- Concrete thermal batteries could turn data center waste heat into usable energy
- Lehigh researchers develop a thermal battery with 150 kWh storage capacity
- The concrete battery withstands temperatures reaching 500°C during thermal storage operations
Engineering researchers at Lehigh University have developed a concrete thermal battery that could help data centers reuse heat removed from computing equipment.
The system stores recovered heat before releasing it for cooling, industrial processes, electricity generation, and other applications requiring thermal energy.
A prototype with 150 kWh storage capacity has been fabricated, while testing shows the system can withstand temperatures reaching 500°C.
Concrete battery stores recovered heat for data center cooling
At such temperatures, the technology can support flexible power generation, industrial emissions reduction, and high-temperature solar thermal applications.
After testing, the reported efficiency after a complete charging and discharging cycle exceeds 70%, meaning substantial supplied energy remains recoverable after storage.
The technology combines engineered cement material with embedded thermosiphons that transfer heat through the storage medium during charging and discharge
These components move thermal energy rapidly while maintaining relatively stable temperatures, allowing the stored heat to become available when demand changes.
The system can accept waste heat from servers as well as electricity, creating two routes for charging the storage unit.
Researchers describe the technology as a hybrid arrangement because it combines different heat storage mechanisms within a concrete-based structure.
The design also allows thermal storage to operate separately from the moment when waste heat is produced, providing greater timing flexibility.
That separation could matter for facilities where computing loads fluctuate significantly and cooling requirements change during different operating periods.
Potential applications extend from data center cooling to electricity generation
For data centers, the technology can upgrade recovered heat into a range between 120°C and 220°C for useful thermal applications.
That temperature range could supply absorption chillers for cooling, while stored heat could also support drying, district heating and industrial operations.
This approach gives operators another way to use heat that conventional cooling equipment normally removes before releasing it directly outside.
The system can therefore connect computing facilities with nearby thermal demands, potentially allowing recovered energy to serve purposes beyond immediate cooling.
Stored heat can also drive low-temperature Rankine cycle equipment, with possible installations ranging from kilowatt systems through facilities operating at megawatt scale.
Absorption cooling offers another application, allowing stored thermal energy to produce chilled conditions without relying entirely on electrically driven refrigeration equipment.
The team also describes temperature upgrading as an important function when recovered data center heat needs to reach higher usable temperatures.
The system can also operate with electricity-driven heating, allowing operators to charge storage when electrical supply conditions make that approach practical.
Such flexibility could complement existing energy infrastructure while recovered heat continues serving nearby industrial operations in practice.
This technology was partly funded by Federal energy, and it has now been licensed to a private energy company, allowing further development toward integration with existing energy infrastructure.
The project could eventually connect thermal storage with existing energy networks while recovering useful heat from industrial operations and nearby facilities.
