Innovative Thermal Storage for Data Centers

Engineers at Lehigh University have introduced a novel concrete thermal battery designed to capture and repurpose the massive amounts of waste heat generated by modern computing equipment. This development addresses the growing challenge of energy efficiency in data centers by transforming heat that would otherwise be discarded into a versatile energy resource.


The research team has successfully constructed a prototype boasting a 150 kWh storage capacity. During rigorous testing, the battery demonstrated the ability to endure extreme operating temperatures of up to 500°C, proving its robustness for high-demand industrial environments.


Technology and Mechanism

The system functions as a hybrid thermal storage unit, utilizing specialized engineered cement integrated with embedded thermosiphons. These components facilitate the rapid movement of thermal energy throughout the storage medium during both charging and discharge cycles. This ensures that the system maintains a stable thermal profile, making stored heat readily available even when external energy demands fluctuate.


The flexibility of the design allows it to be charged in two distinct ways:

  • Direct capture of waste heat from server cooling systems.
  • Utilization of electrical heating inputs, providing operators with options based on electricity supply conditions.

According to researchers, the efficiency of the battery remains remarkably high, with more than 70% of supplied energy recoverable after a complete cycle.


Practical Applications and Efficiency

By upgrading recovered data center heat to a range of 120°C to 220°C, the technology opens doors to several practical applications. «This approach gives operators another way to use heat that conventional cooling equipment normally removes before releasing it directly outside,» the research team noted.


Potential uses for this stored thermal energy include:

  • Absorption Cooling: Generating chilled air without a complete reliance on traditional electric refrigeration.
  • Industrial Processes: Supporting drying operations and district heating systems.
  • Power Generation: Driving low-temperature Rankine cycle equipment at scales ranging from kilowatts to megawatts.

Future Outlook

This innovative project received backing from federal energy funding and has already been licensed to a private entity. By allowing data centers to connect with local thermal grids, the technology could significantly reduce the carbon footprint of computing facilities. As the project advances, it aims to integrate seamlessly into existing energy infrastructure, proving that industrial waste heat can be turned into a sustainable and valuable asset.