The United States Department of Energy (DOE) has selected 21 projects to receive more than $99m in funding to advance geothermal energy development nationwide.
The programme will support field-scale testing of enhanced geothermal systems (EGS) and exploration drilling at sites with potentially valuable geothermal resources.
Five projects will test next-generation geothermal technologies under real-world conditions, while a further 16 will drill into promising geothermal resources to improve understanding of subsurface conditions.
The DOE says the work is intended to reduce technical and development risks and provide data that can support future commercial projects and investment.
The projects span several states and will investigate resources ranging from conventional hydrothermal systems to hot, impermeable rock that could potentially be engineered to produce geothermal power.
Data generated through the work will also be made publicly available through the DOE’s Geothermal Data Repository (GDR), extending its potential value beyond the individual projects.
DOE Under Secretary of Energy Kyle Haustveit believes the investment will unearth vital energy resources: “These projects will empower American innovators to unlock the tremendous geothermal resources beneath our feet.
“We’re advancing next-generation geothermal technologies that can lower costs, strengthen American energy dominance, and turn more of our vast domestic geothermal resources into reliable and affordable power.”
How does geothermal energy work?
Geothermal energy uses heat from beneath the Earth’s surface.
Where naturally occurring heat, fluids and permeable rock are accessible, geothermal resources can be used to generate electricity. These are known as hydrothermal resources.
Enhanced geothermal systems take a different approach. EGS technologies seek to create or improve underground reservoirs in hot rock where natural permeability or fluid circulation is insufficient.
Wells can be drilled into suitable formations and engineered to enable circulation, allowing heat to be brought to the surface.
The technology is attracting attention because geothermal resources can provide power continuously rather than depending on when the sun is shining or the wind is blowing. The DOE is therefore pursuing geothermal technologies to access more of the US’ domestic geothermal resources.
Five projects will test geothermal technologies in the field
A central part of the funding will support five field-scale EGS demonstrations.
Rather than testing technologies solely in controlled environments, these projects will operate at depths and temperatures relevant to eventual geothermal development.
Fervo Energy Company, based in Houston, will drill, complete and stimulate EGS wells in Elmore County, Idaho.
The project will also deploy a high-temperature, three-component geophone array at temperatures of at least 200°C, alongside seismic and geochemical analysis carried out with national laboratories.
In New Mexico, Zanskar Geothermal and Minerals will work at the Lightning Dock Geothermal field in Hidalgo County. Its project will involve drilling and hydraulically stimulating a short-lateral horizontal injection well.
The aim is to provide engineered pressure support to an existing hydrothermal reservoir while also accessing heat from nearby impermeable hot rock.
Another AlterG Resources project will test EGS in Nevada’s Pershing and Churchill Counties. The company plans to use a deep horizontal well pair to evaluate the technology at commercially relevant depths, while comparing two approaches to hydraulic stimulation.
The University of Utah will undertake another EGS demonstration at Nevada’s Dixie Valley West geothermal field.
The project will develop and operate an EGS doublet to examine whether engineered reservoirs alongside existing hydrothermal systems can sustain circulation and deliver commercially relevant thermal output.
Quaise Energy will push geothermal technologies into particularly high-temperature conditions at the southern flank of Newberry Volcano in Oregon.
The demonstration will target bottomhole temperatures of 265°C to 365°C, above the range in which many conventional EGS tools and materials have been validated.
Exploration drilling will target new geothermal resources
The other 16 projects will focus on exploration drilling.
Their purpose is to gather the subsurface information needed to better understand, and potentially confirm, promising geothermal resources.
Several projects will examine areas where geothermal potential has been identified but where reservoir conditions remain uncertain.
DAVINCI EP will drill two paired horizontal confirmation wells in California’s Brawley Known Geothermal Resource Area.
The work will investigate a naturally enhanced hydrothermal reservoir without stimulation and collect information that could support commercial-scale development.
In Utah, the University of Utah will investigate a large thermal anomaly at the Cove Fort geothermal field. Drilling, logging and data integration will be used to examine how heat and fluids are distributed through carbonate rock formations.
Elsewhere, GeoAlaska will drill and test a confirmation well on the southern flank of Mount Augustine in Alaska. The project will investigate the subsurface using wells targeting temperatures above 150°C and above 350°C.
The programme also includes exploration work at sites in California, Washington, New Mexico, Oregon, and Idaho.
Projects will use drilling, temperature measurements, geological and geophysical surveys, reservoir testing and modelling to build a clearer picture of conditions below the surface.
Public data could support future development
An important feature of the DOE programme is that the information generated will not remain confined to individual project teams.
Data from the field tests and exploration activities will be made available through the DOE’s GDR.
For geothermal developers and researchers, better information about underground temperature, geology, permeability and reservoir behaviour can help inform future exploration and technology development.
The DOE says making the data publicly available can therefore extend the value of the projects beyond the sites receiving funding.
Together, the 21 projects are intended to address two of the challenges facing wider geothermal deployment: proving that next-generation geothermal technologies can work at relevant scale and improving knowledge of where viable resources exist.
By combining field demonstrations with exploration drilling, the programme will generate both operational experience and new subsurface data that could inform future commercial geothermal energy development across the US.
