| Title | A Techno-Economic Model of a Data Center with Cold Underground Thermal Energy Storage |
|---|---|
| Authors | Erik Witter, Hyunjun Oh, Rebecca Barney, Guangdong Zhu, Joshua McTigue |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | The global expansion of data centers leads to a surge in electricity consumption and places a significant load on the power grid and increases grid connection requirements. Cold underground thermal energy storage (Cold-UTES) is one solution for managing data center cooling loads. These systems leverage the natural thermal capacity of the earth by chilling the subsurface during off-peak hours and seasons and using the resource to provide cooling during peak periods. Cold-UTES has opportunities in scenarios where water usage must be minimized: Cold-UTES reduces water usage compared to evaporatively-cooled systems and reduces electricity consumption compared to dry air-cooled mechanical chillers. We describe a data center cooling system that includes Cold-UTES. We develop a techno-economic model of this systems to illustrate the potential to manage cooling loads – and particularly to minimize energy consumption at times of peak grid stress (which often coincide with higher electricity prices). The techno-economic model evaluates the performance and cost of a data center cooling system comprising mechanical chillers, free coolers, and Cold-UTES, and accounts for variation in ambient dry-bulb temperature and data center load. A simple dispatch approach is developed which determines which cooling system to use depending on the ambient temperature and the grid price. This model is used to evaluate the quantity of energy used a peak grid times and to demonstrate how Cold-UTES can benefit the data center by reducing grid connection requirements and minimizing operational costs compared to a data center that does not use Cold-UTES. |