Monday, 10 November, 2025/Edition 84

Geothermal power is increasingly drawing attention as a relatively clean, reliable source of energy, capable of offering independent (off grid) electricity to rural communities, military camps, and data centers. This week we will look at advanced or “next generation” geothermal systems.

Rasoul Sorkhabi

Editor, Core Elements

Unlocking Global Geothermal Energy

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The Washington D.C.-based Carnegie Endowment for International Peace has published a 72-page report on pathways for upscaling international deployment of next-generation geothermal power.

Next-generation geothermal (NG) systems: The conventional or hydrothermal systems are usually based on open-looped injection-production wells.

• NG systems include:

  • Closed-looped systems

  • Enhanced geothermal systems (EGS) involving hydraulic stimulation of hot dry rock

  • Tapping into supercritical water at deeper crustal temperatures of more than 400 °C

Global players: The United States is number one in total geothermal power production and technology, but most of the geothermal growth in the 21st century has occurred in Indonesia, Turkey, and Kenya.

The report categorizes countries into:

1. Power players or countries with legacy geothermal production: Germany, Turkey, Japan, Indonesia, Philippines, Mexico, Chile, Kenya, Taiwan

2. Second movers or countries with little historical geothermal capacity but that have policy and market indicators: Australia, France, Spain, Romania, Ethiopia, Vietnam, Colombia, Costa Rica, El Salvador 

3. Heat on the horizon, or countries with long-term potential: India, Malaysia, Saudi Arabia, UAE, Egypt, Morocco, Tanzania, Argentina, Brazil

Future trends: The report bets on price competitiveness of NG power by 2035 from current costs of more than U.S. $100–250 per megawatt-hour to less than $50–100, mainly due to technological advancements.

The report highlights the new synergy between subsurface technologies, oil and gas services, and NG power production.

Carnegie’s Report on the U.S.’ Competitive Advantage

Another Carnegie report focuses on U.S. geothermal power.

The report urges the U.S. industry to expand geothermal power because the country has technological advantages as well as geothermal resources.

Geothermal power offers three distinct uses:

1. Direct use through hot springs

2. Ground source heat pumps for individual buildings

3. Electricity generation

Low emission intensity:

• Geothermal power, like wind, solar, hydraulic, and nuclear power, has the lowest emission intensity of less than 100 grams of carbon dioxide equivalent per kilowatt-hour of electricity.

• This is far less than 400–650 for natural gas and 700–950 for coal.

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Utah’s Enhanced Geothermal System Project

Photo Courtesy of Rasoul Sorkhabi

Utah Frontier Observatory for Research in Geothermal Energy (FORGE) is a field-scale EGS laboratory funded by the U.S. Department of Energy and managed by the University of Utah’s Energy & Geoscience Institute.

An article in Leading Edge reports on the latest developments at FORGE.

Geological setting:

• FORGE is located west of the Mineral Mountains near Milford, central Utah.

• Situated in the Basin and Range Province, the area is characterized by stretched thin crust, Miocene-Recent igneous activity, and high geothermal gradient of about 2.24 °F per 100 feet.

• The target geothermal reservoir is Neoproterozoic granitic and gneiss complex covered with alluvial and volcaniclastic sediments.

Drilled wells:

• From October 2020 to January 2021, FORGE drilled an injection well, 16A, with a vertical depth of 8,559 feet and a total measured depth of 10,897 feet.

• Production Well 16B was drilled from May–July 2023 at a vertical depth of 8,357 feet and total measured depth of 19,947 feet.

• Wells 16A and 16B both run parallel, with Well 16B located about 300 feet above Well 16A.

• The build from the vertical to the lateral leg of the wells was at 65 degrees.

• Bottom hole temperatures are at about 450 °F.

Hydraulic fracturing:

• In April 2022, a three-stage stimulation without proppant was made at the toe of Well 16A to monitor the propagation of fractures.

• This was followed by stimulation with proppant of the lateral section of the injection well at eight stages and of the production well at five stages.

• Slickwater and crosslinked CHMHP were used as fluids for fracture stimulation.

• Hydraulic fracturing intersected pre-existing natural fractures.   

Well logging and coring:

• Injection and production drills have collected open-hole quad-combo (gamma-ray, sonic, density and porosity) logs as well as formation micro-resistivity image (FMI) and ultrasonic borehole imager (UBM) logs.

• Well 16A was cored at depths of 1,668–1,760 meters and 3,339–3,349 meters.

• Well 16B was cored at depths of 1,480–1,487 meters and 2,987–2,992 meters.

Micro-seismicity:

• Five vertical wells drilled to depths of 994–91.150 feet were equipped with geophones or fiber optic cables to monitor induced seismicity.

• During hydraulic fracturing, induced seismicity did not exceed a magnitude of 1.9.

Circulation tests:

• In April 2024, a nine-hour water circulation test was conducted. Water was injected at a rate of 15 barrels per minute and the outflow from the production well was up to eight barrels per minute. The water communication between the two wells had a fluid recovery efficiency of 70 percent and produced temperatures of 282˚F.

• An extended circulation test was conducted in August 2024. Nearly 64,000 cubic meters of water was circulated between the two wells at a rate of 1.59 cubic meters per second. The fluid circulation efficiency was nearly 90 percent and produced temperature was 380˚F.

Go deeper: For a field trip guide to geothermal power plants in Utah’s Great Basin see this GSA publication.

USGS Updates of the EGS Assessment in the Great Basin:

• In response to the Energy Act of 2020, the U.S. Geological Survey has updated its EGS resource assessment in the Great Basin.

• USGS’ 2008 report estimated how much electricity could be generated from EGS systems in the American West.

  • USGS 2025 estimates an upper limit of 174 terawatts-thermal of EGS power produced over 30 years from the upper seven kilometers of the crust, with one percent of these resources easily accessible.

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✉️ To get in touch with Rasoul, send an email to editorial@aapg.org.