Drilling for Hydrogen
As the global push for diversified energy sources continues, hydrogen has emerged as a key contender, both as a climate-friendly option and as a means of bolstering energy independence and economic resilience. Among the various methods of hydrogen production, an intriguing possibility has come to the forefront: geologic hydrogen or “natural hydrogen,” a resource naturally generated and stored beneath the Earth’s surface. This resource of the future combines some “best of” characteristics in energy: a fuel source that can be domestically produced, results in no greenhouse gas emissions when combusted, and has the potential for scalable, long-term supply. Here, we explore its potential and examine the current state of exploration in the U.S. and globally.
What is Geologic Hydrogen?
Geologic hydrogen, often referred to as “white” or “gold” hydrogen, is naturally occurring hydrogen gas found in underground reservoirs. Unlike hydrogen produced through electrolysis or steam methane reforming, geologic hydrogen forms through natural geological processes, including:
- Serpentinization: A chemical reaction between water and certain iron-rich rocks.
- Radiolysis: The splitting of water molecules by natural radiation deep within the Earth.
These processes create hydrogen that can accumulate in subsurface traps, much like natural gas. And like natural gas, hydrogen offers a domestically available energy source, with concomitant economic and national security benefits.
Mapping Hydrogen as a Resource: The USGS Effort
In a groundbreaking step, the U.S. Geological Survey (USGS) has released the first-ever map identifying potential geologic deposits across the contiguous United States. This map highlights several promising regions, including:
- The mid-continent region (Kansas, Iowa, Minnesota, and Michigan).
- The Four Corners area (Arizona, Colorado, New Mexico, and Utah).
- Coastal areas along California and the Eastern seaboard.
USGS’s Geologic Hydrogen Prospectivity initiative map provides a critical foundation by identifying favorable geological settings for production and accumulation.
ARPA-E’s Push for Innovation
The Advanced Research Projects Agency-Energy (ARPA-E) funded 16 projects with $20 million to advance the exploration and potential production of geologic hydrogen. These projects aim to:
- Stimulate generation in subsurface environments.
- Develop technologies for efficient extraction and monitoring.
- Understand the economic and technical feasibility of large-scale production.
Using Battery Technology to Target Underground Hydrogen Production
The University of Southern California is adapting oil and gas techniques to optimize extraction. Eden GeoPower is exploring subsurface battery technology to enhance production.
Subsurface battery technology refers to an innovative approach where electrochemical systems are deployed underground to manipulate geochemical conditions, thereby stimulating production. This technology leverages controlled electrical currents to alter redox conditions in geological formations, enhancing reactions that release hydrogen from minerals or organic matter trapped within rock structures.
By acting as an in-situ energy storage and delivery system, subsurface batteries can facilitate continuous or pulsed energy input directly at the reaction sites, optimizing the efficiency of hydrogen generation processes. This method could be useful in deep geological environments where traditional surface-based stimulation techniques can be less effective due to energy dissipation over distance.
Are Hydrogen Pilot Projects on the Horizon?
In a positive development, several exploration companies are actively preparing to drill for geologic hydrogen in the U.S.:
- HyTerra Ltd.: Preparing for pilot drilling in the Nemaha Ridge area of Kansas, having secured over 9,500 acres of leases.
- H2Au and 45-8 ENERGY: Planning exploratory wells in Kansas under the Humboldt Project, with drilling expected to commence by 2026.
- Natural Hydrogen Energy LLC: Drilled the Hoarty NE3 well in Nebraska, encountering elevated hydrogen concentrations and signaling potential for further testing.
These initiatives signal a nascent growing momentum, suggesting that pilot projects targeting natural hydrogen could be realized within a few years.
Challenges and Opportunities
While the prospects are exciting, significant challenges remain. Key hurdles include:
- Developing a firmer understanding of the size of the resource.
- Understanding the economic viability of geologic production.
- Developing advanced extraction and monitoring technologies.
- Addressing regulatory and environmental considerations.
To address these concerns, ARPA-E has funded Argonne National Laboratory to develop a comprehensive Life Cycle Analysis (LCA) methodology for geologic hydrogen. This work will assess the environmental impacts and energy efficiency of geologic production from extraction through end-use. The LCA will provide critical data to guide industry and policymakers in evaluating the impacts of the entire infrastructure needed.
In addition to life cycle considerations, the storage of geologic hydrogen is emerging as a crucial area of focus. Recent studies on reservoir engineering aspects highlight the importance of developing effective subsurface storage solutions similar to those used for natural gas (salt domes and depleted gas reservoirs). Key challenges include maintaining purity, minimizing leakage risks, and optimizing storage and retrieval efficiencies under varying subsurface conditions. These advancements will be essential for integrating geologic hydrogen into the broader energy system, enabling it to serve as a reliable and scalable resource.
Despite these challenges, the potential benefits are immense. Geologic hydrogen offers a domestically available energy source that could strengthen U.S. energy security and reduce reliance on external supplies. By prioritizing energy independence, geologic hydrogen exploration aligns with broader strategic goals, even in administrations focused less on environmental factors and more on economic growth and energy production. In addition, research and development is proceeding globally.
Conclusion
The work on geologic hydrogen complements the modeling efforts undertaken by OnLocation using the National Energy Modeling System (NEMS). OnLocation has developed hydrogen models for clients, integrating them with NEMS to evaluate the impacts of emerging technologies and policies on the U.S. energy system. These models are continually updated to reflect recent policy changes and technological advancements, providing comprehensive insights into future energy scenarios. To learn more about these efforts, please visit: Challenges of Modeling Hydrogen in the U.S. Energy System.