The U.S. Geological Survey (USGS) has indicated that geothermal energy in Nevada’s Great Basin and adjoining areas could potentially supply electricity equivalent to one-tenth of the current U.S. power demand.

This represents a significant increase from current levels, as geothermal energy currently contributes less than 1% to the national power grid. The report updates a previous assessment from 2008 and emphasizes the role of enhanced geothermal systems (EGS) in unlocking this potential.

The study covers the arid lands of the Great Basin, including parts of California, Oregon, Idaho, Wyoming, and Utah. The projected 10% contribution to national electricity needs hinges on widespread commercial-scale development and ongoing technological advancements, particularly those developed in the geothermal and oil and gas sectors over the past few decades.

According to the USGS, most existing geothermal electricity generation relies on hydrothermal systems where groundwater naturally circulates through heated, permeable rock. However, the bulk of geothermal potential lies in areas where heat is trapped in impermeable rock. In such cases, EGS is required.

These systems involve engineering open fractures into impermeable rock as deep as 3.7 miles (6 kilometers) below the Earth’s surface, allowing water to circulate and extract heat for electricity generation.

The new assessment incorporates technological developments in mapping and subsurface surveys, including the use of artificial intelligence and machine learning. New heat flow and underground temperature maps were created, along with methods to estimate energy extraction efficiency and the conversion of heat into electricity.

The USGS assessment of undiscovered geothermal resources reflects future potential and areas that have not yet been fully explored or developed.

Sarah Ryker, acting USGS director, stated that the Great Basin was selected due to its known history of geothermal activity and that current findings indicate even greater potential for baseload power than previously understood.

“Leveraging this work along with artificial intelligence and machine learning techniques will help us assess the entire nation’s potential for geothermal energy with greater speed and accuracy,” she said.

The USGS also highlighted the dual benefit of modern mapping techniques, which now support the identification of geothermal energy, critical minerals, and, in some cases, groundwater. While the geothermal heat in the Great Basin has been confirmed, realizing its full potential depends on further improvements in engineering efficiency and the commercial deployment of enhanced geothermal technologies.

 

If enhanced geothermal systems (EGS) technology advances as projected, the potential for power generation from these systems significantly increases with depth, as deeper rock formations tend to be hotter.

While depths exceeding 6 km might necessitate further technological breakthroughs, the current provisional estimate for the Great Basin, spanning 633,072 sq km, suggests a total EGS power production capacity of 135 GW.

This figure represents only 0.5% of the accessible electric-grade resource, indicating that 99.5% of the thermal energy remains as residual.

Notably, thermal resources from active hydrothermal systems, which account for less than 1% of the total rock volume, are not factored into this estimate. This new assessment aligns with the 518 GW estimated in the 2008 geothermal assessment for the upper 6 km of the larger western U.S., with Nevada and Utah alone contributing an estimated 150 GW.

While it is improbable to achieve the most extreme production efficiencies, these values establish a spectrum for the resource, ranging from negligible (if suitable geological conditions are scarce) to an impressive 44% of the resource base becoming useful. This upper bound could result in an astounding 13 TW of power, roughly ten times the current U.S. power generation capacity.

Earlier this year, the U.S. Department of the Treasury and the Internal Revenue Service released final rules for the clean electricity investment and production tax credits (technology-neutral credits). The final rules clarify which clean electricity zero-emission technologies qualify for the credits. These include wind, solar, hydropower, marine and hydrokinetic, geothermal, nuclear, and specific waste energy recovery technologies.