by Wedan Emmanuel Gnibga & Andrew A. Chien
Datacenter (DC) power demand is rapidly growing to support AI workloads. With increasing pressure to reduce water consumption, DC cooling power can be up to 30% overall DC power, reducing IT power capacity. Cooling is especially power-demanding during hot periods, which often coincide with peak grid loads and insufficient renewable generation, increasing costs and carbon emissions. Exacerbating the problem is growing compute power density. Rack power densities have grown from under 20kW (2010) to more than 120kW (today), and could reach 1MW (2029). Conversely, cooling and power distribution are not scaling in density, so their space use grows in proportion. This limits DC scalability and lifetime.
We explore the benefits of augmenting DC cooling with cold Underground Thermal Energy Systems (Cold UTES), a technology with no water consumption, well-suited to water-stressed regions. Cold UTES can store thermal energy in underground formations (e.g., natural reservoir or shallow rock) during off-peak times and release it to cool DCs during peak periods. Results show this can increase IT capacity by 9.8% across regions, and improve cooling power efficiency, reducing on-peak power use (e.g., 44.4% in Texas), operational carbon emissions (e.g., 10.4% in Arizona), and cooling costs (e.g., 3.4% in Arizona). Cold UTES can improve DC scalability, extending DC lifetime from one to three generations (2 to 6 years).
In The News
