A data center builder and a battery startup have agreed to deploy a novel type of energy storage for the first time at a U.S. data center. It’s the latest example of tech companies’ search for ways to manage the soaring energy needs of artificial intelligence.

Prometheus Hyperscale and XL Batteries will install what’s known as an organic flow battery at the one-gigawatt data center Prometheus is building in Wyoming. The project will begin as a small pilot in 2027 with plans to install another 25 megawatts of energy storage in 2028 and 2029. Organic flow batteries are unique because they don’t require lithium and rely instead on pumping positive and negative electrolytes through stacks of power cells to store and release energy.

The data centers that run artificial intelligence and cloud operations already require massive amounts of electricity, and the need is set to grow further. U.S. data centers will rise from 3.5% of total electricity demand today to 8.6% by 2035, according to BloombergNEF projections. That growth has utilities and hyperscalers searching high and low for electrons by building new gas plants, restarting retired nuclear facilities and digging deep into the ground to tap the Earth’s heat. Both traditional lithium-ion or unorthodox flow storage can store energy generated by renewables and help manage data center needs.

“We see unlimited demand and we hope by proving out the utility and capability of our technology, it’s the tip of the spear to do a lot more,” XL Chief Executive Officer Tom Sisto said.

There aren’t any known organic flow batteries installed at U.S. data centers, BloombergNEF head of battery technologies Evelina Stoikou said in an email, though she added that undisclosed projects could exist. XL’s organic flow batteries use salt water as the liquid, making them cheaper to build than vanadium-based systems in which that element is dissolved into sulfuric acid. Organic flow batteries also don’t rely on overseas lithium mines and can provide power for longer than lithium batteries, Sisto added.

“We need batteries that offer performance at or above lithium, without the risk of overheating to deploy at our data halls,” Prometheus CEO Trenton Thornock said in a statement. “XL Batteries’ organic flow battery technology offers a scalable, long-duration, non-toxic energy storage solution.”

The companies did not disclose the financial terms of the deal.

Prometheus has said its Wyoming data center will use natural gas and carbon capture and storage, and the company signed a letter of intent for power with Oklo, the advanced nuclear company backed by Sam Altman.

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