Meeting Net-Zero America Direct Air Capture Targets with Sedimentary Basin Geothermal Heat While Considering Environmental Justice

Abstract

We investigate the potential of using sedimentary basin geothermal heat to drive solid-sorbent direct air capture (DAC) geospatially across the contiguous United States. DAC facilities are machines built for the purpose of removing CO2 from the air and require substantial amounts of heat. Sedimentary basin geothermal resources may be well positioned to provide this thermal energy because they are ubiquitous, do not require novel drilling technologies, have sufficient temperature to drive solid-sorbent DAC, and have not already been included in energy transition pathways. Here, we find that sedimentary basin geothermal resources could support almost 5 GtCO2/yr of CO2 removal capacity across the United States, which is an order of magnitude more DAC capacity than suggested needed for a 2050 netzero economy. There are multiple locations with sedimentary basin heat amenable for solid-sorbent DAC that are not typically considered for geothermal development (e.g., Louisiana, South Dakota). As the thermal energy demand of the solid-sorbent DAC system modeled in this study generally decreases with decreasing air temperature or relative humidity, the locations with the highest CO2 removal potential are those with both thermal energy resources and with lower air temperature and relative humidity. We also consider the location of disadvantaged communities within our analysis because energy development has not occurred equitably and the Justice40 initiative requires 40% of the benefits from federal investments in climate and clean energy go to disadvantaged communities. We find ~0.9 GtCO2/yr (~18%) and ~4 GtCO2/yr (~82%) of the total ~5 GtCO2/yr of CO2 removal capacity is located within, and outside of, disadvantaged communities, respectively. Overall, our study demonstrates that sedimentary basins could provide value to justice-centered pathways that meet mid-century energy transition goals by supporting DAC deployment.