Techno-economic analysis of a CO2 direct air capture-cooling tower hybrid process at a geothermal facility

Direct air capture (DAC) of CO2 can play a crucial role in global efforts to manage atmospheric concentrations of CO2, but the current cost-of-capture is prohibitively high. In this work we present a new DAC concept whereby cooling towers at geothermal power plants are hybridized to capture CO2 at very low cost. The system design is elegant in its ability to overcome key technical challenges and highlights the potential for using existing infrastructure to lower DAC cost and land footprint, and secure utilities and public confidence. The techno-economic analysis suggests a cost-of-capture of $100 per metric tonne of CO2 is feasible, allowing geothermal facilities to increase their net profit by $29 per metric tonne of CO2 captured — or $6 million per year — under the 45Q tax credit. If deployed at geothermal facilities in the United States, a net reduction of 270 million tonne CO2 per year is possible by 2050.