The U.S. Geological Survey today published the first map of the prospective locations of naturally-occurring geologic hydrogen resources in the contiguous United States, reflecting a systematic analysis of geologic conditions favorable for hydrogen that draws on a newly developed methodology.
The map is the first of its kind at continental scale anywhere, showing likely underground areas to explore for geologic hydrogen. It reveals areas of interest that have the potential to hold accumulations of geologic hydrogen, including a mid-continent region that covers Kansas, Iowa, Minnesota and Michigan, the Four Corners states of Arizona, Colorado, New Mexico and Utah, the California coast, and areas along the Eastern seaboard.
“For decades, the conventional wisdom was that naturally occurring hydrogen did not accumulate in sufficient quantities to be used for energy purposes,” said Sarah Ryker, USGS associate director for energy and minerals. “This map is tantalizing because it shows that several parts of the U.S. could have a subsurface hydrogen resource after all.”
Map showing prospectivity of geologic hydrogen in the conterminous United States.
In a recent paper, USGS geologists Geoff Ellis and Sarah Gelman estimated large potential for — and large uncertainty about — the amount of hydrogen accumulations in the world. “We calculate the energy content of this estimated recoverable amount of hydrogen to be roughly twice the amount of energy in all the proven natural gas reserves on Earth,” Ellis and Gelman wrote in their recent Science Advances paper.
However, the model makes no predictions about how or where this hydrogen is distributed in the subsurface. The authors note that much of it is likely too deep, too far offshore or in accumulations too small to be economically recoverable.
“We showed there is a significant potential for geologic hydrogen as an emerging energy resource. The next logical step was to find where it might be in the United States – and for that, we had to develop a methodology, which we applied first to the lower 48 states,” Gelman said.
The new USGS prospectivity map does just that, assessing which regions have the necessary geological conditions—hydrogen sources, reservoir rocks, and seals to trap the gas—for hydrogen accumulation. The map assigns relative prospectivity values from 0 to 1, and areas with higher values (deep blue on the map) are more prospective – likelier to contain geologic hydrogen accumulations than areas with lower values.
The map, which will continue to be updated as science and exploration progress, is an important first step in understanding a resource with potential to be a significant future energy resource for the U.S.
The USGS has a long history of providing resource assessments for oil and gas and is evaluating potential emerging resources that would enable states, industry and the nation to add to and diversify energy portfolios.
While there remains considerable uncertainty about the extent to which geologic hydrogen can contribute to meeting future energy demand, it has the potential to provide low-cost feedstock for critical chemicals and help decarbonize the energy sector.