How much hydrogen awaits us underground?

Barbara Sherwood Lollar, a geochemist at the University of Toronto, has revealed new insights into the potential of geologic hydrogen, based on decades-old data from the Kidd Creek mine in northern Ontario. Her findings suggest that the mine releases approximately 140 metric tons of hydrogen annually through its vents, offering a glimpse into the vast reserves of the gas that may exist beneath the Earth's surface. The study, published in the Proceedings of the National Academy of Sciences, highlights the ongoing quest to harness naturally occurring hydrogen as a sustainable alternative to fossil fuels. Lollar and her colleague Oliver Warr analyzed data collected from 35 boreholes at Kidd Creek over more than a decade. Each borehole consistently emitted an average of eight kilograms of hydrogen per year. When extrapolated to the more than 14,000 boreholes present in the mine, this translates to a total annual release of roughly 140 metric tons. While this quantity is not sufficient to meet global energy demands, it represents a promising step toward understanding the feasibility of using geologically sourced hydrogen as a clean energy resource. The discovery builds upon earlier work conducted in the 1990s, when Lollar and her team identified microbial life thriving in ancient brine deep within the mine. These microorganisms were found to subsist on hydrogen generated through chemical reactions between water and surrounding rock. This revelation sparked renewed interest in the potential of geologic hydrogen as a renewable energy source, particularly given the environmental challenges associated with conventional hydrogen production methods. Hydrogen fuel holds significant promise as a versatile power source, capable of powering everything from vehicles to industrial machinery. However, current production methods often result in high greenhouse-gas emissions and require more energy input than the gas itself provides. The prospect of tapping into naturally occurring underground reservoirs of hydrogen, referred to as “geologic hydrogen”, could revolutionize the industry by providing a cleaner, more efficient alternative. Efforts to locate and exploit such reservoirs have gained momentum globally. Companies like HyTerra in Australia and Koloma, backed by Bill Gates, are actively searching for ancient rock formations in the U.S. Midwest that may host hydrogen-producing environments. Meanwhile, researchers at the U.S. Geological Survey estimate that trillions of tons of hydrogen are continuously generated within Earth’s crust. If even a small fraction of this could be extracted, it might satisfy global hydrogen demand for centuries. Despite these encouraging developments, the search for commercially viable hydrogen deposits remains elusive. To date, no known site has demonstrated the capacity to produce hydrogen in quantities suitable for large-scale energy applications. Public data on exploration outcomes remains limited, as companies strive to maintain competitive advantages while attracting investment. The Kidd Creek findings contribute to a broader scientific consensus that natural hydrogen generation is a real and ongoing geological process. Laurent Truche, a geochemist at the University of Grenoble Alpes in France, notes that similar observations have been made at the Bulqizë chromium mine in Albania, where at least 200 metric tons of hydrogen flow annually. Truche emphasizes that the key challenge lies not in proving the existence of natural hydrogen, but in demonstrating its economic viability and reliability at commercial scales. Researchers and startups are also investigating ways to enhance hydrogen production through technological interventions. By injecting water, heat, or catalytic agents into reactive rock formations, scientists aim to accelerate the natural hydrogen generation process. Over a dozen such initiatives are currently supported by the Advanced Research Projects Agency-Energy (ARPA-E), which has set ambitious goals to increase hydrogen production rates by a factor of 10,000. This level of enhancement could potentially render geologic hydrogen a practical and scalable solution for meeting future energy needs.