Life Cycle Greenhouse Gas Emissions of CO<sub>2</sub>-Enabled Sedimentary Basin Geothermal
Lily Liu, Marcos M. Miranda, Jeffrey M. Bielicki, Brian R. Ellis, Jeremiah X. Johnson
Abstract
The expansion of renewable energy and the large-scale deployment of carbon dioxide (CO 2 ) capture and storage (CCS) can decarbonize the power sector. The use of CO 2 to extract geothermal heat from naturally porous and permeable sedimentary basins to generate electricity (CO 2 -plume geothermal (CPG) system) presents an opportunity to simultaneously generate renewable energy and geologically store CO 2 . In this study, we estimate the life cycle greenhouse gas (GHG) impacts of CPG systems through 12 scenarios in which CPG systems are combined with one of six CO 2 sources (e.g., bioenergy with carbon capture and storage (BECCS) and iron and steel facilities) and operate in two geological settings. We find the life cycle GHG emissions of CPG systems ranging from −0.25 to −6.18 kg CO 2 eq/kWh. CPG systems can achieve the highest emissions reductions when utilizing the CO 2 captured from BECCS. We evaluate uncertainty through a Monte Carlo simulation, demonstrating consistent net reductions in life cycle emissions and a local, one-parameter-at-a-time sensitivity analysis that identifies the CO 2 capture capacity as the high-impact parameter of the results. Through the production of electricity, CPG systems can provide additional environmental benefits to the deployment of large-scale CCS.