Geothermal Energy
Our renewable energy future begins at INL
What is geothermal energy?
Geothermal energy harnesses natural heat stored in the Earth’s crust to generate clean, reliable and continuous power, contributing to a more resilient energy future.
The Earth has produced heat since it was formed. The temperature at the core — 6,000 degrees Celsius — is roughly the same as the surface of the sun. This heat radiates out through our planet’s mantle and crust, but until now, human efforts to harness it have only scratched the surface.
At INL, we’re proud to be at the forefront of geothermal research and testing. With our expertise and cutting-edge technology, INL is leading the way in the use of geothermal as a clean and sustainable energy source.
How do geothermal power plants work?
To produce power, geothermal power plants rely on steam generated by the earth’s heat to turn turbines and generate electricity.
There are three types of geothermal power plants: dry steam, flash steam and binary cycle.
At these power plants, water deep in the ground is heated up to 150 degrees Celsius (302 Fahrenheit) by the Earth, producing steam. The steam is directed through pipes and pushes a turbine, which generates electricity. The steam is pushed into a condenser, where it cools and becomes a liquid which is pumped back into the reservoir.
At these power plants, water deep in the ground is heated up to 150 degrees Celsius (302 Fahrenheit) by the Earth, producing steam. The steam is directed through pipes and pushes a turbine, which generates electricity. The steam is pushed into a condenser, where it cools and becomes a liquid which is pumped back into the reservoir.
Binary cycle stations use a mix of water and liquids with a lower boiling point than water.
The water, which can be as cool as 57 degrees Celsius (135 Fahrenheit), is drawn into the plant where heat exchangers transfer heat to the second liquid, usually a hydrocarbon, refrigerant or water-ammonia mixture.
The second liquid becomes steam, which powers turbines or generators, before it is cooled in a condenser and recycled to become steam again.
Why use geothermal power?
- Clean and renewable: Geothermal energy produces minimal greenhouse gas emissions and operates 24/7, providing a reliable and consistent power source.
- Stable energy costs: Geothermal power is insulated from fuel price fluctuations, offering long-term stability in energy costs.
- Local economic growth: Geothermal projects create jobs, stimulate local economies and enhance energy independence.
- Reduced carbon footprint: Geothermal energy plays a vital role in reducing reliance on fossil fuels, contributing to global efforts to combat climate change.
- Reliable: Geothermal plants provide carbon-free power around-the-clock.
Innovation in Harnessing the Earth's Heat
Led by some of the field’s most prominent researchers, INL is developing cutting-edge geothermal energy technologies to generate clean, reliable and continuous power, and create a more resilient energy future.
Enhanced Geothermal Systems (EGS)
EGSs are geothermal reservoirs where there is hot rock but limited pathways fluid can flow through. In EGS development, drilling a pair of wells from the surface into the hot subsurface rock and injecting fluid opens or reopens fractures, enabling water to carry energy back to the surface and generate electricity. It has been estimated that EGS has the potential to provide up to more than 100 gigawatts of electricity to more than 100 million American homes.
Experts estimate EGS could provide electricity for more than 100 million American homes. EGS doesn’t require preexisting subsurface water or permeable rock.
For more information about this work and potential partnership opportunities, please contact [email protected].
INL is leading the Snake River Geothermal Consortium, one of five groups pursuing the development of Enhanced Geothermal Systems (EGS) for the U.S. Department of Energy (DOE).
Geothermal Energy Storage (GeoTES)
Geological Thermal Energy Storage (GeoTES) is using a geological formation as a battery, storing energy in the form of heated liquid during times of excess energy generation and releasing it during times of peak energy demand.
By storing excess energy from intermittent sources such as solar and wind, GeoTES could play a significant role in assisting with peak demand ramping, easing stress on transmission and providing grid stabilization. In addition to storing energy, using GeoTES to heat and cool buildings can result in energy savings between 30% and 80%.
For more information about this work and potential partnership opportunities, please contact [email protected].
Hybrid Geothermal
Renewable energy sources like wind and solar can experience fluctuations in power output. Hybrid systems combining different energy sources can address this challenge, reducing the levelized cost of energy.
Idaho National Laboratory and National Renewable Energy Laboratory (NREL) collaborated with Enel Green power to quantify the economic benefits of combining geothermal and solar thermal systems, leading to the world’s first triple hybrid renewable energy plant in Stillwater, Nevada.
For more information about this work and potential partnership opportunities, please contact [email protected].
Mineral Production
Geothermal power plants produce a complex saline solution from far underground called geothermal brines. These brines often contain commercially viable concentrations of minerals such as lithium. Studies have suggested that if battery-grade lithium can be extracted from geothermal brine, 11 existing geothermal plants along Southern California’s Salton Sea alone could produce enough lithium annually to meet current U.S. demand, eliminating the need for imports. Geothermal fluids are consequently able to produce energy as well as precipitate critical minerals needed for battery production.
Our team at INL has been awarded funds for two projects characterizing lithium and other critical materials for both the Smackover Formation in Louisiana and the Paradox basin in Utah.
For more information, please contact [email protected] or [email protected]
Discovery and Exploration
In 2022, the U.S. Department of Energy announced EGS Energy Earthshot, a program seeking to cut the cost of geothermal systems to $45/MWh by 2035. A 2023 report from National Renewable Energy Laboratory (NREL) suggested the total amount of installed geothermal in the U.S. could grow by 10 times by 2035. The nation’s deep EGS resource potential — made up of heat trapped deep in the Earth that can be found virtually anywhere — is “huge,” the report suggested.
In 2023, DOE’s Geothermal Technology Office issued a funding opportunity for $74 million to support seven pilot projects to demonstrate different geologic settings, development techniques and well orientations. The agency will explore four topics as part of its pilot demonstrations.
- EGS demonstrations using existing infrastructure that is close to existing geothermal or hydrothermal development.
- “Green field sites,” well-characterized sites with no existing geothermal development, but with potential for sedimentary, igneous or mixed metamorphic rock with near-term power production potential.
- Demonstrations to address super-hot or supercritical EGS resources (of more than 375 degrees C).
- EGS demonstrations at “a well-characterized eastern U.S. site” with near-term power and thermal power production potential.
For more information about this work and potential partnership opportunities, please contact [email protected].
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