Your AC might have a battery in it soon

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The grid is growing. Energy consumption by data centers alone grew 80% from 2020 to 2025, according to the International Energy Agency. Add in the steady march of electrification, from EVs to induction stoves, and utilities are staring down a demand curve they haven't seen in decades.

Utilities are struggling to keep up. New power plants take years to permit and build. Batteries, on the other hand, can be added to what's already there, faster and cheaper. That's turned batteries into the savior of the grid story right now, beating out solar, gas, and even nuclear. They're the thing making all the other power usable exactly when it's needed.

The big batteries

Grid-scale storage just had its best quarter ever. The U.S. installed almost 10 gigawatt-hours of battery capacity in the first quarter of 2026, up 32% from a year earlier, according to the Solar Energy Industries Association. Data centers, ironically the source of so much new demand, are also driving some of that buildout, as hyperscalers lean on batteries to get online faster and smooth out computing loads.

Globally, the picture is similar. Battery deployment grew 46% in 2025 to an estimated 250 gigawatt-hours worldwide, according to the energy think tank Ember, even as battery costs fell by roughly 45% for the second year running. That combination, more batteries and much cheaper ones, is what's letting solar power stick around after sundown instead of vanishing at dusk.

None of this happened overnight. One of the first grid-tied lithium-ion batteries went up 15 years ago in Chile’s Atacama Desert, a remote area with mining operations where steady power was hard to come by. But utility executives around the world mostly ignored the technology for years afterward, dismissing it as too expensive and too risky next to the coal and gas plants they already knew how to run.

That skepticism has mostly evaporated. Solar and wind costs have fallen for years, but batteries are now the standout, getting about a quarter cheaper in 2025 alone, according to BloombergNEF data, even as gas hit a record high. That widening price gap is letting batteries start to set the price of power instead of just supporting it.

And your little batteries, too

The cost curve is going down for batteries that are at the scale of a garage or a window unit. Batteries are migrating into the machines that already sit in American homes, and the target is the most electricity-hungry one of all: the air conditioner.

Carrier, the 120-year-old company that essentially invented modern air conditioning, is piloting central AC units with batteries built in, so the system can charge on cheap grid power and run on stored energy when demand spikes. Executives there point out that HVAC alone accounts for roughly 300 of the 750 gigawatts of peak capacity the U.S. grid has to handle. Shift even a fraction of that load off-peak and the effect on the wider system is enormous.

Startups are chasing the same opening from a different angle. Every Electric, based in New York City, ships portable power banks that plug into window AC units and switch them onto battery power during periods of peak grid strain, all managed through software that treats thousands of individual apartments as one coordinated resource.

Cars are joining in too. Electric vehicles already carry some of the biggest batteries most households own, and vehicle-to-grid technology lets them send power back to the system during evening demand peaks, then recharge overnight when electricity is cheap and plentiful. Rooftop solar households are stacking home batteries on top of that, enrolling in virtual power plants that let utilities draw on thousands of garages and basements like a distributed power plant.

Batteries aren't risk-free. A fire at a storage facility in California's Monterey County last year forced evacuations and renewed local pushback against big installations, even though the battery chemistry involved has mostly been phased out. Recycling systems and the supply chains for materials like lithium are still catching up to how fast the industry is scaling.

But still, costs probably haven't hit the floor yet. If batteries keep getting cheaper and safer, the grid problems they're solving today, from data center demand to overloaded circuits during a heat wave, might just be the start of what they can fix.