Non-evaporative district cooling cuts costs, saves water, and eases grid pressure in tropical cities

Tropical coastal regions face rapidly growing cooling demand, increasing pressure on electricity systems and freshwater resources. Conventional water-cooled chillers are energy- and water-intensive, exacerbating grid vulnerability and water scarcity under hot, humid conditions. Here we present a comparative techno-economic assessment of three district cooling strategies: a conventional chiller system, a ground heat exchanger-assisted system, and a geologic seawater air-conditioning system that accesses cold seawater through inland wells. Using a case study at the University of Puerto Rico at Río Piedras, we show non-evaporative systems reduce water use and operating costs. The ground heat exchanger-assisted system lowers the levelized cost of cooling by 52%, while the geologic seawater air-conditioning system achieves 70–90% lower costs than the baseline and eliminates water consumption. It also decreases peak electricity demand, demonstrating a pathway to decouple cooling from water and grid constraints in tropical coastal cities. These findings highlight the potential of non-evaporative district cooling to improve resource efficiency and support resilient cooling infrastructure. Non-evaporative district cooling cuts cooling costs by 52% to 90%, eliminates water use, and reduces peak electricity demand, according to a techno-economic assessment of ground heat exchanger and geologic seawater cooling systems.