How to Net-Zero America: Nationwide Cost and Capacity Estimates for Geologic CO2 Storage

Abstract

Reaching a US net-zero carbon economy may require drilling and operating hundreds of CO₂ injection wells by 2030 and thousands by 2050 in deep saline formations. Accomplishing this scale of infrastructure deployment will require a coordinated effort across all sectors of the economy. A first step is estimating the cost and capacity of geologic CO₂ storage across the entire country to provide high-level guidance for national geospatial infrastructure decisions. Prior to this study, such an analysis had not been completed because it requires a combination of a fast-running, physics-based software tool and a fine-resolution nationwide database of geologic properties, which did not exist. Here, we addressed this gap by constructing the Sequestration of CO₂ Tool (SCO₂T^PRO) geodatabase to provide the first-ever cost and capacity screening estimates for onshore geologic CO₂ storage across the United States.

Using the SCO₂T^PRO screening estimates, we find that there is a substantial capacity of low-cost CO₂ storage in the United States, but that this capacity is not uniformly distributed across the country. For example, there are regions of the country with capacity for geologic CO₂ storage, but the cost of that capacity can vary widely. Overall, this finding demonstrates that simply having a deep saline geologic resource in a given location does not always mean geologic CO₂ storage is a viable option for decarbonization efforts. This result underscores the crucial importance of geospatial planning for reaching net-zero by midcentury. For example, geologic CO₂ storage is widely regarded as critical for decarbonizing “hard to decarbonize” sectors of the economy (e.g., cement production), but our results show there are portions of the country where widespread low-cost CO₂ storage is unavailable. As reaching net-zero nationwide requires addressing the emissions from every region in the country, our results imply that identifying plausible pathways for decarbonizing these “hard to sequester” regions should be prioritized.

Additionally, our results also demonstrate that knowledge of capacity and injectivity are insufficient indicators for identifying low-cost CO₂ storage. This finding may have large ramifications for reaching net-zero because, currently, preliminary CO₂ storage site characterization typically entails estimating the capacity and injectivity across various potential sites, and then using that information to down-select locations for more detailed and expensive characterization efforts. We show here that these intermediate results are not always robust indicators of low-cost resources and that preliminary site-characterization activities should go beyond capacity and injectivity to also consider cost.