Thermal energy storage (TES) company Brenmiller has developed a solution for data center cooling which utilizes crushed rocks to capture air and water.

The new Cold Thermal Storage Energy (CTES) system, named bGen Cool, uses the company’s proprietary technology, which it currently deploys to utility companies and in other industrial settings.

Brenmiller has decided to expand into the data center market amid a rapid build-out of digital infrastructure to meet soaring demand for AI services.

The company’s core TES product converts electricity into heat that it says can power sustainable industrial processes at a price that is said to be competitive with natural gas.

Known as bGen, it charges by capturing low-cost electricity from renewables or the grid and stores it in crushed rocks. It then discharges steam, hot water, or hot air on demand according to customer requirements.

Israel-based Brenmiller says it can convert this system to store cold water or air required for data center cooling with what the company describes as “minimal investment.”

“Data center needs are not too dissimilar from those of our flagship customer base, except they require cold water or air instead of heat or steam,” said Avi Brenmiller, chairman and CEO of Brenmiller Energy. “With fairly straightforward modifications to our bGen design, we are confident in our ability to deliver a cost-competitive and energy-efficient data center cooling solution to the market.”

Brenmiller adds that, as a modular system, bGen “aligns with the data center industry’s trend toward prefabrication and modular solutions.”

TES is technology being investigated by several companies for use in data center settings. In April, OpenAI CEO Sam Altman and venture capital firm Andreessen Horowitz (a16z) joined a $20 million funding round for Exowatt. The US startup is building thermal batteries capable of storing solar energy so it can later be deployed by data center operators.