Concrete thermal battery stores 150 kWh and survives 500°C

A new concrete thermal battery from Lehigh University could help data centers reuse heat that would normally be wasted. The prototype stores heat at high temperatures and can release it later for cooling, power generation, or other industrial uses. The team says the 150 kWh storage is enough to support a range of high-temperature needs while keeping the system compact enough for real-world facilities.

The battery operates by cooling servers and other equipment and then storing that heat inside a concrete medium. Embedded thermosiphons move heat through the material during charging and discharging, so heat can be tapped quickly when demand shifts. The researchers say this hybrid approach combines cement-based storage with different heat-transfer methods to enable faster response times and more flexible timing than conventional cooling alone.

Testing shows an efficiency greater than 70% over a full charging and discharging cycle, meaning a large portion of the stored energy remains usable after storage. The design also allows charging from electricity or directly from waste heat, creating two routes to power the system depending on what’s available at any moment.

Applications aren’t limited to cooling. For data centers, the system can push heat into a useful temperature range of about 120°C to 220°C, which could feed absorption chillers or other high-temperature processes. In other words, the stored heat could help run cooling and other operations without drawing as much electricity from the grid during peak times.

Officials say the project could eventually connect with existing energy networks and broader industrial needs. The research received federal funding and has been licensed to a private energy company, signaling a path toward real-world deployment beyond the lab.

What this means for the everyday data consumer is simpler cooling bills and a potential reduction in the energy footprint of large computing facilities. If it scales, many data centers could reuse waste heat instead of dumping it, improving efficiency without requiring major new infrastructure investments upfront.

Looking ahead, researchers will likely test larger versions and explore how this concrete battery could integrate with district heating networks or industrial heat users. The question for operators is whether this approach can deliver steady, cost-effective cooling and energy at scale, without adding maintenance headaches.