A new initiative led by the National Renewable Energy Laboratory (NREL), with funding from the U.S. Department of Energy’s (DOE) Geothermal Technologies Office, is exploring the potential of geothermal underground thermal energy storage (UTES) technology to tackle cooling challenges in data centres.
Traditional data centre cooling relies on methods like water-cooled fan coils or direct water-based cooling for computing equipment. While geothermal electricity generation has been a viable solution for the sector’s constant cooling and power needs, the Cold Underground Thermal Energy Storage (Cold UTES) project seeks to push the boundaries further. By integrating geothermal storage, the project aims to reduce cooling loads, enhance infrastructure resilience, and provide a stable cooling source. This innovation could lessen the reliance on building additional power plants specifically for data centre cooling needs.
Researchers explain the technology
“The approach we're taking is to look into the technical and economic viability of the proposed Cold UTES technologies by projecting what data center loads will look like over the next 30 years,” said Guangdong Zhu, a senior researcher in NREL’s Center for Energy Conversion and Storage Systems and principal investigator for the Cold UTES project. “We’ll then do some projections and grid-scale analysis to show what this technology could look like if it's commercially deployed at a large number of data centres. We’re aiming to improve grid resilience and reduce the cost of required grid expansion.”
Cold UTES leverages off-peak power to create a cold energy reserve stored underground, which can then be used to support existing data centre cooling systems during peak grid load hours. This charge and discharge process is optimised based on time-of-use and other grid parameters, functioning similarly to a conventional battery system. However, unlike traditional grid batteries, Cold UTES offers the added capability of long-duration energy storage, extending beyond daily cycles to accommodate seasonal energy demands. This dual functionality not only enhances grid efficiency but also significantly reduces overall operating costs.
“Our expectation is that a Cold UTES system can provide a long-duration energy storage and industrial-scale cooling solution that is commercially attractive and technically viable for data centres,” said Jeff Winick, technology manager at DOE’s Geothermal Technologies Office. “This project will confirm the potential of these systems to provide significant savings and value to data centre operators, utilities, and grid system operators.”
Researchers at Lawrence Berkeley National Laboratory, Princeton University, and the University of Chicago are also involved in the project.
“The idea of Cold UTES is super exciting because it's a novel player in the space of data centre energy management and cooling,” said Andrew Chien, a professor of computer science at the University of Chicago. “I can't think of another technology focused on storing cold with new opportunities to make data centres more efficient.”
“This project will help accelerate the development, commercialisation, and use of next-generation geothermal energy storage technologies,” Winick said, “thereby establishing American global leadership in energy storage.”