Do heat batteries make sense for data centers?

A newer kind of battery is getting attention for powering data centers, though it has little to do with home energy upgrades. "Heat batteries" store electricity as heat in materials like carbon blocks or ceramic, then either release that heat directly or convert it back into electricity using equipment like steam turbines. Companies including Antora Energy, Tempo Energy, and Rondo Energy are pitching these systems to data center operators, who need large amounts of reliable power fast as demand for computing grows.

Antora recently raised $550 million and, unlike in past funding rounds, emphasized data centers as future customers. The appeal is speed: Antora says it built a large storage system for a South Dakota biofuel plant in under a year, faster than many other options. The batteries can also discharge power for much longer stretches than standard lithium-ion batteries — up to 100 hours for Antora, and 12 to 24 hours for Tempo — which supporters say makes them a useful complement to lithium-ion systems already used for shorter bursts of grid power. Both companies say the materials involved are cheap and made domestically, which could mean lower costs and fewer supply problems, though no pricing details were shared.

None of these companies have announced signed data center deals yet, and no one has built heat batteries at large commercial scale so far. For now, this is a technology aimed at industrial sites and power grids, not something homeowners would install or benefit from directly.