A concrete thermal battery could be key to cooling data centers at scale — 150Kw prototype that can withstand up to 500 degrees centigrade is running

Researchers at Lehigh University have created a concrete thermal battery capable of storing 150 kilowatt-hours of energy. This innovative battery can endure temperatures up to 500 degrees Celsius during its thermal storage cycles. The concrete battery captures waste heat expelled by data center computing equipment and stores it for later use in cooling systems, industrial processes, electricity generation, and other thermal applications.

A prototype of the 150 kWh concrete thermal battery has been constructed, and tests indicate that it can withstand temperatures of up to 500°C. The battery can support flexible power generation, reduce industrial emissions, and facilitate high-temperature solar thermal operations at these extreme temperatures. After undergoing charging and discharging cycles, the battery demonstrates an efficiency exceeding 70%, ensuring that a significant amount of supplied energy remains recoverable after storage.

Engineered cement material is combined with embedded thermosiphons in the technology, which swiftly transfer heat through the storage medium during charging and discharging. These components rapidly move thermal energy while maintaining relatively stable temperatures, making the stored heat readily available when demand fluctuates. The system can also draw waste heat from servers and electricity, providing two charging routes for the storage unit.

Researchers describe the technology as a hybrid arrangement, combining various heat storage mechanisms within a concrete-based structure. This design enables thermal storage to operate independently from when waste heat is generated, offering greater timing flexibility. This flexibility is particularly valuable for facilities with fluctuating computing loads and varying cooling requirements throughout different operating periods.

Potential applications of the concrete thermal battery extend beyond data center cooling to electricity generation. In data centers, the technology can convert recovered heat into usable temperatures of between 120°C and 220°C, which can power absorption chillers for cooling, drying, district heating, and various industrial operations. The recovered heat can also power low-temperature Rankine cycle equipment, from kilowatt systems to megawatt-scale installations.

Absorption cooling is another possible application, allowing stored thermal energy to produce chilled conditions without solely relying on electrically driven refrigeration equipment. The researchers also highlight temperature upgrading as a crucial function, enabling recovered data center heat to reach higher usable temperatures.

The system can also function with electricity-driven heating, allowing operators to charge storage when electrical supply conditions make this approach practical. This flexibility can complement existing energy infrastructure while simultaneously recovering useful heat from nearby industrial operations and facilities.