The Advanced Research Projects Agency-Energy (ARPA-E) of the U.S. Department of Energy has issued a Request for Information (RFI) under DE-FOA-0003494 to gather insights on potential programs focused on exploring geologic hydrogen resources. This RFI seeks feedback on innovative technologies and methods that could support the discovery, evaluation, and economic assessment of natural hydrogen accumulations or enhanced hydrogen production from geologic formations. The goal is to develop approaches that improve the identification, characterization, and potential yield estimation of these resources while minimizing greenhouse gas emissions and meeting future hydrogen demand.

ARPA-E is particularly interested in technologies that can detect naturally occurring subsurface hydrogen or identify formations suited to hydrogen stimulation through processes like serpentinization, where hydrogen is generated from iron-bearing minerals in rocks, and radiolysis, where natural nuclear reactions in water produce hydrogen. The agency specifies that it is not interested in proposals related to conventional fossil fuel hydrogen conversion, standard industrial hydrogen production methods such as electrolysis, or conventional drilling outside established fields.

The RFI outlines several key areas of interest. First, ARPA-E seeks feedback on exploration strategies for hydrogen-specific subsurface exploration, including approaches for selecting promising geological formations, defining drilling criteria, and using non-invasive geophysical methods. Responses are encouraged to address criteria for identifying reservoir quality, locating optimal drilling sites, and using data from unsuccessful drilling attempts to refine exploration methods.

Geologic hydrogen systems represent another area of interest, particularly regarding the processes of natural hydrogen generation. Respondents are invited to discuss minimum economic generation rates, migration limits between source rocks and reservoirs, and the potential impact of dynamic subsurface conditions on long-term resource evaluations.

The agency is also interested in mapping and surveying methods that could enhance hydrogen exploration. ARPA-E invites proposals for mapping innovations that may include space-based or aerial surveys, integration of machine learning, and adaptations from mining or oil and gas methods. Challenges related to surface gas sampling and geochemical analysis are also a focus, with ARPA-E looking for insights on how these methods might be used to infer subsurface hydrogen potential.

Subsurface geophysical exploration methods are another focus, with ARPA-E seeking to understand how non-invasive imaging and borehole logging can be adapted to hydrogen. Respondents are encouraged to discuss advancements in tomography, aerial subsurface imaging, and other techniques that could improve the accuracy and scale of hydrogen exploration while reducing associated costs.

For drilling and core analysis, ARPA-E seeks insights into technologies that could make hydrogen-specific drilling more effective, including improvements in horizontal drilling, core analysis for resource estimation, and mud-logging tailored to hydrogen exploration. Additionally, ARPA-E seeks feedback on monitoring and characterization innovations that could aid in hydrogen reservoir management, such as environmental impact assessments, monitoring of induced seismicity, and techniques for tracking hydrogen leakage. This area also includes interest in developing production well designs and methods for fracture monitoring.

Finally, ARPA-E addresses offshore exploration considerations, especially for the continental shelf. Here, responses are encouraged to discuss how methods from the oil and gas industry could be adapted for hydrogen, the need for novel geophysical sensors, and the assessment of environmental impacts. Offshore exploration innovations for cost-effective methods and adapted drilling technologies are also of interest.

ARPA-E encourages responses from a broad array of participants, including academic institutions, industry stakeholders, and research entities, to address these exploratory areas. Feedback should focus on cost-effective, environmentally sustainable approaches to geologic hydrogen exploration, resource characterization, and possible production methods. All information provided will contribute to ARPA-E’s program planning and development; however, this RFI does not offer any funding opportunities at this stage. Responses are due by December 2, 2024.