As temperatures climb across much of the United States this week, the country's power grid is facing a familiar summer test — with a new factor making it harder.

Heat drives demand toward records

With temperatures reaching around 100 degrees Fahrenheit (38 degrees Celsius) across the eastern half of the country, and humidity pushing the way the heat feels still higher, electricity use has surged as air conditioners run flat out. PJM Interconnection, the largest grid operator in the United States, warned of record summer demand and issued hot-weather alerts, Al Jazeera reported. In New England, demand reached its highest level since 2013, and wholesale electricity prices briefly spiked — the U.S. Energy Information Administration noted prices jumping above $1,300 per megawatt-hour, many times the normal rate.

A new strain on the system

For roughly two decades, total U.S. electricity demand barely grew, as efficiency gains offset rising use. That era is ending, driven substantially by data centers — the warehouses of computer servers that power artificial intelligence and cloud computing. They now account for a large and growing share of new electricity demand, and the biggest "hyperscale" facilities can each draw between 100 and 300 megawatts, as much as a small city. That steady, heavy load leaves less slack for the peaks that heatwaves create — and the data centers' own cooling needs rise just when the grid is most stressed.

Emergency measures

The squeeze has prompted unusual steps. PJM sought federal authorization to curtail power to data centers equipped with backup generators as a last resort to prevent rolling blackouts, Utility Dive reported — a striking illustration of the tension between the rapid build-out of AI infrastructure and the reliability of power for ordinary households. The U.S. Department of Energy framed such measures as a way to "prevent avoidable blackouts."

The bigger debate

The episode has sharpened a debate over how the United States will keep the lights on as demand rises. Utilities and policymakers are weighing how much new generation to build and what mix to favor — natural gas, renewables, nuclear, or keeping older coal plants running longer — against the costs to consumers and the climate. Extreme heat itself is becoming more frequent as the planet warms, adding to the pressure.

For now, the U.S. grid has weathered recent heatwaves without widespread blackouts, and operators expressed confidence they could manage this one. But the margin is narrowing. As the demands of cooling and computing increasingly collide, this week's heat offers a preview of a challenge that is only set to grow.