Mapping the Weather-Water Nexus: Comparing the Performance, Weather Sensitivity and Water Consumption for Liquid-Solvent Direct Air Capture

Direct air capture (DAC) is a promising carbon dioxide removal (CDR) technology essential for meeting global climate goals. To achieve gigatonne-level CO2 removal by 2050, DAC systems must be scaled beyond their current capacity of capturing only tons to thousands of tons annually. One of the main challenges in scaling DAC is the significant impact of local weather conditions, particularly temperature and humidity, on performance and water consumption. Solvent-based DAC systems are particularly sensitive to these factors, with water consumption often posing a critical constraint in arid or water-stressed regions. Our study developed a process-level model of a liquid-solvent DAC system, coupled with a 20-year dataset of hourly temperature and humidity data at a 10 km resolution across the Conterminous U.S. The results reveal that the average water consumption varies by a factor of more than two seasonally, with humidity exerting a greater influence on water consumption (63%) than temperature, while CO2 capture efficiency is more temperature-dependent. This disparity underscores the need to assess site-specific weather patterns to optimize both DAC performance and resource use. Despite the substantial differences in regions optimized for CO2 capture versus water efficiency, we identified the Southeastern U.S. and coastal Western U.S. as the most favorable locations for DAC deployment due to their balance of high capture efficiency and relatively lower water demands. However, the seasonal misalignment between peak performance and water consumption in certain areas of the Conterminous U.S. complicates deployment strategies and system design. This work provides insights into optimizing DAC site selection by balancing CO2 capture efficiency and water consumption, informing sustainable, large-scale DAC deployment that minimizes environmental impacts and operational costs.