Texas is heading into summer 2026 with a power grid under pressure from two directions. Data centers and large computing facilities are adding enormous, continuous electricity demand. At the same time, summer nights are getting warmer, reducing the overnight cooling the grid once relied on, keeping residential air conditioners running long after dark. Regulators are still writing the rules for those new industrial loads, but ERCOT’s own planning documents already show where the pressure is building: in the evening hours, when solar output fades but demand does not. That is where cooling homes that cannot cool down and data centers that never switch off collide, and it is exactly where the grid is most exposed.
There is a moment in a Texas summer night, usually around 2 a.m., when you expect the heat to finally relent. For most of the 20th century, that moment was reliable. Engineers built demand curves around it. Rate structures were calibrated to it.
But that moment is becoming less reliable.
What scientists call elevated nighttime minimum temperatures—and what Texans would refer to simply as nights that never cool off—is reshaping the state’s energy picture in ways that broad averages can obscure. When nighttime temperatures stay high, air conditioners run through the night. People who need sleep to recover from heat exposure don’t get it. The electricity grid, planned around a daily demand cycle with a reliable overnight drop, finds itself sustaining load that used to fade by midnight.
As this summer approaches, regulators are still working to close the gap. Just weeks ago, the Public Utility Commission of Texas published proposed Senate Bill 6 interconnection rules setting steep financial security and disclosure requirements for large loads connecting to the grid. The full five-track rulemaking won’t produce final rules until late 2026, well after the peak season. The urgency is visible in last year’s data. In 2025, ERCOT’s summer high reached 83.9 gigawatts on August 18, while a new all-time winter peak of 80.6 gigawatts was set in February, both in the same calendar year. A grid once defined by one brutal season now faces sustained pressure in two. ERCOT’s own reporting confirms that tightest operating conditions now occur not at the afternoon peak, but in the evening hours as solar ramps down while load remains high.
ERCOT’s Capacity, Demand and Reserves report, using its updated 2025 load forecast, indicates that planning reserve margins for the peak net load hour could enter negative territory as early as this summer under above-normal conditions. (The peak load hour margin does not go negative until summer 2027.) The North American Electric Reliability Corporation’s 2025 Summer Reliability Assessment found that ERCOT expects adequate resources under normal conditions, while evening hours carry heightened reliability risk as solar output falls and load stays elevated, with the highest-risk window identified around 9 p.m. These are not projections from outside critics. They are the grid operator’s own numbers, and the season that will test them is weeks away.
What makes the approaching season different from previous near-miss summers is the convergence of those two demand pressures. Because Texas operates largely as an isolated grid, it cannot easily draw on neighboring regions when those pressures converge, the full weight falls on a system designed to carry it alone.
The first is structural load growth. The EIA projects electricity demand within ERCOT will rise by roughly 14 percent in 2026 as large data centers and cryptocurrency mining facilities come fully online. Industry tracking indicates ERCOT entered 2026 with more than 230 gigawatts of large-load interconnection requests in its queue, nearly quadruple the level from the prior year. These facilities create a continuous baseline of demand that the grid has to meet at all hours, not just during the afternoon peak.
The second pressure is residential cooling demand that is both growing and shifting later into the night. According to the NOAA’s annual climate report, 2024 was Texas’s warmest year on record. The summer of 2023 saw ERCOT demand peak at 85,508 megawatts, the all-time grid record. In May 2025, during a heat event that would have been unremarkable in August a decade ago, ERCOT set a new May demand record of 78,392 megawatts, topping the prior May record of 77,139 megawatts set in 2024. The high-demand season is starting earlier and lasting longer. The overnight recovery window the system was calibrated to is shrinking.
Together, these two forces are revealing a gap between what the Texas grid was planned to handle and what it is now being asked to support. The system is operating under higher levels of demand than its original design assumed, and that gap is widest not at noon, but in the evening, when industrial load continues uninterrupted and cooling demand no longer drops the way the engineering once counted on.
Texas has made real progress in grid modernization. Solar generation has expanded rapidly: utility-scale solar in ERCOT produced nearly four times as much electricity in the first nine months of 2025 as it did in the same period in 2021. Battery storage capacity has roughly tripled since 2023, providing support in the evening hours as solar rolls off the system. But solar peaks at noon, not at 9 p.m., and batteries sized to manage a few hours of evening ramp-up cannot carry the grid through a night when temperatures stay high and industrial load continues uninterrupted.
Those planning assumptions are now being tested under conditions they were not built around.
Closing that gap requires investment in grid flexibility and longer-duration storage. Demand-response policies that give large industrial loads financial incentives to curtail during peak hours are a start. SB 6, passed during the 89th legislative session, moves in that direction by tightening interconnection and reliability requirements for very large loads and creating tools for load reduction and backup generation coordination during emergencies. The harder problem is overnight duration: storage that can carry the grid for hours beyond the evening ramp, through the stretch of night when industrial demand does not let up and cooling demand no longer drops.
Texas built its grid for a climate that no longer fully exists. The assumption of overnight demand relief, baked into decades of engineering and planning, is losing its reliability. A grid that now has to carry continuous industrial load through nights that no longer cool down is a different system than the one regulators and operators designed for. Updating it is not optional.
Meeting that challenge is not a concession to weakness. It is the infrastructure work that sustained economic growth now depends on.
The post Texas Nights Are Getting Hotter, and the Power Grid Isn’t Ready appeared first on The Texas Observer.
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