact reported.
In the nearly five years since Uri, tens of thousands of megawatts of capacity have been added to the grid annually. Energy providers are also required to “weatherize” their facilities to withstand extremely hot or cold temperatures after some power plants shut down due to the extreme cold in 2021.
Vegas said ERCOT has inspected over 4,000 facilities since the weatherization program launched in December 2021, and the agency plans to inspect at least 450 this winter. He said inspectors saw “significant improvements” in power plant performance due to the program, resulting in greater grid reliability.
Still, ERCOT’s models indicate that Texas could be in trouble if a storm similar to Uri hits large parts of the state this winter. If electric demand approaches ERCOT’s record of 85,508 megawatts, which was set in August 2023, there is a 62% chance of a grid emergency in December, a roughly 25% chance in January and about a 10% chance in February.
Demand could surpass 96,000 megawatts during extreme, Uri-like conditions, shattering previous records, ERCOT projects. However, the grid operator noted in its February report that the probability of a storm severe enough to cause over 96,000 megawatts of demand hitting Texas this winter is “well under 1 percent.”
The forecast
This winter is expected to be mild in Texas, said Dan Woodfin, ERCOT’s vice president of system operations.
“Even [with] an above-average temperature period over the course of the whole winter, that doesn't mean that we will not see a significant cold spell, or one or more significant cold spells,” Woodfin said Dec. 9. “I think there may be more potential for that this year.”
This winter could also “rank among the driest of winters” in Texas, Woodfin said in a presentation to the ERCOT board. Texas saw three cold snaps and snow in parts of the state last winter, Community Impact previously reported.
More details
Texans can sign up to receive notifications about changes in grid conditions at www.ercot.com/txans and register for ERCOT’s emergency alerts here. ERCOT issues the following advisories and alerts based on grid conditions:
- Weather watch: This advisory indicates that extreme weather may cause high electric demand and lower power reserves, although grid conditions are expected to be normal. ERCOT last issued a weather watch ahead of a February cold snap, Community Impact reported.
- Voluntary conservation notice: ERCOT asks residents to voluntarily reduce their energy use, if safe to do so, during a specific time period when demand is expected to be high with low wind and solar energy capacity. This was last used in January 2024.
- Conservation appeal: A conservation appeal is an “elevated request” for Texans to conserve energy during peak demand periods that could lead to a grid emergency. More information about conservation requests is available here.
- Energy Emergency Alert Level 1: ERCOT enters emergency operations if the grid’s operating reserves fall below 2,500 megawatts and are not expected to recover within 30 minutes. During this time, ERCOT may work with other grid operators to bring more power to the Texas grid. In comparison, ERCOT had over 14,900 megawatts of operating reserves as of press time, according to the agency’s grid conditions dashboard.
- Energy Emergency Alert Level 2: ERCOT may heighten emergency operations if reserves drop below 2,000 megawatts or grid frequency falls below 59.91 hertz. The agency can use strategies such as paying large industrial customers to reduce their energy use during this time.
- Energy Emergency Alert Level 3: During the highest level of emergency operations, ERCOT directs utility companies to conduct rotating power outages, which the agency said is a “last resort” to avoid a systemwide blackout. Per agency records, ERCOT last required rotating outages for about four days during Winter Storm Uri.
