Geospatial techno-economic and environmental assessment of different energy options for solid sorbent direct air capture

Summary: Direct air capture (DAC) is a promising carbon dioxide removal technology, but its effectiveness hinges on access to cheap, low-carbon energy. Here, we present a spatial techno-economic and environmental assessment of the coupling of solid sorbent DAC with different energy sources. We found that the most cost- and energy-efficient option is to couple DAC with thermal power plants, e.g., nuclear and natural gas combined cycle with carbon capture. These two options have a gross levelized cost of DAC (LCODgross) starting at $246–$503 and $314–$557 per tCO2, respectively, for different regions. For renewable energy and energy storage options, regions with good solar irradiation can achieve low LCODgross, at $319 per tCO2 when utilizing concentrated solar power, whereas regions with low solar irradiation are unsuitable for this option due to the high cost and large land requirement. Achieving an LCODgross of ≤$200 per tCO2 would require significant improvements in the current technology. Science for society: Cost-effective transition pathways to keep global temperature rise below 2°C require billions of tons of CO2 removal from the atmosphere annually. Direct air capture (DAC) offers advantages like permanent storage of CO2 with low land use but it is energy-intensive. Thus, sustainable and cost-effective large-scale DAC deployment needs optimal site identification for cheap, low-carbon energy and regional co-benefit maximization. This study presents a global assessment of DAC energy supply options, including conventional and renewable energy sources, considering region-specific factors. Our analysis identifies the most suitable energy supply options for different regions, assessed based on techno-economic and environmental performance and potential co-benefits. The results help provide a foundation of evidence that will be essential for developing business models, strategies, and policies for the sustainable and cost-effective large-scale deployment of DAC systems.