Winter Storm Fern, which swept through the U.S. over the weekend, marked a major test of the Texas grid’s resiliency, five years after Uri devastated the state, leaving millions without power and killing hundreds. It was a test that the grid mostly passed — despite the freezing temperatures and ice that blanketed much of the state, and worries over tight power conditions.
Some of this came down to reliability upgrades.
ERCOT analysts and energy experts told Latitude Media that gas plants and wind turbines were less vulnerable to icy conditions than they were in 2021, in part due to weatherization mandates from state officials. Few plants went offline during the storm — a stark departure from when gas well heads and pipelines froze during Uri, causing rolling blackouts and skyrocketing electricity prices. Since then, Texas has also added more than 14 gigawatts of new battery storage capacity, some of which kicked in during critical windows Monday and Tuesday morning when demand spiked as residents and businesses turned on the heat.
“The gas, coal, and nuclear fleet was all significantly more reliable this time around, and then the batteries gave Texas the flexibility that those other generators don’t,” said Stephen Ryan, power market analyst at Wood Mackenzie.
Luck played another role: There was more wind and less ice than forecasters feared in the lead-up.
Ryan said that wind generation “overperformed.” Output was nearly six GW higher on Saturday and three GW higher on Sunday than Wood Mackenzie had forecasted. For every megawatt of wind on the grid, there’s less need for more expensive fossil fuels, he said. Renewables help drive down the cost overall of the entire system.
That said, the grid still suffered the effects of some ice. Nearly 40,000 homes and businesses were without power as of Tuesday morning, they were mostly in East Texas, where local outages from frozen or downed power lines were concentrated.
ERCOT’s ability to weather the storm could be a glimpse at the future for other grid operators; Texas leads the nation in renewables and storage deployment, and has become a test bed for the energy transition. Fern has demonstrated that a mix of winterized power generation can absorb shocks to the system, and — especially if the wind cooperates — temper skyrocketing prices. Analysts told Latitude Media that grid reliability doesn’t come from certain technologies winning, but rather from fossil fuels, solar, wind, and battery storage all covering the weaknesses of each other.
“If you compare our grid in 2026 to what it looked like in 2021, we were way more dependent on gas as a single resource back then,” said Matthew Boms, executive director of the clean energy trade group Texas Advanced Energy Business Alliance. “Now we’ve got a really diversified fuel mix.”
Real-time storm tracking
ERCOT’s data shows how these resources deployed in real-time during the storm as demand spiked.
Gas is the largest energy resource in Texas and accounted for anywhere between 40% and 70% of the fuel mix between Saturday and Tuesday — with the highest penetration overnight as temperatures dropped. Wind accounted for between 7% and 30%, performing best over the weekend.
In the leadup to the winter storm, there was a speculation that batteries would help avert an energy crisis. ERCOT in December reported an emergency was less likely because of the growing number of storage projects connected to the grid.
However, battery operators largely didn’t fire off until Monday and Tuesday morning. Boms explained this was by design, given those were the riskiest hours for the grid — which is typically the mornings, when “people wake up, they turn on the heat, the lights, the hot water, and businesses start running,” he said.
Batteries are designed to meet that peak demand, especially true in times of grid stress.
“Most batteries have about two to four hours of full output,” Boms said. “So operators want to save those hours for when demand is highest, or a plant trips offline, or the system is close to emergency conditions. They’re meant to respond when the grid is under real stress. So the fact that they stayed quiet and then surged on Monday morning shows the market is working.”
ERCOT had forecast demand to spike to 83 GW on Monday morning, which would have nudged up against its expected seasonal capacity of 91GW.
That level didn’t materialize, however, likely due to business closures. Demand peaked at about 76GW instead, and batteries met about 9% of that demand, while gas supplied much of the rest until solar came online.
