A sudden blackout across Spain and Portugal earlier this month left 50 million people without electricity. While the cause of the outage is unclear, a leading culprit appears to be poorly integrated wind and solar resources. What’s clear is that, in an increasingly digital age, ensuring affordable and reliable power is more critical than ever.

The Spain-Portugal blackout came as U.S. power regulation authorities sounded an alarm about the safety of America’s electric grid and power supply. The North American Electric Reliability Corporation (NERC) — the nation’s grid reliability regulator — warned that parts of America’s power grid could fail during a heatwave this summer.

Why is America’s power grid looking so shaky? And could Spain’s massive blackout happen here?

Each summer, U.S. electricity demand soars. And when Americans crank up their air conditioners amid scorching summer heat, regional utilities must meet that hefty additional demand.

The problem is that there might not be enough electricity to go around.

The United States is suddenly using a lot more electricity than before. Electric vehicles, new manufacturing plants, and an exponentially growing array of data centers — which support the digital needs of cell phones, web browsers and AI systems — are gobbling up power. Power demand is growing so fast that, in the past year, NERC found America’s peak electricity needs grew by a staggering 10 gigawatts. That’s more than double the growth seen between 2023 and 2024.

Surging demand is also colliding with the remnants of a regulatory agenda that aimed to wipe out America’s coal power plant fleet and make it impossible to build coal and natural gas power plants. While the Trump administration has worked to undo this misguided regulatory blitz, grid operators have lost essential dispatchable power plants that work on demand. They’re now increasingly reliant on renewable power systems subject to the weather’s whims.

Because of this, NERC says that grid operators “face challenges in meeting higher demand this summer with a resource mix that, in general, has less flexibility and more variability.”

The greatest threat to grids nationwide will be heat waves when demand spikes. Windless, scorching summer days — and evenings when solar power disappears — could leave grids alarmingly short of supply.

The nation’s energy regulators recognize there’s a power supply emergency. Federal Energy Regulatory Commission Chairman Mark Christie has observed that America is now “losing dispatchable generation at a pace that is not sustainable, and we are not adding sufficient equivalent generation capacity.”

A power supply operating on the margins is a recipe for disaster. The Iberian blackout was a timely reminder of the risks we face. It’s time to heed the warnings of our grid operators and reliability regulators and rebuild solid, long-term electricity generation while there’s still time.

Terry Jarrett is an energy attorney and consultant. He served on the board of the National Association of Regulatory Utility Commissioners and the Missouri Public Service Commission.